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Transition metal catalyzed carbonylation reactions of a wide range of organic compounds provide entry to some molecules of value to the pharmaceutical, commodity, and petrochemical industries. Examples to be presented include the preparation of indolizine derivatives by palladium-catalyzed oxidative alkoxycarbonylation, the synthesis of N-fused heterocycles via dearomatic carbonylation, the highly regioselective and chemoselective carbonylation of bifunctional organic reactants with haloarenes, styrenes, and alkynes. These transformations were successfully applied to the synthesis of natural products including Avenanthramide A

Catalysis is a general process that speeds up the reaction rate without altering the process thermodynamics. It is often essential to study the kinetics of the reaction to infer the mechanism of catalysis, an insight that can help in catalyst design. However, bulk catalysis, and specifically electrocatalysis, cannot capture the inherent heterogeneity of seemingly identical catalysts. This talk aims to provide basic principles behind electrocatalysis and introduce a new way to study electrocatalysts at the single entity level. Together, we will review the latest progress in the field and conclude with future directions that can be applied to the vast majority of catalysts ranging from organic, bio, and inorganic materials.

Functional materials are the main building blocks of advanced technologies based on energy storage and conversion systems essential for our modern life including batteries, solar cells, and heterogeneous catalysis. Improvements in materials performance and development of new materials rely on our ability to obtain structure-function correlation as well as understand degradation processes when the materials are integrated into a device. To this end, advanced analytical tools that can provide information at the atomic level are essential. Solid-state nuclear magnetic resonance (ssNMR) spectroscopy is well suited for this task, especially when equipped with high sensitivity by Magic Angle Spinning - Dynamic Nuclear Polarization (MAS-DNP). However, to date, the majority of materials studied by MAS-DNP were non-reactive and non-conductive materials with DNP from exogenous sources of polarization such as nitroxide radicals. This approach cannot be simply extended to functional materials as the properties that stem from the material’s functionality in the device, including electrical conductivity, chemical reactivity and defects, often pose challenges in the study of the materials by DNP. In this talk I will frame the challenges associated with the application of MAS-DNP to functional materials and describe approaches to address them. Results will be presented from three ubiquitous material systems spanning a range of applications: carbon allotropes, transition metal dichalcogenides (TMDs) and metallic microstructures. We systematically investigated the deleterious effect of materials’ conductivity and formulated means to reduce the effect. We explored the feasibility of utilizing inherent unpaired electrons for endogenous DNP and applied it to probe buried phases in all-solid-state lithium-metal battery and the surface chemistry in carbons. I will show that wealth of information achieved by DNP on various functional materials, can place DNP-NMR as a preferable tool for materials scientists. Our findings are expected to apply to many other systems where functional materials are dominant, making DNP a more general technique.

Colloidal nanocrystals possess high surface area-to-volume ratios; as a result, many nanocrystal properties are heavily influenced by their surfaces. At these surfaces exist a complex interface between the inorganic solid (governed by the crystal structure and particle morphology) and organic ligands. The organic ligands play a key role in controlling nucleation and growth, passivating under-coordinated surface sites, and providing steric stabilization for solvent dispersibility. Depending on the particular application of the nanocrystal, the native organic ligands may then need to be removed or exchanged. We use a complement of NMR spectroscopic techniques to understand the nature of the nanocrystal surface and ligand binding. Then, using principles of inorganic coordination chemistry, we rationally enact ligand exchange reactions on these surfaces to maximize nanocrystal functionality. This talk will briefly discuss the surface chemistry of three different platforms. (1) I will discuss how we experimentally developed an atomistic picture of perovskite nanocrystal surface termination, and then used that information to better understand how common surface treatments can “heal” halide perovskite nanocrystal surfaces. (2) I will discuss how different -donating, L-type ligands were installed on the surface of metal phosphide nanocrystals, and how they affected the hydrogen evolving ability of these electrocatalysts. (3) I will discuss a new strategy for thermally activating metal carbide nanocrystal CO2 reduction catalysts using labile ligands that decompose at significantly lower temperatures than the native ligands. This circumvents issues commonly encountered with high-temperature thermolysis (coking) or acid treatments (etching, poisoning) that are used to activate nanocrystal catalysts.

The development of advanced photovoltaic devices, including those that might overcome the single junction efficiency limit, as well as the development of new materials, all rely on advanced characterization methods. Among all the existing methods optically based ones are very well adapted to quantitatively probe optoelectronic properties at any stage. We here present the use of multidimensional imaging techniques that record spatially, spectrally and time resolved luminescence images. We will discuss the benefits (and challenges) of looking into energy conversion systems from high dimensions perspective and those of dimensional reduction for improved intelligibility through some examples, mostly drawn from halide perovskite materials and device. These examples will help visit questions related to efficient transport and conversion in solar cells, as well as questions related to chemical and operational stability of the devices.

This lecture presents an overview on major research work of the Fellow’s group in the areas of polymer nanoparticles for drug delivery, control of protein adsorption on materials surfaces and protein nanofibers. In addition, the new excellence graduate school (Research Training Group) RTG 2723: Materials‐Microbe‐Microenvironments: Antimicrobial biomaterials with tailored structures and properties (M‐M‐M) funded by the German Science Foundation will be introduced. Polymer nanoparticles (PNP) became recently exceedingly popular through novel vaccination technologies but have also major potential for fighting inflammation and cancer. These drug release properties of the PNP depend on their structure. Yet, the literature reports little about the structure and the properties of most PNPs, except the chemical composition. The PNP’s crystallinity, thermal and mechanical properties are frequently ignored, even though they may play a key role in the drug delivery properties of the PNPs. Protein adsorption on biomaterials is the first process after implantation and determines much of the fate of the biomaterial, such as cell adhesion, blood coagulation or infection at the implant site. Despite decades of research, only rules of thumb exist to predict protein adsorption behavior. We present nanotechnological approaches to control protein adsorption using nanostructured semicrystalline polymers and crystal facets of TiO2. Selfassembled protein nanofibers consisting of one or more proteins, potentially allow to tailor the properties of biomaterials interfaces and to create bone mimetic structures. Finally, the new DFG‐RTG 2723: Materials‐Microbe‐Microenvironments: Antimicrobial biomaterials with tailored structures and properties (M‐M‐M) in Jena will be introduced. The aim of the RTG is to provide excellent training for approximately 40 international doctoral researchers in antimicrobial biomaterials in interdisciplinary tandem projects, connecting materials science and medical science. The RTG pursues a new strategy by developing antibiotic free biomaterials, where the antimicrobial action is based mainly on physical principles. The new RTG offers ample opportunity for fruitful cooperation and exchange with leading research institutions in Israel.

This colloquium will be divided into two applications parts, dealing with synthesis of supported molecular catalysts and solid catalysts for photoprotection. In the first of these areas, we describe a mechanical approach for stabilizing supported weakly interacting active sites (i.e. those that interact non-covalently with the support) against aggregation and coalescence. We use silica as a prototypical example of a support, and an iridium pair-site catalyst incorporating bridging calixarene ligands as an active site. Atomic-resolution imaging of the Ir centers before and after ethylene-hydrogenation catalysis show the metals resisted aggregation and deactivation, remaining atomically dispersed and accessible for catalysis. When active sites are located at unconfined environments, the rate constants for ethylene hydrogenation are markedly lower compared with confining external-surface pockets [1], in line with prior observations of similar effects in olefin epoxidation catalysis [2,3]. Altogether, these examples represent new opportunities for enhancing reactivity on surfaces by synthetically controlling mechanical features of active site catalyst environments. In the second of these areas, reactive oxygen species (ROS) are associated with several human health pathologies and are invoked in the degradation of natural ecosystems as well as building materials that are used in modern infrastructure (e.g., paints and coatings, polymers, etc). Natural antioxidants such as vitamin E function as stoichiometric reductants (i.e. reaction with ROS synthesizes rancid oils). While enzymes such as superoxide dismutase working in tandem with catalase decompose decompose ROS to H2O and O2 through H2O2 as an intermediate, these enzymes are fragile and costly. Other non-stoichiometric commercial antioxidants that degrade ROS include hindered amine light stabilizers (HALS). Here, we demonstrate that cerium carbonate acts as a degradation catalyst for photogenerated ROS, and describe the performance and characterization of this new catalyst using X-ray photoelectron spectroscopy, and in comparison with HALS and stoichiometric reductants. Our results demonstrate catalytic antioxidant activity of cerium carbonate when dispersed in polymethylmethacrylate polymer. FTIR data demonstrate that a dispersion of 2 wt. % cerium carbonate within the polymer essentially stops degradation by photogenerated ROS, which otherwise cause oxidation of the polymer backbone, in the control polymer lacking cerium carbonate. Experiments with methylene blue dye in aqueous solution demonstrate that cerium carbonate decreases the rate of ROS degradation of dye, in the presence of UV irradiation and air by 16 fold. These effects become even more pronounced (over 600 fold decrease in rate of ROS dye degradation) when cerium carbonate is paired with a photoactive metal oxide. The mechanism involved in this latter case crudely mimics the enzyme tandem sequence referred to above. [1] C. Schöttle, E. Guan, A. Okrut, N. A. Grosso-Giordano, A. Palermo, A. Solovyov, B. C. Gates, A. Katz*, Journal of the American Chemical Society, J. Am. Chem. Soc. 2019, 141, 4010-4015. [2] N. A. Grosso-Giordano, C. Schroeder, A. Okrut, A. Solovyov, C. Schottle, W. Chasse, N. Marinkoyic, H. Koller, S. I. Zones, A. Katz, Journal of the American Chemical Society 2018, 140, 4956-4960. [3] N. A. Grosso-Giordano, A. S. Hoffman, A. Boubnov, D. W. Small, S. R. Bare, S. I. Zones, A. Katz, Journal of the American Chemical Society 2019, 141, 7090-7106. [4] M. K. Mishra, J. Callejas, M. Pacholski, J. Ciston, A. Okrut, A. Van Dyk, D. Barton, J. C. Bohling, A. Katz, ACS Applied Nano Materials 2021, 4, 11, 11590-11600.

https://weizmann.zoom.us/j/95467631640?pwd=MHZBNThNQlRUeU1CM29kQXZZcGxOdz09 password:864419 Solid oxide fuel cells (SOFCs), especially proton conducting (PC)-based, and electrolyzes (SOEs), operating above 250°C, demonstrate rapid electrode kinetics, but are limited in their long term stability due to thermal stresses related to on/off cycling. Thermal stress could be reduced dramatically, for PC-SOFCs devices operating in the temperature range of 150-250°C, which would still benefit from fast electrode kinetics and would not require Pt-containing catalytic electrodes. However, a proton-conducting ceramic electrolyte, operating below 250°C hasn’t been identified yet. In this work I investigated the synthesis, preparation protocols and properties of La(OH)_3 and La_2 Ce_2 O_7 (LCO50) powder and ceramics to explore their suitability as proton conductors. Preparation of appropriate pellet samples of La(OH)_3 from the synthesized powder requires (i) elimination of the presence of carbonate oxides followed by (ii) hydration of the remaining La2O3 in boiling deionized water. Room temperature compaction of these powders into solid pellet samples requires prolonged dwell uniaxial pressure. Although the primarily protonic conductivity of the compacted sample reached only 3·10-11 S/cm at 90°C and is insufficient for practical applications; the grain boundaries are apparently not blocking, making it attractive to look for dopants that may potentially enhance the low temperature conductivity. Nominally anhydrous LCO50 has an unexpectedly high conductivity 10-11 S/cm at 110 °C, which is probably due to oxygen vacancies. LCO50 undergoes hydration with a large lattice expansion, which combined with low hydration enthalpy (5.2 kJ/mol) restricted compact crack-free sample. Hydration of LCO50 by 7.5% of the maximum possible showed to have non-blocking grain boundaries, and increases the conductivity by an order of magnitude, which has to be attributed to protonic conduction. Findings describe in this work, point that both investigated materials are promising candidates for further studies as proton conductors.

Catalysis is a key technology, since it allows for increased levels of selectivity and efficacy of chemical transformations. While significant progress can be made by rational design or engineered step-by-step improvements, many pressing challenges in the field require the discovery of new and formerly unexpected results. Arguably, the question “How to discover?” is at the heart of the scientific process. In this talk, (smart) screening strategies for accelerated discovery and improved reproducibility will be presented, together with new photocatalytic transformations. In addition, two other exciting areas will be addressed: N-heterocyclic carbenes (NHCs) are powerful ligands in catalysis due to their strong electron-donating properties and their ability to form very stable bonds to transition metals. In addition, they can stabilize and modify nanoparticles or flat metals surfaces, outperforming established phosphine or thiol ligands regarding structural flexibility, electron-donating properties and stability. Current research is highly interdisciplinary and focusses on the basic understanding of the binding mode, mobility and the elucidation of the impact on the surface properties. Exciting applications in materials science, heterogeneous catalysts and beyond are within reach. Biological membranes and their constituents are some of the most important and fundamental building blocks of life. However, their exact role in many essential cellular processes as well as in the development of diseases such as cancer or Alzheimer's is still not very well understood. Thus, we design, synthesize and evaluate imidazolium-based lipid analogs that can integrate into biological membranes and can be used as probes for live cell imaging or to manipulate membranes.

Charge transfer and transport processes through molecular interfaces are ubiquitous and of a crucial role in determining functionality of biological systems and in enabling energy conversion applications. We study computationally such processes to understand structure-function relationships at the molecular level. We will discuss studies in the following two primary fields: (1) Photovoltaic and charge transfer properties of organic semiconductors materials. (2) Charge transport through voltage-biased molecular scale bridges. Importantly we establish predictive computational scheme that addresses key challenges. Our studies are employed in conjunction with experimental efforts to design materials and applications that control and tune relevant physical properties

Molecular crystals are supramolecules “par excellence"1 as they are macroscopic objects composed by millions of molecules periodically disposed and held together by non-covalent interactions with specific physico-chemical properties dictated by their architectures. This offers a vibrant solid-state chemistry playground to build organic solids with tailored functionalities, such as novel luminescent materials,2 solid-state molecular machines,3 and multicomponent crystals with complex topologies.4 The inherent dynamic nature of the weak intermolecular forces that are driving organic crystals self-assembly is also conferring adaptive responsiveness, e.g., mechanical reconfiguration and shape-memory effect, to this class of materials making them ideal building blocks for the design and synthesis of multifunctional crystalline systems that can be exploited as actuators, flexible single-crystalline optoelectronic devices, and self-healing materials.5

The studies of magnetic atoms adsorbed on non-magnetic surfaces provide a fundamental insights into the quantum many-body phenomena at the nanoscale. They imprint non-trivial signatures in STM measurements, and can serve as a prototype for potential applications in quantum information technology. Our work aims at the investigation of the electronic structure, spin and orbital magnetic character for the Co adatom on the top of Cu(100) surface. We make use of DFT combined with exact diagonalization of the multi-orbital Anderson impurity model, including the spin-orbit coupling. For the Co atom d-shell occupation nd=8, a singlet many-body ground state and Kondo resonance are found, when the spin-orbit coupling is included in the calculations. The differential conductance is evaluated in a good agreement with the STM measurements. This comparison is the most direct way to demonstrate the validity of our theoretical approximation. Our results illustrate the very essential role which the spin-orbit coupling is playing in a formation of Kondo singlet for the multi-orbital impurity in low dimensions.

Self-assembly and self-organization are two big challenges in the natural sciences. What are the rules governing the emergence of greater structures from unassuming elements? Does statistical-mechanics restrict their complexity? Biochemical processes can shape highly specific structures and function on the macro-scale using only molecular information. Although stereochemistry has been a central focus of molecular sciences since Pasteur, its synthetic province has been restricted to the nanometric scale. In my talk, I will describe how to propagate molecular information to self-assemble free-form architectures on the micron-scale and beyond. These architectures are a thousand times greater than their constituent molecules yet have a preprogrammed geometry and chirality. I will then show how to animate such synthetic microstructures into bacteria-like micro-swimmers. Previous artificial microswimmers relied on an external chemical fuel to drive their propulsion which restricted their operational concentration as they competed locally over fuel. I will demonstrate how to use material science and physical chemistry to self-assemble fuel-free micro-swimmers that are driven solely by light. The fuel independence allows the swimmers to stay active even at high densities, where they form turbulent flow structures (previously seen in living fluids), and cooperate to perform a greater task.

Zoom Link: https://weizmann.zoom.us/j/93495966390?pwd=T3hDNXY1WFh6bFpIbDh3OEFxZlcwZz09 The fibre-matrix interface plays a vital role in the overall mechanical behaviour of a fibre-reinforced composite, but the classical approach to improving the interface through chemical sizing is limited by material properties. Achieving a simultaneous improvement in strength and toughness in a composite is a particular challenge since these properties are mutually exclusive, and the chemical modification of the interface often results in one property being improved at the expense of the other. In contrast, the geometrical modification of the fibre-matrix interface to allow for mechanisms such as mechanical interlocking of components is a promising approach to resolving this challenge. This study explores a novel type of topographical obstacle – polymer droplets at the fibre-matrix interface. Discrete epoxy droplets are deposited onto glass fibres and embedded in an epoxy matrix to form model composites. The effect of the interfacial epoxy droplets is investigated using single fibre experiments.

Zoom Link: https://weizmann.zoom.us/j/99290579488?pwd=cUIyV05SMUQ0VDErNUtma1RTL3BIQT09 In the last decade, halide perovskites (HaPs) have developed as promising new materials for a wide range of optoelectronic applications, notably solar energy conversion. Although their technology has advanced rapidly towards high solar energy conversion efficiency and advantageous optoelectronic properties, many of their properties are still largely unknown from a basic scientific standpoint. Due to the highly dynamical nature of HaPs, one of the main avenues for basic science research is the use of molecular dynamics (MD) simulations, which provide a full atomistic picture of those materials. One of the main limiting factors for such analysis is the time scale of the MD simulation. Because of the complexity of the HaP system, classical force field approaches do not yield satisfactory results and the most widely used force calculation approach is based on first-principles, namely on density functional theory (DFT). In recent years, a new type of force calculation approach has emerged, which is machine learned force fields (MLFF). These methods are based on machine learning (ML) algorithms. Their wide spread use is enabled by the ever-increasing computational power and by the availability of large-scale shared repositories of scientific data. Here, we have applied one MLFF algorithm, known as domain machine learning (GDML). After training a MLFF based on the GDML model, we observed that the MLFF fails in a dynamical setting while still showing low testing error. This has been found to be due to lack of full coverage of the simulation phase space. To address this issue, we have suggested the hybrid temperature ensemble (HTE) approach, where we create rare events that are training samples on the edge of the phase space. We achieve this by combing MD trajectories from a range of temperatures to a single dataset. The MLFF model, trained on the HTE dataset, showed increasing accuracy during the training process, while being dynamically stable for a long duration of MD simulation. The trained MLFF model also exhibited high accuracy for long-term simulations, showing remaining errors of the same magnitude of inherent errors in DFT calculation.

Methodologies that rely on the addition and removal of molecular hydrogen from organic compounds are one of the most oft-employed transformations in modern organic chemistry, representing a highly relevant tactic in synthesis. Despite their overall simplicity, organic chemists are still pursuing sustainable and scalable processes for such transformations. In this regard, electrochemical techniques have long been heralded for their innate sustainability as efficient methods to perform redox reactions. In our first report, we discovered a new oxidative electrochemical process for the a,b-desaturation of carbonyl functionalities. The described desaturation method introduces a direct pathway to desaturated ketones, esters, lactams and aldehydes simply from the corresponding enol silanes/phosphates, and electricity as the primary reagent. This electrochemically driven desaturation exhibits high functional group tolerance, is easily scalable (1–100 g), and can be predictably implemented into synthetic pathways using experimentally or computationally derived NMR shifts. Our second report demonstrated the reductive electrochemical cobalt-hydride generation for synthetic organic applications inspired by the well-established cobalt-catalyzed hydrogen evolution chemistry. We have developed a silane- and peroxide-free electrochemical cobalthydride generation for formal hydrogen atom transfer reactions reliant on the combination of a simple proton source and electricity as the hydride surrogate. Thus, a versatile range of tunable reactivities involving alkenes and alkynes can be realized with unmatched efficiency and chemoselectivity, such as isomerization, selective E/Z alkyne reduction, hydroarylation, hydropyridination, strained ring expansion, and hydro-Giese.

Zoom Link: https://weizmann.zoom.us/j/95952232097?pwd=OW9SL2JlNkNYQVJ1cW5FT05HcEh2QT09 The optimally-tuned range separated hybrid (OT-RSH) functional is a non-empirical method within density functional theory, which is known to yield accurate fundamental gaps for a variety of systems. Here we extend its applicability to magnetic resonance parameters, enhance its accuracy by designing OT-RSH based double-hybrid functionals, and increase its precision for solid-state calculations by designing and generating RSH pseudopotentials.

Zoom Link: https://weizmann.zoom.us/j/97777492731?pwd=YXZDR0lqYUtMbHVidUlIWkl2TGxjdz09 Protein-metal interactions play an important regulatory role in the modulation of protein folding and in enabling the “correct” biological function. In material science, protein self-assembly and metal-protein interaction have been utilized for the generation of multifunctional supramolecular structures beneficial for bio-oriented applications, including biosensing, drug delivery, antibacterial activity, and many more. Even though, the nature and the mechanisms of metal-protein interaction have been extensively studied and utilized for the functionalization of protein-based materials, mainly with metal-based nanoparticles, our understanding of how metals shape protein folds, the inter-and intramolecular interactions, the associative behavior, and evolve material characteristics of protein constructs, is limited. To address these highly challenging scientific questions, I have explored the self-assembling behavior of silk fibroin protein and its’ interaction with metal nanoparticles for the formation of multifunctional composites. The central goal of my research was to explore the full potential of metal nanoparticles (NP), in particular, copper oxide (CuO) to modify the self-assembly pathway of fiber-forming protein- silk fibroin. CuO NP has been chosen as a candidate for this study, due to its versatile properties and bio-relevant functionalities applicable for sensing, antibacterial function, and capability to regulate cellular activity. Thus, to address this challenge I first focused on the understanding of metal NP-induced structural transformations in natively folded protein and on probing whether these structural changes can be artificially imposed on the assembled, β-sheet rich protein complexes. My experimental results showed that CuO NPs are indeed capable of template the assembly of natively folded silk fibroin, on the one hand, and on the other hand, exhibited variations in NPs-silk fiber interaction when added at the post-synthetic stage. Yet, the fundamental questions of how RSF-CuO NPs self-assembly occurs remain to be addressed. The exploration of biomaterial applications for silks is only a relatively recent advance; therefore, the future for this family of structural proteins appears promising.

Zoom: https://weizmann.zoom.us/j/95703489711?pwd=Tyt5cU1tV2YrMFhYUytBU001bm4yQT09 Viable, global-scale photoelectrochemical energy conversion of cheap, abundant resources such as water into chemical fuels (“solar fuels”) depends on the progress of semiconducting light-absorbers with good carrier transport properties, suitable band edge positions, and stability in direct-semiconductor/electrolyte junctions. Investigations concentrated mainly on metal-oxides that offer good chemical stability yet suffer from poor charge transport than non-oxide semiconductors (e.g., Si, GaAs). Fortunately, only a fraction of the possible ternary and quaternary combinations (together ~ 105 – 106 combinations) were studied, making it likely that the best materials are still awaiting discovery. Unfortunately, designing controlled synthesis routes of single-phase oxides with low defects concentration will become more difficult as the number of elements increases; and 2) there are currently no robust and proven strategies for identifying promising multi-elemental systems. These challenges demand initial focusing on synthesis parameters of novel non-equilibrium synthesis approaches rather than chemical composition parameters by high-throughput combinatorial investigations of synthesis-parameter spaces. This would open new avenues for stabilizing metastable materials, discovering new chemical spaces, and obtaining light-absorbers with enhanced properties to study their physical working mechanisms in photoelectrochemical energy conversion. I will introduce an approach to exploring non-equilibrium synthesis-parameter spaces by forming gradients in synthesis-parameters without modifying composition-parameters, utilizing two non-equilibrium synthesis components: pulsed laser deposition and rapid radiative-heating. Their combination enables reproducible, high-throughput combinatorial synthesis, resulting in high-resolution observation and analysis. Even minor changes in synthesis can impact significantly material properties, physical working mechanisms, and performances, as demonstrated by studies of the relationship between synthesis conditions, crystal structures of α-SnWO4, and properties over a range of thicknesses of CuBi2O4, both emerging light-absorbers for photoelectrochemical water-splitting that were used as model multinary oxides.

https://weizmann.zoom.us/j/97328767376?pwd=MkZoQ0hmbVVRank0bzkxbGpqSUdYUT09 passcode: 891716 Lithium-ion batteries with liquid electrolytes are commonly employed for powering portable electronic devices. To expand the range of applications where Li ions batteries can be used (e.g., electric transportation), solid electrolytes are considered as a safer alternative to the liquid electrolytes and they may enable use of lithium metal anodes. In this study we focused on composite solid electrolytes which are based on solid polymer (Polyethylene Oxide) and ceramic particles (Li1.5Al0.5Ge1.5P3O12, LAGP). Previous studies revealed that the highest ionic conduction path in the composites is through the interface polymer - ceramic interface. However, the chemical nature of the interface and the reason for its higher conductivity remains unclear. We aim to gain molecular - atomic level insight into the nature of the polymer - ceramic interface from solid state NMR spectroscopy. Here, I will present the development of a solid - state NMR approach that can potentially be used to selectively probe the interface. To gain sensitivity and selectivity Dynamic Nuclear Polarization (DNP), a process in which high polarization from unpaired electrons is transferred to surrounding nuclear spins will be employed. Several metal ion dopants were tested for their DNP performance in LAGP powder, and Mn2+ ions were further examined in their efficacy in the composite electrolyte. The approach was tested for selectively enhancing the NMR signal of the PEO - LAGP interface. Electrochemical characterization and in - depth solid state NMR studies provided insight into the performance of the composite and degradation processes in the composite.

Zoom Link: https://weizmann.zoom.us/j/96430042316?pwd=cjJwdFUrSEE5VnU4eVNuY08wZ1F3QT09 Raman spectroscopy is used as a primary non-destructive tool for characterization of strain in thin films. It is based on the concept of the mode Grüneisen parameter, which is the ratio between the relative change in the energy of a given vibrational mode and the relative change in the unit cell volume. It has been recently reported (Kraynis et al.) that under biaxial strain, doped CeO2-films exhibit values of the mode Grüneisen parameter, which are up to 40% smaller than the bulk literature value. Doped CeO2-films are strongly anelastic, posing a question on the relation between Raman scattering frequency and anelastic strain. This work describes the way to separate anelastic and elastic contributions to the Grüneisen parameter of doped ceria thin films and show that this concept remains applicable, if only the elastic part of the strain must be taken into account. As a reference, I deposited a purely elastic yittria thin film by sputter deposition and calculated its Grüneisen parameter in a similar way. The experimental and literature values of the yittria Grüneisen parameter were found compatible, confirming that for purely elastic strain, Grüneisen parameter concept is fully applicable.

With the growing complexity of functional materials and chemical systems, we often nd ourselves limited in our ability to fully represent the set of descriptors of a chemical system. In complex chemical systems, nding a complete crystallographic model that folds all the interatomic correlations using a small set of structural descriptors may not always be feasible or practical. Alternatively, one can take a data-driven approach and measure the relative changes in structural or chemical features (e.g, structural correlations, oxidation states). An experimental data-driven approach does not require complete models and enjoys the rapidly evolving machine-learning tool-set, which excel at classifying relational datasets and, if also labelled by an observed property, can provide predictive power that links system's descriptors with observed properties. I will focus on two types of complexities: (1) Hierarchical complexity, in which dierent types of structural or chemical correlations change change with the probed correlation length. For example, in ferroic materials dierent prop- erties (e.g., mechanical, dielectric, optoelectronic) may depend dierently on short- and long- range structural correlations. In multi-component alloys local chemical correlations (random- distribution, ordering, clustering) can aect corrosion and plasticity, but altogether show a single average structural phase. Since selected materials' properties depend on correlations at a specic hierarchical level, it is important to be able to isolate those from one another. (2) Evolutionary complexity, where the order changes over space and/or time. Nucleation, crys- tal growth, intercalation - are examples for processes that involve evolutionary complexity and can also be found in batteries, heterogeneous catalysis and photovoltaics. Isolating and track- ing order-related correlations in heterogeneous kinetically-stabilized or dynamically changing systems is, therefore, important for their more complete understanding, design and control. Total scattering and Pair Distribution Function (PDF) analysis are key methods for unfolding structural correlations at dierent correlation lengths. Using 4D-STEM to generate nm-resolution spatially-resolved electron-PDF data taken from hot-rolled Ni-laminated bulk-metallic-glass [1], I demonstrate how both hierarchical and evolutionary complexity can be uncovered and studied. Par- tially assisted with a machine-learning classication toolbox, we show how dierent aspects of the structural and chemical order, such as chemical-short-range-order, can be directly visualized as a function of position. In a dierent example [2] I show how an evolutionary complex systems can be manipulated to achieve a desired chemical state. In this example we demonstrate an active reaction control of Cu redox state from real-time feedback from in-situ synchrotron measurements. While complexity can lead to a lack of control over a chemical system, it is essentially adding tuning-knobs that, once isolated, understood and controlled, can unlock new materials with desired functionalities. [1] Y. Rakita, et al., Mapping Structural Heterogeneity at the Nanoscale with Scanning Nano-structure Electron Mi- croscopy (SNEM), arXiv:2110.03589 (2021). [2] Y. Rakita, et al., Active reaction control of Cu redox state based on real-time feedback from in situ synchrotron measurements, JACS 142, 18758 (2020). DOI: 10.1021/jacs.0c09418. 1

baradhn@is.mpg.de In the quest for improving sustainability of earth’s resources, discovery of new catalysts is a press-ing issue. There are several reasons for that, among which are: First, presently the most efficient and stable catalysts for the chemical processes that we use to transform raw resources into products with the desired functions (materials or energy type), contain expensive and non-abundant elements such as Pt, Ir, and Ru. This explains the efforts to find abundant, accessible, low-cost, stable alternatives that will yield functionality comparable to exist-ing catalysts. For example, for water splitting, many new materials with different compositions have shown promising results as catalysts. However, they are mostly prepared by wet chemical synthesis, which results in chemical waste and can be too slow for industrial use. Second, the morphology of the materials is important, because it affects their catalytic properties as higher surface areas yield more catalytic active sites, surface energetics change, leading to improved reaction rates, and other differences that affect catalytic activity. These reasons emphasize the motivation to accelerate the process of finding new materials with varying nanostructures and optimized functionality, by sys-tematic exploration of several parameter spaces. Glancing angle deposition (GLAD) is a physical vapor deposition (PVD) shadow growth technique where the substrate is positioned at an oblique angle to the vapor source and can be manipulated with regard to substrate tilt angle and rotation, during the deposition. The thin films obtained by GLAD have unique nano-structures, which depend on ballistic shadowing of the substrate, and are formed as nano-structured films, leading to 3D nano-fabrication. I will present the first original results I obtained of using GLAD to form different types of material compositions and nanostructures as functional catalysts for sustainable resources. Nano-scale mor-phology and material composition are varied simultaneously using an adapted shadow growth GLAD system,[1] which eliminates the commonly used wet chemical steps for nanostructure synthe-sis. In a well-controlled one-step growth, I quickly and directly attain a large number of different nano-columnar structures, including nanorods, nano-barcodes, and nano-zigzags, with varying ma-terial compositions, on a single large-area substrate. GLAD also serves to form nanoporous ultra-thin mesh structures, in a novel dry synthesis method.[2] Both nanostructure types were studied for their electrocatalytic performance in the O2 evolution as well as CH3OH oxidation reactions and show high activity and stability. The insights I gained, show a dependence of catalytic activity on composition and nanostructuring, which the standard experimental techniques cannot achieve or explore, thus illustrating the importance and impact that GLAD has, and will have, on developing sustainable catalysts. [1] H.-N. Barad, M. Alarcón-Correa, G. Salinas, E. Oren, F. Peter, A. Kuhn, P. Fischer, Mater. To-day 2021, In Press, DOI 10.1016/j.mattod.2021.06.001. [2] H. Kwon, H.-N. Barad, A. R. S. Olaya, M. Alarcon-Correa, K. Hahn, G. Richter, G. Wittstock, P. Fischer, ArXiv211105608 Phys. 2021.

Zoom Link: https://weizmann.zoom.us/j/91582672181?pwd=WFR1NVhKZGtra2w1WG9CcGFLSGU0Zz09 Non-stoichiometric oxides are a group of materials that are extremely popular in the energy storage and conversion industry. Their functionality relies heavily on point defects and their various properties show significant dependency on point defect type and concentration. This work deals with three such properties: mechanical, electromechanical and electro-chemo-mechanical while looking into two case study materials: 1. Acceptor-doped proton conducting BaZrO3, a promising electrolyte for protonic ceramic fuel cells as it combines high bulk proton conductivity with good chemical stability. The protonic conductivity is achieved by dissociative water incorporation into oxygen vacancies formed by acceptor dopants on Zr4+ sites. Doping was found to cause linear decrease in elastic modulus with increasing dopant concentration while the size of the dopant was proved to be a key factor. Water incorporation into the vacancies decreases the moduli even further. An unexpectedly large strain electrostriction coefficient of ≈ 5·10-16 m2/V2 was observed which makes BaZrO3 the first non-classical electrostrictor with a perovskite structure. The electromechanical response was observed to follow elastic moduli trend with respect to dopant size, giving a clear indication that electrostrictive response is related to point defect induced lattice distortions. 2. Acceptor doped oxygen conducting CeO2. The first known all solid-state electro-chemo-mechanical actuators operating at room temperature were demonstrated. These devices are based on nanocrystalline (Ti-oxide/Ce0.8Gd0.2O1.9) and (V-oxide/Ce0.8Gd0.2O1.9) composite layers. Under applied bias these composites undergo an electrochemical reaction generating change in specific volume and, thereby, mechanical work. The nanocrystalline composites are the key part of these devices and they are specifically designed to provide the fastest oxygen ion diffusion coefficient observed in a solid at room temperature. This achievement paves a way to a new field of studies: all solid-state chemotronics. The findings presented in this work link together three properties of non-stoichiometric ion conducting oxides: elastic deformation, electromechanical response and solid-state electrochemistry.

Single layers of transition metal dichalcogenides are semiconducting 2D materials which present unique electronic, excitonic and spin properties. Heterostructures composed of these materials show highly intriguing excited-state phenomena, along with a large degree of atomistic and structural tunability stemming from the underlying quantum selection rules dominating these phenomena. A predictive understanding of the effect of structural complexity on the nature of excited-state properties and interaction dynamics is crucial in order to design efficient devices for various applications, within the fields of photovoltaics, photocatalytics, optoelectronics, spintronics, and material-based quantum computing. In this research, we propose a study of the electronic and excitonic properties in heterostructures based on layered transition metal dichalcogenides and the role of structural complexities in their time-resolved relaxation mechanisms. For this, we will analyze decay processes induced by excitonic interactions with lattice vibrations, as well as other excitons and charged particles in the crystals. We will utilize predictive, Green’s-function based ab-initio methods implemented through advanced software and apply highly advanced computations using high-performance computing clusters worldwide. We will develop computational models based on these predictive approaches and on our findings to study the underlying mechanisms dominating the involved excitation processes and the light-matter interactions leading to them. Our research will be constantly driven and validated by collaborations with relevant experimental research.

Zoom Link: https://weizmann.zoom.us/j/95894806650?pwd=c21JSFRhcUZaalROaUlBWnh4T25yZz09 Low-dimensional materials, such as 2D monolayers, 1D nanowires, and 0D quantum dots and molecules, are rich with new phenomena. The reduced dimensionality, strong interactions, and topological effects lead to new emergent degrees of freedom of fundamental interest and promise for future applications, such as energy-efficient computation and quantum information. Thermal transport, which is sensitive to all energy-carrying degrees of freedom and their interactions, provides a discriminating probe to study these materials and identify their emergent excitations. However, thermal measurement in low dimensions is dominated by the lattice, requiring an approach to isolate the electronic contribution. In this talk, I will discuss how the measurement of nonlocal voltage fluctuations in a multiterminal device can reveal the electronic heat transported across a low-dimensional bridge. We use 2D graphene as an electronic noise thermometer, demonstrating quantitative electronic thermal conductance measurement over a wide temperature range in an array of dimensionalities: 2D graphene, 1D nanotubes, 0D localized electron chains, and 3D, microscale bulk materials. I will discuss ongoing work revealing electron hydrodynamics, interaction-mediated plasmon hopping, spin waves in a magnetic insulator, and a crossover from phonon to spin transport in a bulk spin liquid candidate material.

London dispersion (LD) interactions, the attractive part of the van-der-Waals interaction1,2 hold somewhat of a unique position in the chemical world. Although their role in influencing macroscopic phenomena (such as the higher boiling points of larger alkanes) is well recognized, they are usually overlooked when discussing molecular phenomena. Substituents in reactions are generally considered as a source of “steric hindrance” and not as “steric attractors”, better termed dispersion energy donors (DEDs). As such, their influence on reaction outcomes was quantified and presented by classic steric factors such as the A-value. We have shown, using computational quantum mechanical tools, that these well recognized steric factors have also an attractive LD component that balance part of the steric repulsion. By focusing on the LD component we can explain various non-intuitive trends between substituents, such as the inconsistency between the size of the halogens and their A-values.3 In addition, a systematic analysis of both the steric and dispersion interactions of the same molecules allows us to quantify the relative weights of the two effects and form a new DED scale.4 Such corrected steric and LD factors could later be applied to explore the role of LD interactions also in other reactions. Our computations show that LD interactions have a significant influence on the overall relative stabilities and energetics in cyclohexane chair conformers, and also in related concerted reactions, and must not be ignored in reaction design.    Bibliography (1) Eisenschitz, R.; London, F. Z. Phys. 1930, 60, 491–527. (2) London, F. Trans. Faraday Soc. 1937, 33, 8–26. (3) Solel, E.; Ruth, M.; Schreiner, P. R. London Dispersion Helps Refine Steric A-Values: The Halogens. J. Org. Chem. 2021, 86 (11), 7701–7713. (4) Solel, E.; Ruth, M.; Schreiner, P. R. London Dispersion Helps Refine Steric A‑Values: Dispersion Energy Donor Scales. J. Am. Chem. Soc. 2021, Accepted.

Metal halide perovskites (MHPs) have re-emerged as exceptional semiconductor materials for photovoltaics and optoelectronics, gaining tremendous attention in the fields of materials and energy harvesting over the past decade. Their unique properties, alongside their relatively cheap and easy production, make them excellent candidates as materials for the next-generation optoelectronic technologies. Besides their technological advantage, their soft ionic lattice and anharmonic potential, that are part of the underlying reasons for their unusual and outstanding performance, challenge the well-established models of classical semiconductor physics and provoke many scientific research opportunities and questions. In order to intrinsically study these outstanding behaviors, a simple system is requires, diminishing complexities that can arise when examining the popularly studied polycrystalline thin films that contain multiple defects, mainly grain boundaries. Over the past decade, our group has been developing and mastering the surface-guided growth of horizontal semiconductor NWs, which can be employed to grow arrays of epitaxial single crystal MHP NWs. These NWs offer a unique opportunity as a simple model-system for investigating the intrinsic properties of MHPs, due to their single crystal nature and quasi one-dimensional structure. These are especially suitable for the investigation of how lattice strain affects the materials’ properties, considering their inherent heteroepitaxial strain. The aim of this PhD work was to gain insight on the growth of surface-guided CsPbBr3 NWs, as a representative of the MHP family, and study the effect of epitaxial strain on their structure and properties. To achieve this goal, we first developed the crystal growth of the surface-guided CsPbBr3 NWs on sapphire, by a few different vapor-phase methods. We inspected their growth in situ using simple optical microscopy to try to learn how these unique materials grow. These were followed by integration of the NWs into nanodevices in order to examine their optoelectronic properties, with a special emphasis on the influence of strain on their performance. We finally exemplified a high-throughput study using an automated optical system that can probe many NWs in a short amount of time, to develop a charge-carrier behavior model based on a large amount of data. Studying the epitaxially strained surface-guided CsPbBr3 NWs provides important insight into the crystal growth and optoelectronic properties of MHPs

The fact that many crystals are not in equilibrium is quite obvious and not very surprising. Yet, this often complicates our attempts to understand some of their most fundamental properties, such as for instance, their overall morphology. To further add to this complexity, non-equilibrium properties are nowadays studied in crystals made out of building blocks that consume energy and actively propel (i.e., active matter). Despite some complications that exist when trying to make analogies between the behavior of bulk crystals and their nanoscale analogs, the latter offer many advantages when studying kinetic aspects of crystal formation, in both “conventional” as well as “active” crystals. In my talk I will present two different cases where nanocrystals are used in order to shed light on some of these aspects. The first story dates all the way back to the 19th century and the seminal work by Louis Pasteur on crystals that exhibit chiral macroscopic shapes when made out of chiral building blocks. Using a model system of tellurium nanocrystals, I was able to show that the reason for chiral shape formation in crystals composed of chiral building blocks might not always be as trivial as expected. In the second part of the talk, I will present the first steps I took on an ongoing journey to understand the diffusion of extremely small (sub 10 nm) chemically propelled nanocrystals. This is meant to pave the way to ultimately use them as building blocks for non-equilibrium active crystalline matter.

Phosphine carboxylate, H2PCO2-, was prepared and isolated for the first time. This heavier analogue of carbamate was found to be a carbon dioxide adduct on the edge of stability. The mechanism of phosphine carboxylate formation was found to proceed by a chain reaction that alternates between the acidified HPCO and the newly found cyclic hemi-acidified H(PCO)2-. This mechanism sheds light on the electrophilic reactivity of PCO- and similar molecules as well as their acid-base reactivity. Acidification of phosphine carboxylate forms phosphine carboxylic acid, an analogue of carbamic and carbonic acids that has surprising kinetic stability. Nucleophilic reactivity of phosphine carboxylate forms stabilized organic-soluble esters that may be used as building blocks in organic synthesis

Zoom Link: https://weizmann.zoom.us/j/96221353497?pwd=OWppT1ExY1Ewcm8zSGt4MzcvNWNiUT09 The central aim of the research is to understand how the molecular and nanoscale interactions between two natural biopolymers, fiber-forming protein-silk and conductive polysaccharide-pectin, shaping the physical properties of macro-scale composite material.

Zoom Lecture: https://weizmann.zoom.us/j/98819686427?pwd=algvMEJUNHdvaFppNS9xVzlTUkhYQT09 Passcode: 551107 Many functions of RNA depend on rearrangements in secondary structure that are triggered by external factors, such as protein or small molecule binding. These transitions can feature on one hand localized structural changes in base-pairs or can be presented by a change in chemical identity of e.g. a nucleo-base tautomer. We use and develop R1ρ-relaxation-dispersion NMR methods for characterizing transient structures of RNA that exist in low abundance (populations

Zoom Link: https://weizmann.zoom.us/j/97324532197?pwd=MGoxSGhJODNWQ2ZGT1p4elJjMG9lZz09 Cell-cell communication is essential for growth, development and function. Cells can communicate mechanically by responding to mechanical deformations generated by their neighbors in the extracellular matrix (ECM). The ECM is a non-linear viscoelastic material and therefore mechanical communication is expected to be frequency-dependent. In my talk, I will describe our work on the characteristics and implications of mechanical communication over the ECM.

Zoom LInk: https://weizmann.zoom.us/j/95962123886?pwd=ZWV6WkwxKzlNU00zRU1ER3JIWkg4Zz09 In this talk I will describe cutting-edge bio and nanotechnologies for engineering functional tissues and organs, focusing on the design of new biomaterials mimicking the natural microenvironment, or releasing biofactors to promote stem cell recruitment and tissue protection. In addition, I will discuss the development of patient-specific materials and 3D-printing of personalized vascularized tissues and organs. Finally, I will show a new direction in tissue engineering, where, micro and nanoelectronics are integrated within engineered tissues to form cyborg tissues and bionic organs.

Zoom LInk: https://weizmann.zoom.us/j/97917323609?pwd=OGpCVzNKWGlCSS9lbTIyS0FtN1lHUT09 Recent experiments have demonstrated that rapid rupture fronts, akin to earthquakes, mediate the transition to frictional motion. Moreover, once these dynamic rupture fronts ("laboratory earthquakes" ) are created, their singular form, dynamics and arrest are well-described by fracture mechanics. Ruptures, however, need to be created within initially rough frictional interfaces, before they are able to propagate. This is the reason that ``static friction coefficients” are not well-defined; frictional ruptures can nucleate for a wide range of applied forces. A critical open question is, therefore, how the nucleation of rupture fronts actually takes place. We experimentally demonstrate that rupture front nucleation is prefaced by slow nucleation fronts. These nucleation fronts, which are self-similar, are not described by fracture mechanics. They emerge from initially rough frictional interfaces at a well-defined stress threshold, evolve at characteristic velocity and time scales governed by stress levels, and propagate within a frictional interface to form the initial rupture from which fracture mechanics take over. These results are of fundamental importance to questions ranging from earthquake nucleation and prediction to processes governing material failure.

Zoom link: https://weizmann.zoom.us/j/94322871667?pwd=NXkvODRXWVZlbW9hSEtScHN1M0F4dz09 passcode: 870711 Neuroimaging has allowed us to map the correlations between brain activation, and external stimuli or behaviour. Yet these correlations can only hint at the function of the brain regions involved. In order to more casually investigate these relationships between brain and behaviour, we must perturb the brain, and see what changes this brings about in behaviour. I will provide a framework for doing so through covert neurofeedback. This technique allows us to perturb brain networks by reinforcing desired network states directly, through a reward orthogonal to the networks being trained. Yet a prerequisite for such a test of function and causality, is a strong hypothesis regarding the purported link between a specific network and behaviour. We must therefore also develop better behavioural tools, in order to establish such links.

Zoom Link: https://weizmann.zoom.us/j/92668474661?pwd=d01aQVZkWnhiT0NRQlFkVE5XeWRjdz09 Caveolae, the flask-shaped pits covered by caveolin-cavin coats, are abundant features of the plasma membrane of many cells. Besides appearing as single membrane indentations, caveolae are organized as superstructures in the form of rosette-like clusters. Here we propose that clustering of caveolae is driven by forces originating from the elastic energy of membrane bending deformations and membrane tension. We substantiate this mechanism by computational modeling, which recovers the unique shapes observed for the most ubiquitous caveolar clusters consisting of two, three, four and five caveolae.

Zoom Link: Zoom: https://weizmann.zoom.us/j/91742036303?pwd=cWJuOFBEZUpYU3p6bHBjUEduRllxdz09 Passcode: 771770 Electron and nuclear spins in diamond have long coherence and relaxation times at room temperature, making them a promising platform for applications such as biomedical and molecular imaging and nanoscale magnetic field sensing. While the optically-active nitrogen-vacancy (NV) defect has received a great deal of attention, the substitutional nitrogen (or P1) center also exhibits long coherence and relaxation times. These P1 centers are typically present at significantly larger concentrations (about an order magnitude larger) than NVs, allowing us to explore the role of P1-P1 interactions in mediating DNP. The system can, in principle, show DNP via the solid effect (SE), cross effect (CE) and Overhauser effect (OE) depending on the P1 concentration and the field. Here, we show enhancement of natural abundance 13C nuclei found within the diamond, using the unpaired electron of the P1 center (concentration 110-130 ppm) in particles with a 15-25 μm diameter, under static conditions at room temperature and 3.4 T. We discuss the DNP spectrum, the active DNP mechanisms and what we can learn about the diamond powder from DNP.

Zoom Link: https://weizmann.zoom.us/j/92088510918?pwd=bW11Rk1TKzEzeFdES3NJS1VCaTE4Zz09

Zoom Link: https://weizmann.zoom.us/j/94661424796?pwd=U0Z1YjdsbGUrV29STEZlMVhweUtXUT09 All our cells contain the same genetic information, encoded in the sequence of nucleotides that compose our DNA. The identity of different cells, and their response to different stimuli, is therefore controlled by processes regulating which subset of genes is “expressed” at a specific cell and a specific time. The first step in gene expression regulation is the binding of a special family of proteins, called transcription factors, to specific sequences in regulatory regions in the DNA. Packaging of the DNA into the dense structure of chromatin, and chemical modifications of the DNA, provide the cell with the possibility of dynamically modulating expression but add additional layers of complexity to the process in ways that are not fully understood. In my talk, I will report on our work using single-molecule optical tweezers assays to study how the thermodynamics and kinetics of transcription factor binding are modulated by these different layers of information. .

Zoom Link: https://weizmann.zoom.us/j/97142508810?pwd=S2Voc3BMYnh6RmFTYUxLbUFjQXRGZz09 Until recently, computational studies of chemical reactivity were exclusively dealt with using quantum mechanical approaches, which severely limited the system's size and accessible time scales for simulation. To bypass the need to solve Schrodinger's equation, and facilitate large-scale simulations for up to millions of atoms, both accurate and efficient models of the chemical bond have to be constructed. I will present recent advances in the field of modeling chemical reactions in large-scale, complex systems (i.e. "dirty chemistry"), with a particular focus on ReaxFF reactive molecular dynamics. Prominent applications from recent years will be highlighted, including: (a) discovery of the underlying operation principles of a novel laser-based mass-spectrometry technique, and (b) prediction of the surprising chemistry that leads to the formation of several key precursors to biomolecules of life upon the collapse of a "primordial bubble". Finally, I will present a new ReaxFF formulation that opens exciting new avenues for orders of magnitude more accurate simulations for long time scales.

Zoom Link: https://weizmann.zoom.us/j/91657907719?pwd=M2F2WlRKWGRuUHlxN0tNWFhZVUVzZz09 The genetic material of live organisms is packed and stored within the nucleus. It contains DNA wrapped around the nucleosomes, which then organized into chromatin fibers that partition into distinct compartments, which eventually fill the entire nucleus. Chromatin three dimensional topology is essential for proper accessibility of transcription factors, which control tissue-specific gene expression programs. Whereas chromatin partition into specific domains has been described in cells in culture conditions, information regarding chromatin 3 dimensional distribution in tissues within live organisms is still missing. We have imaged the chromatin in muscle fibers of live, intact Drosophila larvae, and revealed its 3 dimensional structure. Our results demonstrate novel 3 dimensional architecture of the chromatin which is evolutionary conserved, and has important implications on the regulation of gene expression.

Zoom: Link: https://weizmann.zoom.us/j/98957854014?pwd=ZTEyazd6cThxUE90L3ZJbkdkbkFWQT09 passcode: 159170 Magnetic Resonance Imaging (MRI) is a non-ionizing, non-invasive imaging modality that has become key in modern medicine. Its high value resides in a broad range of soft tissue contrasts or biomarkers that can be tuned to enable the identification and follow-up of many pathophysiological or metabolic processes. Such developments were made possible thanks to almost forty years of hardware and software development, yet access to MRI nowadays remains exclusive, bound to radiology suites in hospitals, and restricted to less than half of the world population. This limited accessibility is mostly due to its one-fits-all design and its prerequisites for intense magnetic field strength that impact cost, siting infrastructure, and clinical compatibility. One way to improve accessibility in MRI is to lower the magnetic field strength that will naturally influence cost, siting, and compatibility. Further, lowering the field strength can translate in smaller footprint designs which geometry and contrast could purposely be tuned to certain targeted applications. Indeed, relaxation mechanisms are known to change with the surrounding magnetic field, with larger T1 dispersion at low field that have for the most part been unexplored. Although very promising, many challenges arise linked to the lower intrinsic nuclear spin polarization inherent to low field technologies, calling for original and innovative approaches to reach clinical relevance. During this seminar, Prof. Najat Salameh will describe those challenges and possible solutions by presenting the current landscape of low field imaging and recent progress made at the Center for Adaptable MRI Technology, Basel University.

Zoom: https://weizmann.zoom.us/j/96278790117?pwd=T1ZjaHlxQjlEQkFIbE12UDJCazNwZz09 Two-dimensional layered (van-der-Waals) heterostructures, made by stacking different monolayers of semiconducting transition-metal dichalcogenides, have been drawing much attention as versatile platforms for studying fundamental solid-state phenomena and for designing opto-electronic devices. Interlayer excitons, electron-hole pairs that bind to each other across the interlayer spacing in these heterostructures, hold promise as key tools for probing the interlayer interface structure, and for exploring many-body interactions(1). With long lifetimes, spin polarization, and electric tunability, interlayer excitons are also promising as flexible information carriers(2, 3). However, they were mostly studied through the scope of their visible light emission, missing essential properties such as their momentum-space image or their absorption strength, necessary for rigorous study of their many-body interactions and potential applications. In this talk I will present our recent studies aimed at measuring such unknown interlayer exciton properties and their dependence on the heterostructure. I will show a new interlayer exciton in WSe2/MoS2 heterostructures which we discovered based on its light emission in infra-red wavelengths, rather than in the visible range(4). I will demonstrate its properties as inferred from its optical interrogation. Then, I will present the quantitative measurement of the elusive optical absorption spectrum of interlayer excitons using electric-field modulation spectroscopy, essential for coherent coupling of light to those excitons(5). Finally, I will reveal how time- and angle-resolved photoemission spectroscopy is used to image the interlayer exciton in momentum-space, yielding its size and binding energy, so far inaccessible through optics(5).

Zoom Link: https://weizmann.zoom.us/j/92447973616?pwd=UWJkRWdraGFVQjdPb3ByWis1bDk2Zz09 Development of targeted nanoparticle for personalized cancer therapeutics often requires complex synthetic schemes involving both supramolecular self-assembly and multiple chemical modifications. These processes are generally difficult to predict, execute, and control. I will describe a new method to accurately and quantitatively predict self-assembly of kinase inhibitors drug molecules into nanoparticles based on their molecular structures. The drugs assemble with the aid of new kind of excipient comprised of highly conjugated sulfated molecule into particles with ultra-high drug loadings of up to 90%. Using quantitative structure-nanoparticle assembly prediction (QSNAP) calculations and machine learning, a new algorithm was developed as highly predictive indicators of both nano-self assembly and nanoparticle size with unprecedented accuracy.

Link: https://weizmann.zoom.us/j/96046369379?pwd=emp0U0wwcmpNQlhsMisrNmp0bjRDdz09 Passcode: 693143 The molecular mechanisms and associated structures and dynamics of liquid-liquid phase separation (LLPS) proteins that form membrane-less organelles in cells have attracted considerable interest in recent years. EPR spectroscopy along with site directed spin labelling (SDSL) using nitroxide spin labels is a well-established technique to study dynamics of proteins. In this seminar I will discuss the dynamic properties of the spin labelled low complexity N-terminal domain of cytoplasmic polyadenylation element binding-4 protein (CPEB4NTD) in its LLPS and non-LLPS states. We found the coexistence of three CPEB4NTD populations with distinct spin label rotational correlation times before and after LLPS. We identified population I as the predominant protein species in the dilute phase, with fast motions that agree with expected dynamic properties of monomeric CPEB4NTD. We assigned population III to a compact ensemble that undergo slow motions, and population II to a looser ensemble experiencing intermediate motions. LLPS, which took place with increasing temperature is associated with increased population of II at the expense of III, while population I remains constant. At the end based on these findings, I will present a three-component equilibrium model that postulates the existence of LLPS-competent CPEB4NTD species (II and III) prior to macroscopic phase separation.

https://weizmann.zoom.us/j/93597285944?pwd=S0FJdHJ6eVpFTGJ3dHJHa3c1amJyUT09 Abstract: A long-standing challenge within density functional theory (DFT) is the development of functionals that accurately predict the band gap and electronic structure of crystalline solids. A promising candidate for this task is the screened range-separated hybrid (SRSH) functional, which has been shown to yield accurate results for finite systems when one of the parameters in the functional, the range-separation parameter, is selected a priori. In the bulk limit, however, this parameter cannot be selected non-empirically based on the ionization potential theorem, owing to the delocalized electronic orbitals. Recently, we have developed a new method for the non-empirical tuning of the range-separation parameter, that is based on the removal of an electron in a state that corresponds to a Wannier function. We have applied the method to a set of systems ranging from narrow band gap semiconductors to large band gap insulators, obtaining fundamental band gaps in excellent agreement with experiment.

Zoom Link: https://weizmann.zoom.us/j/98521602060?pwd=T1B1TEJqcXEwUW50QzBEaXd3RS9XZz09 SARS-CoV-2 outbreak of the coronavirus disease (COVID-19) has underlined the acute need for extremely sensitive, accurate, fast, point-of-care mRNA quantification sensors. Here I will show how solid-state nanopores can be used to digitally count target mRNA molecules from both biological and clinical Covid-19 samples surpassing the accuracy and gold-standard” RT-qPCR. Additionally, we applied our method for the sensing of cancer metastatic mRNA biomarkers MACC1 and S100A4 at early stage of the diseases, suggesting a potential use of the method in early precision medicine diagnostics. Moving beyond nucleic acids, I will discuss our on-going efforts towards the use of plasmonic nanopore devices for the single protein molecules identification based on partial labelling of only two or three amino acids. This research opens up vast directions for single-cell proteomics of even rarely expressed proteins.

Abstract: The present seminar will review our work in 1H LF NMR energy relaxation time technology and its application in chemical and morphological characterization and monitoring of oxidation of polyunsaturated fatty acids (PUFA) found in many important commercial products such as edible oils, foods, and biological systems. PUFA’s aggregates are related simultaneously with material’s functionality and degradation. The multiple double bonds and allylic carbons characteristics of the PUFA’s molecular structure are responsible for its oxidation susceptibility and can result in the degrade of the product’s functionality and formation of toxic substances. Wherein individual PUFA molecules have specific structures their material functionality and stability against oxidation are strongly depended on their aggregate structures such as in oils or within aqueous emulsions and specific arrangements within these structures with other components such as antioxidants is an important material parameter. The oxidation degree of PUFA’s rich materials can be measured via different methods such as volumetric, spectroscopic and chromatographic technologies. The traditional technologies based on titrimetric techniques have many drawbacks. These methods need strict time regimes during individual stages of analyzes, control of the intensity of the agitation and control of reaction components including light and atmospheric oxygen exposure. Other disadvantage of these traditional methodologies is the requirement of a large amount of solvents, being environmental unfriendly. In order to overcome the disadvantages of the traditional technologies used to monitor oxidation we are suggesting the use 1H LF NMR relaxation. This technology does not require organic solvents, complex samples preparation and the sample is preserved after analysis. The 1H LF NMR generates 2D T1 (spin-lattice) vs. T2 (spin-spin) energy relaxation time domain that is able together with self-diffusion test to characterize chemical and morphologically complex aggregate materials such as PUFA in liquid or solid assembly or in presence of interfacial forces of water. In addition, these spectra can efficiently monitor oxidation and assess antioxidants efficacy. We demonstrate the work we have done to date on the 1H LF NMR data processing optimization and the application of this technology in the characterization and monitoring of oxidation on oils on fatty acids saturated, monounsaturated and polyunsaturated. This sensor application is of relevant contributions for diverse fields such as food industries, pharmaceuticals, cosmetics and biofuels. The seminar is divided into three parts: a) Optimization of the ILT data processing technology of 1H LF NMR energy relaxation time. This study showed the efficiency of the regularization parameters for data reconstruction, and a relative high accuracy of the primal dual convex objectives (PDCO) solutions in comparison to the graphic results of real data. b) Developing of intelligent NMR relaxation sensor applications of fatty acids (FA) with saturated chains, MUFA and PUFA-rich oils for their chemical and physical/morphological characterization and monitoring of their autoxidation. Detailed fingerprinting chemical and morphological maps were generated for saturated FAs, MUFAs, PUFAs and their oxidation polymerized final products. It was possible to propose peak assignments to the various spin-lattice (T1) and spin –spin (T2) energy relaxation time proton populations (TD) based on the molecular segmental motions of the different fatty acids chemical and structural segments (e.g., glycerol; double bonds; aliphatic chains; and tails) to generate an explicatory dictionary of T1 and T2 values with chemical and physical/morphological structures and their changes due to oxidation. c) Developing of intelligent 1H LF NMR energy relaxation time domain sensor application for PUFA-rich oil-in-water emulsions characterization and monitoring autoxidation. Emulsions based on linseeds, very rich in α-linolenic acid PUFA (18:3) and structural oleosin protein and other emulsification agents naturally producing nano-scale oxidation stable oil bodies, were formed from linseed in water. The linseed emulsions enriched with PUFA-rich fish oil were analyzed under thermal oxidation conditions, using 1H LF NMR T1-T2 energy relaxation time reconstruction for determining the oil bodies composition and structure and oxidative stability.

Zoom Link: https://weizmann.zoom.us/j/98510631069?pwd=QzVFbzNxMHZETWwrM0xjbVBmV3FDdz09 Biofilms are aggregates of cells that form on surfaces and interfaces. A major characteristic of biofilms is the self-secretion of an extracellular matrix, that is composed of biopolymers, mainly proteins, polysaccharides, and nucleic acids. Using a variety of biophysical methods, we study the basic interactions between matrix components that lead to the formation of a 3D network. In this talk I will describe our recent findings, going all the way from peptides through full-length proteins to whole biofilms.

Zoom Link: https://weizmann.zoom.us/j/95267372668?pwd=dEhvRlA3SGtvVTQ1QnVmZ3JJdTZEQT09 Thermosensitive microgels are widely studied hybrid systems combining properties of polymers and colloidal particles uniquely. This study explores the frequency-dependent linear viscoelastic properties of dense suspensions of micron-sized microgels in conjunction with an analysis of the local particle structure and morphology-based on superresolution microscopy. By identifying the dominating mechanisms that control the elastic and dissipative response, we can explain these widely studied soft particle assemblies' rheology. Interestingly, our results suggest that the polymer brush-like corona's lubrification reduces friction between the microgel contacts.

https://weizmann.zoom.us/j/99592122461?pwd=MjM4ZDN0ZDFVeGZOYkdqQi9CUy9uUT09 Semiconductor nanowires (NWs) are quasi 1D nanostructures, exhibiting distinctive physical properties suitable for efficient bottom-up design of nanodevices. A challenging limiting step of their integration into planar functional systems is the difficulty to align them on horizontal surfaces. One simple and elegant way to avoid post growth assembly of NWs is to grow them horizontally in the first place. Over the past decade, our group has established the surface guided growth of horizontal semiconductor NWs aligned by crystalline substrates with controlled crystallographic orientations, directions and position. As the NWs are comprised of different semiconductors, they are optically active is different spectral regimes including the UV and visible range. However, optical activity in the pivotal infrared (IR) regime is not yet exhibited for guided NWs and a systematic exploration of it can pave the way for effective devices for telecommunication and night vision technologies. CdTe, a narrow band-gap II-VI semiconductor (~1.5 eV), is an attractive candidate owing to its promising optical and electrical properties, making it an attractive material for solar cells and near IR (NIR) photodetectors. Its alloys with mercury, known as MCT (HgxCd1-xTe) are already central components of efficient IR photodetectors due to continuous bandgap narrowing with growing percentage of mercury. In this work, we present the vapor-liquid-solid (VLS) growth and self-alignment of surface guided CdTe NWs with a wurtzite crystal structure on flat and faceted sapphire substrate (α-Al2O3). The NWs were integrated into fast IR photodetectors showing high on/off ratio of up to ~104 and, to the best of our knowledge, the shortest response times (~100 ms) to IR irradiation with respect to other CdTe based photodetectors. Attempts to create HgxCd1-xTe through cation exchange show initial conversion (~2%) of the crystal, though with significant bandgap narrowing of ~ 55 meV. These findings pave the way for simple and elegant fabrication of CdTe NWs’ based NIR nano-photodetectors, which can be expended to a wide range of Mid-IR and Far-IR photodetectors with small size through bandgap engineering.

We model intrinsically disordered proteins (IDPs) as associative polymers (APs). We study the kinetics of gelation in solutions of amphiphilic polymers that contain strongly associating stickers connected by long soluble chain segments. We explore the relation between primary sequence and droplet morphology in APs in poor solvent. We find that gelation of APs can be suppressed by grafting them to surfaces, a possible way to control aggregation of IDPs. Zoom Link: https://weizmann.zoom.us/j/99868477151?pwd=U3hFTWhjZ05nT3Ryd1ZHOXJ6Z3Y1Zz09

Zoom Link: https://weizmann.zoom.us/j/93181739182?pwd=YTd0K1drTmZSdnB0bElFZVI4K0NXdz09

Some fundamental concepts of catalysis are as of yet not fully explained but are of paramount importance for the development of improved supported metal catalysts for chemical industries and environmental remediation. Structure (in)sensitivity is such a fundamental physical concept in catalysis, which relates the rate of a catalytic reaction per unit surface area to the size of a nanoparticle. If this rate per unit surface area changes with catalyst particle size, a reaction is termed structure sensitive. Conversely if it does not - a reaction is termed structure insensitive. Historically, many fundamental physical concepts explaining the behavior of metal nanoparticular catalysts have been formulated by studying single crystal facets with surface science techniques which has left a considerable gap in our basic knowledge of catalysts at work. By using and developing state-of-the-art operando (micro)spectroscopic techniques, inter alia operando high-temperature high-pressure FT-IR, in-situ high-resolution STEM, and quick-X-ray absorption spectroscopy (quick-XAS) with millisecond time resolution, over the last few years I have been exploring the fundamental physical concepts behind fundamental structure-activity relationships of catalytic reactions by studying non-model catalysts at work. For example, by applying these methods to study a structure sensitive reaction (carbon dioxide hydrogenation) to a structure insensitive one (ethene hydrogenation) we show that the same geometric and electronic effects that we find to explain structure sensitivity make it unlikely for structure insensitivity to exist (while we do observe it empirically). However, interestingly, in the case of the structure insensitive ethene hydrogenation reaction, such size-dependent nanoparticle restructuring effects as the decrease of the reversibility of adsorbate-induced restructuring and the increase of carbon diffusion with increasing particle size are observed by quick-XAS (see Figure 1). While for the structure sensitive CO2 hydrogenation no such perturbation was observed. We further show that this particle size dependent restructuring induced by ethene hydrogenation can make a structure sensitive reaction structure insensitive. Hence, we may postulate that structure insensitive reactions should rather be termed apparently structure insensitive, which changes our fundamental understanding of the age-old empirical observation of structure insensitivity.

One of the key advantages in using light-sensitive hydrogel biomaterials is the ability to spatially structure cell scaffolds with three-dimensional mechanical cues that guide cellular morphogenesis. However, this has proven difficult because of the high toxicity associated with the cross-linking interactions. To overcome this challenge, we developed a new paradigm in micro-patterning using a reversible temperature-induced phase transition from liquid to solid vis-à-vis lower critical solubility temperature (LCST). This facilitates reduced transport kinetics of the polymer chains in solution, thus enabling crosslinking that is truly compatible with cell-laden 3D culture. Cellularized constructs were patterned to reveal a difference in morphogenesis between chemically crosslinked “stiffer” and physically crosslinked “softer” regions. Emphasizing the importance of mechanical heterogeneity in cellular morphogenesis, the results validate cutting-edge technology that can provide scientists with a robust set of tools for engineering cell and tissue growth in three dimensions.

Zoom Lecture: https://weizmann.zoom.us/j/95418425823 Deposition and attachment are key steps in colonization and fouling of surfaces by bacteria and other microorganisms, undesired in most applications. Soft hydrophilic surfaces are attractive as potential low-fouling coatings, however, deposition on such surfaces open questions regarding microscopic mechanism of attachment and its relation to deposition kinetics, not addressed in the current picture. In the talk, I will highlight our effort to understand deposition and attachment of bacteria and microparticles on low-fouling surfaces and develop appropriate characterization techniques and models.

Zoom Lecture: : https://weizmann.zoom.us/j/91487772614 Structural superlubricity may provide a viable route to the reduction of friction and wear. In this talk I will present results of fully atomistic numerical simulations of static and dynamical properties of graphite/hexagonal boron nitride (h-BN) heterojunctions, performed adopting a recently developed inter-layer potential. We found that structural superlubricity at interfaces between graphite and h-BN persists even for the aligned contacts sustaining external loads. A negative friction coefficient, where friction is reduced upon increasing normal load, is predicted. It is demonstrated that further control over the physical properties of 2D layered materials can be gained via tuning the aspect-ratio of nanoribbons. The sliding dynamics of the edge-pulled nanoribbons is found to be determined by the interplay between in-plane ribbon elasticity and interfacial lattice mismatch. Our results are expected to be of general nature and should be applicable to other van der Waals heterostructures.

Zoom lecture https://weizmann.zoom.us/j/96236417861 Mechanical sensing in cell fate decision making: from nuclei to embryos. Cells constantly probe extracellular mechanics by assessing the resistance to applied forces via adhesion, cytoskeletal, and nuclear mechanotransducers and the emerging signals direct cell-fate decisions during development and regenerative processes. The conversion of forces into biochemical cues depends on the rheological properties of subcellular elements and multicellular systems, which have been optimized during metazoan evolution. In my talk, I will present micropipette nuclear aspiration measurements of cells that express or lack the expression of different combinations of A- and B-type lamin proteins. By evaluating the mechanical contributions of assembled and disassembled lamin filamentous, and the interactions with stabilized condensed chromatin, we propose a nuclear viscoelastic model that supports a shockabsorbing response for protecting the genetic material from instantaneousimpact and a viscoelastic regime that permits slow dissipation under constant load. In a living organism, the genetic material is also protected by a physical decoupling mechanisms of the cell nucleus, which is affected by nuclear stiffening during ageing. If time permits, I will also discuss the development in situ rheological systems for performing non-invasive measurements of oocytes and embryos during preimplantation development. We combine rheology of the whole oocyte and the internal cytoplasmic mass. These stress-strain relationships are correlated with oocyte fertilization capacity, where negative outcome is underlined by impaired cytoskeletal organization.

This seminar consists of two parts. The first part is related to the investigation of mechanism of tunable domain wall (DW) conductivity in the ferroelectric LiNbO3 thin films with sub-µm thickness, Using a combination of scanning transmission electron microscopy (STEM) and local probe techniques we generate and delineate the electrically-charged 180º DWs and test their conducting behavior using local probe spectroscopy and imaging under electrical bias. More importantly, electrical tunability of DW conductivity by sub-coercive voltage is realized through the changes in DW conformity. The obtained results provide tangible evidence that the charged DWs can be used as multilevel logic elements in analog computing devices. The second part discusses the dynamic switching behavior in the HfO2-based films investigated by a combination of local probe microscopy and pulse switching techniques. Application of HfO2-based materials to ferroelectric memory and logic devices has generated considerable interest as they allow overcoming significant problems associated with poor compatibility of perovskite ferroelectrics with CMOS processing. High-resolution studies of the time- and field-dependent evolution of the domain structure in La:HfO2 thin film capacitors provides an insight into the mechanism of imprint - one of the main degradation effects hindering integration of ferroelectric HfO2 into CMOS-compatible memory technology.

Engineering vascularized constructs represents a key challenge in tissue engineering. Sufficient vascularization in engineered tissues can be achieved through coordinated application of improved biomaterial systems with proper cell types. We have shown that vessel network maturity levels and morphology are highly regulated by matrix composition and analyzed the vasculogenic dynamics within the constructs. We also explored the effect of mechanical forces on vessels organization and demonstrated that morphogenesis of 3D vascular networks is regulated by tensile forces. Revealing the cues controlling vascular network properties and morphology can enhance tissue vascularization and improve graft integration prospects.

Much has been written of the potential of ultra-high field MR scanners, such as 7 tesla, due to their inherently higher signal-to-noise ratio (SNR). This native boost is of great use in making techniques that operate in a low SNR regime, such as spectroscopy, more viable. Application of spectroscopic techniques at 7 tesla also come with a secondary, yet perhaps more important benefit in increased spectral resolution. This can allow for the quantitative investigation of metabolites that are difficult to resolve and measure reliably at lower field strengths. This seminar will relate early experiences in spectroscopy from the Siemens Terra 7T system at the University of Glasgow. This will include the optimisation of single voxel techniques for clinical studies, such as the measurement of glutamate in neuroinflammatory conditions, as well as an update on development work, such as a spectral 2D correlated spectroscopy (COSY) acquisition for investigation of glioma tumours, including a focus on 2-hydorxyglutarate. It will also cover the development of a novel MR spectroscopic imaging (MRSI) technique based on the EPSI sequence, which will allow for high resolution, full spectral bandwidth 7T acquisitions in a clinically viable time, by application of compressed sensing methods

Spatial and temporal control are critical properties to advance functional macromolecular materials in order to mimic key features of living systems. In my lecture, I will discuss our methodology in developing multicomponent supramolecular polymerization strategies in water. Using peptide-polymer conjugates we are able to address non-equilibrium states in the preparation of thermoresponsive hydrogel materials. Here, we make use of charge regulated ß–sheet selfassembly of oligopeptides and introduce reactive oxygen species (ROS) responsive subdomains to tune the time-domain of supramolecular polymerization. Using multicomponent assembly protocols, we currently explore the co-presentation of different epitopes and immunostimulating agents at the surface of supramolecular polymers. I will briefly discuss this modular supramolecular platform for immunotherapy applications and the development of multifunctional antitumor vaccines.

For the past two years we have been involved in the synthesis and characterization of new Uranium-based endohedral fullerenes and have obtained X-Ray crystal structures for several of these compounds. Some are mono-uranium species, U@C2n, while some are di-uranium compounds (see structure at the left), U2@C2n.1 Very recently we isolated two new mono-uranium compounds that violate the Isolated Pentagon Rule (IPR) with a C76 and a C80 cage possessing fused five-membered rings (pentalenes) on their surfaces.2 Still other endohedral structures are much more interesting and totally unanticipated, with formula U2X@C2n, where X= C, O, S or N and 2n= 72, 78 or 80, which reveal interesting metal-cage interactions and totally unprecedented clusters trapped inside. Some of the carbide compounds have been crystallized and the encapsulated U2C cluster (in U=C=U@C80) exhibits unprecedented bonding with totally unanticipated properties (see structure to the right).3 Finally, we have found that bis-porphyrin capsules exhibit exquisitely selective supramolecular binding for several of these uranium-based endohedral fullerene compounds.4 The synthesis, purification and characterization of these interesting endohedral fullerenes will be presented and discussed, along with very recent results about uranium-based endohedrals. References 1. Zhang, X.; Wang, Y.; Morales-Martínez, R.; Zhong, J.; de Graaf, C.; Rodríguez-Fortea, A.; Poblet, J. M.; Echegoyen, L.; Feng, L.; Chen, N., J. Am. Chem. Soc. 2018, 140 (11), 3907-3915. 2. Cai, W.; Abella, L.; Zhuang, J.; Zhang, X.; Feng, L.; Wang, Y.; Morales-Martínez, R.; Esper, R.; Boero, M.; Metta-Magaña, A.; Rodríguez-Fortea, A.; Poblet, J. M.; Echegoyen, L.; Chen, N., J. Am. Chem. Soc. 2018, 140 (51), 18039-18050. 3. Zhang, X.; Li, W.; Feng, L.; Chen, X.; Hansen, A.; Grimme, S.; Fortier, S.; Sergentu, D.-C.; Duignan, T. J.; Autschbach, J.; Wang, S.; Wang, Y.; Velkos, G.; Popov, A. A.; Aghdassi, N.; Duhm, S.; Li, X.; Li, J.; Echegoyen, L.; Schwarz, W. H. E.; Chen, N., Nature Comm. 2018, 9 (1), 2753. 4. Fuertes-Espinosa, C.; Gómez-Torres, A.; Morales-Martínez, R.; Rodríguez-Fortea, A.; García-Simón, C.; Gándara, F.; Imaz, I.; Juanhuix, J.; Maspoch, D.; Poblet, J. M.; Echegoyen, L.; Ribas, X., Angew. Chem. Int. Ed. 2018, 57 (35), 11294-11299.

The control/elimination of microorganisms, viruses and micropollutants is relevant in many water treatment systems. We developed Laser-induced graphene (LIG), a three-dimensional, porous, electrically conductive graphene material generated by irradiation of polymer substrates composites, which have strong antifouling and antimicrobial properties. This method to “laser-print” electrically conductive antifouling graphene coatings on membranes holds promise for advanced water treatment and purification

Halide perovskites (ABX3) attracted much of attention in the last years due to their excellent photovoltaic activity. They are unique in the sense that they exhibit long carrier lifetime despite having many apparent structural defects. Recent studies in our group concluded that this unique behavior is due to strong coupling between the electronic band structure and the strongly anharmonic motion of the atoms within the crystal. Therefore, it is imperative to understand the source of anharmonic atomic motion in this class of materials. Studies have indicated the B-cation lone pair to be a possible source for strong anharmonic behavior in the perovskite crystals. In order to understand the anharmonic behavior and its origin, I investigated a series of perovskites with different lone pair stereoactivity. Using low frequency Raman spectroscopy, I quantified the level of anharmonicity and determined the influence of the B-cation lone pair on the structural dynamics.

Abstract: In recent years, Van der Waals (2D) materials, have attracted increasing attention due to their distinctive physical properties. As layered materials, they have been considered for flexible electronics as they can sustain strain higher than 10% without breaking down, although they are only 1-3 atom thick. Their superior mechanical properties led to a renewed interest in the mechanics of thin membranes linked to condensed matter physics. In this talk we will show how we can apply non-uniform strain to a suspended Van der Waals material (WS2) and alter the dynamics of excitons and trions. Surprisingly, we find that as we increase the non-uniformity of the strain, we are able to convert the excitons into trions with almost 100% efficiency without any electrostatic gating. Our results explain inconsistencies in previous experiments and pave the way towards new types of optoelectronic devices.

Planarity plays a crucial role in determining the electronic and optical properties of π-conjugated backbones. Here I will discuss two examples of non-planar and planar systems: twisted acenes and planar furan-based macrocycles. In the first part, I will demonstrate how twisting affects the electronic, optical and chiroptical properties of acenes. We have introduced a series of twisted acenes, having an anthracene backbone diagonally tethered by an n-alkyl bridge, which induces different degrees of twisting. This helically-locked system allows us to systematically monitor the effect of twisting on electronic and optical properties of anthracene. The effect of twisting on chiroptical properties, charge delocalization and π-conjugation will also be demonstrated. In the second part, I will present bifuranimide as a stable furan containing analog, which resulted in the introduction of the first macrocyclic furans. These π-conjugated macrocycles were found to be completely planar, in contrast with thiophene macrocycles which are highly-twisted. The prospects of macrocyclic furans as π-conjugated analogs of crown-ethers and synthons for cycloarenes by multiple Diels–Alder cycloadditions will be discussed.

Following our recent observations of contraction waves in the primitive epithelium of Placozoa, we develop a model of tissues as sheets of contractile cells. The simple model assumes only a strain-threshold for contraction, and explains/predicts a variety of unique and surprising phenomena, e.g.: contraction waves in response to external stress, spontaneously-compressed steady-state, emerged limit-cycles, mechanical frustration and active resistance to rupture. In the talk I will present both the experimental observations and the model results. This model of “active cohesion” may be relevant to any epithelial tissue, to manufacturing of synthetic active materials, and to models of evolution of multicellularity.

Catalysts play a pivotal role in modern society since they enable the production of chemicals and fuels that we rely on every day. The search for new and improved solid catalysts to speed up and access novel chemical reactions is a never-ending challenge, but has become increasingly important due to the environmental challenges that we are currently facing. For this purpose, constant improvements in synthesis methods are required in general, but more specifically, improvements in characterization methods in terms of spatiotemporal resolution is the key toward tailored catalytic reactions. In an ideal case, a real time visualization of the reactants, intermediates and reaction products on the surface of the catalyst is possible, allowing for a molecular movie of the catalytic reaction in space and time. Certain characterization techniques exist that are sensitive enough to measure the reactants at the reaction surface of the catalyst (e.g. vibrational spectroscopy). However, in order to really understand the catalytic behaviour, we need to move toward single molecules and atoms at the (sub-) nanometer scale. Improvements in this direction have already led to an increased understanding of the catalytic processes, but the combination of nanometer resolution in space and pico- to nanosecond resolution in time has remained largely elusive in the world of heterogeneous catalysis.  In this lecture, I will discuss the state-of-the-art of time- and space-resolved spectroscopy and microscopy methods for catalysis research, and discuss the movement in the field toward the visualization of individual molecules at catalyst surfaces to construct the ultimate “molecular movie of sustainability” (Figure 1). Special emphasis will be on the compatibility of operando characterization techniques with the desired reaction environment (e.g. liquid or gas phase) and what we can do to ensure the spatiotemporal resolution is not hampered by the reaction requirements of the catalytic reactions. I will touch upon a variety of techniques, ranging from (time-resolved and surface-enhanced) vibrational spectroscopy, single molecule fluorescence, scanning probe techniques combined with optical and vibrational spectroscopy, as well as X-ray spectroscopy and microscopy.

Tissues are made up of cells and an extracellular matrix (ECM), a cross-linked network of fibers that exhibits complex mechanics. Cells actively alter the ECM structure and mechanics by applying contractile forces. These forces can propagate far into the matrix and allow for remote cellular sensing. We study experimentally and computationally how cell-generated forces are transmitted in fibrous environments, the associated physical mechanisms, and the ability of the propagated forces to support mechanical interaction between distant cells. Also, we demonstrate how the dynamic changes in the ECM structure can lead to improve transport of molecules traveling between the cells, facilitating mechano-biochemical interactions. Such long-range force interactions through the ECM can drive large-scale cooperative biological processes, such that occur during wound healing and morphogenesis. Our work can also provide design parameters for biomaterials used in tissue engineering applications.

High-performance materials with elevated operating temperatures and robust mechanical properties, are essential for a wide variety of emerging applications, such as in functional adhesives, automobiles, aerospace, and coatings. Polyhexahydrotriazines (PHT) are new promising high-performance thermosets exhibiting enhanced thermal and mechanical properties.1 The performance and utility of PHT-based materials is further enhanced by the ability to design new material properties based on changes in the molecular structure.2 We demonstrated a new solvent-free approach for the fabrication of PHT based on low-melting-point diamines enabling the production of adhesives with comparable properties to well-established epoxy adhesives. Furthermore, these versatile materials could be degraded at different rates in acidic conditions based on the nature of the starting diamine molecular structure. Controlling the degradation is extremely valuable in composites and adhesives in order to be able to recycle and rework the materials. In the second part of my talk I will show how the ability to control and adapt peptide conformation is crucial for the rational design and control of their function.3,4 We demonstrated by end-to-end distance measurements using Double Electron-Electron Resonance (DEER) EPR method that we can tune the conformations of the backbone while maintaining the sequence of the side-chains. Interestingly, tuning of the backbone has an effect on peptide propensity to aggregate or stabilize nanoparticles. Such knowledge is critical for designing new materials for various biotechnological applications. 1. J. M. García, G. O. Jones, K. Virwani, B. D. McCloskey, D. J. Boday, G. M. ter Huurne, H. W. Horn, D. J. Coady, A. M. Bintaleb, A. M. S. Alabdulrahman, F. Alsewailem, H. A. A. Almegren, J. L. Hedrick. Science 2014, 344, 732–735. 2. R. Kaminker, E. B. Callaway, N. D. Dolinski, S. M. Barbon, M. Shibata, H. Wang, J. Hu, C. J. Hawker. Solvent-Free Synthesis of High-Performance Polyhexahydrotriazine (PHT) Thermosets. Chem. Mater. 2018, 30, 8352–8358. 3. R. Kaminker, I. Kaminker, W. R. Gutekunst, Y. Luo, S.-H. Lee, J. Niu, C. J. Hawker, S. Han. Tuning Conformation and Properties of Peptidomimetic Backbones through Dual N/Cα-Substitution. Chem. Commun. 2018, 54, 5237–5240. 4. R. Kaminker, A. Anastasaki, W. R. Gutekunst, Y. Luo, S.-H. Lee, C. J. Hawker. Tuning of Protease Resistance in Oligopeptides through N-alkylation. Chem. Commun. 2018, 54, 9631–9634.

Less is more! By using extremely low power refocusing π pulses in echo train sequences the coherence lifetime, T2, of the central transition of half-integer quadrupolar nuclei can be largely extended. This effect is particularly impactful in systems dilute in NMR active nuclei, where sources of decoherence are scarce. Crucial to this lifetime extension is the avoidance of coherence transfer to short-lived non-symmetric “killing” transitions. For 17O in polycrystalline α-quartz we were able to retain coherent magnetization for over four minutes on the transverse plane. This translates into enormous sensitivity gains for echo train acquisition after addition of the long living echoes. By combining satellite population transfer schemes with a low power CPMG on 17O in quartz, we obtain over a 1000-fold sensitivity enhancement compared to a spectrum from a free induction decay acquired at a more typical rf field strength. This enhancement allows the acquisition of a highly resolved 17O spectrum within less than one hour, despite its low natural abundance and a spin-lattice relaxation time of approximately 900 s. In this talk I will present a thorough analysis of the effects of pulse power on the echo intensity, coherence lifetime and line shape integrity. Finally, we apply this approach on various crystalline and glassy inorganic solids, including other low sensitivity nuclei, such as 33S and 45Ca, showing that it can be beneficial for a large number of systems.

Atomic/Molecular layer deposition (ALD/MLD) are based on the use of hetero- and homo-bifunctional organic or metal-organic compounds that vaporize, chemisorb onto and react with an appropriately functionalized surface. Both ALD and MLD allow temporal separation of any number of precursors, each of which produces self-limiting adsorption/reaction on the surface so that typical uptake is limited to ~one monolayer of any given precursor. This leads to growth controlled at the monolayer level and self-limiting reactions that have shown extreme conformality, even into ultra-high-aspect-ratio and porous substrates. In my talk I will show how utilization of carefully chosen M/ALD process enables functionalization of interfaces. I will show to sides of the coins for surface modification; namely turning “inert” interface into functional interface/interphase (e.g. inert interface into enantioselective interface) or by changing active interface into inert interface (e.g. protection layer on reactive surface in batteries). In the enantioselective example I will address a question with both fundamental and applicative significance: can we grow molecularly thin films from the vapor phase, which maintain a desirable chemical property originated from the source precursor. This question can be exemplified by a variety of chemical properties, such as MLD of enantioselective thin films from chiral building blocks (e.g. volatile amino acids), thin film deposition of molecular traps, and more.

The implementation of an organic reaction on industrial scale requires not only the adjustment of scale, but not less importantly a different way of looking at it. In addition to focusing on the reaction parameters, focusing on the process is essential. This add the process-way-of-thinking to the scope of the industrial chemist. In this talk a process-way-of-thinking will be presented via a case study containing: 1. New chemistry (to the best of our knowledge) for synthesis of organic compound containing sulfur.[1] 2. Implementation of this chemistry in a scalable manner. 3. Some industrial considerations required upon scale up. 4. Application of the above in a telescoping (domino) type process. [1] PCT/US2018/060659

Growth of biological tissues and shape changes of thin synthetic sheets are commonly induced by stimulation of isolated regions (inclusions) in the system. These inclusions apply internal forces on their surroundings that, in turn, promote 2D layers to acquire complex 3D configurations. We focus on a fundamental building block of these systems, and consider a circular plate that contains an inclusion with dilative strains. We derive an analytical model that predicts the 2D-to-3D shape transitions in the system and compare the results with numerical simulations. Then, we utilize this model to analyze the interaction between two inclusions that undergo buckling instability.

Single crystal X-ray diffraction is arguably the most definitive method for molecular structure determination, but the inability to grow suitable single crystals can frustrate conventional X-ray diffraction analysis. Building on a prolonged examination of hydrogen-bonded frameworks and inclusion compounds derived from guanidinium organosulfonates, we have devised an approach to molecular structure determination that relies on a versatile toolkit of these host frameworks, which form crystalline inclusion compounds with target guest molecules in a single-step crystallization. This approach complements the so-called crystalline sponge method that relies on diffusion of the target into the cages of a metal-organic framework, while circumventing many of its challenges. The peculiar properties of the host frameworks enable rapid stoichiometric inclusion of a wide range of target molecules with full occupancy, typically without disorder and accompanying solvent, affording well-refined structures. Moreover, anomalous scattering by the framework sulfur atoms enables reliable assignment of absolute configuration of stereogenic centers. An ever-expanding library of organosulfonates provides a toolkit of frameworks for capturing specific target molecules for their structure determination. This presentation will describe examples of this approach to structure determination, preceded by an account of the unusual properties and resilience of these hydrogen-bonded frameworks, their substantial diversity of framework architectures, and their utility in other applications.

In the history of many families, all that remains about the fate of an ancestor for whom all traces were lost are rumors, often in conflicting versions. One of the most gratifying pleasures of a genealogical quest is to unveil the true story. Selected examples taken from the lecturer’s personal history will demonstrate this.

Glycans are ubiquitous in nature and participate in a wide variety of biological processes, that span from mediating cell-cell interactions to modulating protein stability and folding. Glycan involvement in diverse biological functions can be rationalized by the equally extensive potential for structural diversity. They vary not only in monosaccharide composition and primary sequence, like proteins and nucleic acids, but also the monosaccharides can vary in ring sizes, linkage types, and functional group modifications. Therefore, their structural complexity has the potential for encoding a myriad of functions. However, it is this “structural richness” that hampers progress in stablishing structure-function relationships, simply because tools and strategies for structure determination are lacking. We are delineating three-dimensional glycan solution structure to gain insight into how they function, which should facilitate development of glycan-based vaccines, drug delivery systems, and antibiotics of the future. To this end, we use heteronuclear multidimensional NMR to determine conformations and dynamics of 15N, 13C enriched oligo- and polysaccharides. We have detected interresidue hydrogen bonds and used RDCs to delineate the relative orientations of the rigid monosaccharide building blocks. However, RDC measurements are fraught with errors from strong coupling effects. Thus, we have developed methods to accurately measure one-bond 1H-13C splittings and 13C-13C splittings as well as RDCs. I will illustrate the application of these methods for bacterial polysaccharide model systems and show how we applied them to support the two-residue per turn helical structure of 2-8 tetrasialic acid and the smaller conformationally stable dimer in solution at low temperatures.

We investigate theoretically a model system of colloids in water. The colloid size is neither very small compared to the Debye length, nor very large. We look at the orientation of the colloid near a surface, and find bistable behavior. This may have implications for flow in microfluidic channels, and for crystallization near surfaces.

Additive manufacturing, which is fabrication through printing processes, has gained a lot of interest in the academy and industry, and is considered as the next industrial revolution. The synthesis and formulations of new inks compositions will be presented, along with their applications in various fields. New materials and processes for 2, 3, and 4D printing will be introduced, for fabrication of objects composed of hybrid materials, ceramics, glass, shape memory polymers, elastomers and hydrogels. Examples of applications of these materials will be presented, such as in soft robotics, drug delivery systems, 3D electrical circuits, responsive connectors, and medical devices.

In a couple of years from now, we will finish kernel programming for Spinach – a spin dynamics simulation library that supports all types of magnetic resonance spectroscopy, from Gd3+ DEER, through DNP and NMR, and all the way to singlet state diffusion MRI, including chemical kinetics, optimal control, and advanced relaxation theories. This level of generality hinges on: 1. The ability to treat classical degrees of freedom (diffusion, hydrodynamics, radiofrequency and microwave phases, stochastic tumbling, etc.) at the same conceptual level as spin degrees of freedom – the corresponding classical equations of motion must be integrated into the density matrix formalism. 2. The ability to survive enormous Kronecker products. A well digitised medical phantom would have at least a hundred points in each of the three directions, meaning a dimension of at least 1003 = 106 for the spatial dynamics generator matrices. At the same time, a typical radical contains upwards of ten coupled spins, meaning a Liouville space dimension of at least 410. Direct products of spin and spatial dynamics generators would then have the dimension in excess of 1012 even before chemical kinetics is considered. 3. Code parallelisation over cluster architectures, including the possibility of using a GPU on each node of the cluster. The principal problem is parallelisation mode switching between powder averages, indirect dimensions of pulse sequences, frequency points of frequency domain simulations, etc. – each simulation type would in general require a different mode of parallelisation and GPU utilisation. This report is about solving all of this, and on where the dark art of simulating a time-domain magnetic resonance experiment stands at the moment. Two recent innovations are the abandonment of Liouville equation in favour of Fokker-Planck equation as the core formalism, and the use of tensor structured objects that never open Kronecker products. A separate story is recent GPUs: NVidia Tesla V100 performs ~1013 double-precision multiplications per second – an astounding amount of computing power that is surprisingly easy to use.

Several natural processes are mediated by the interactions between organic and inorganic materials. The immune response towards an implant inserted into the body is mediated by proteins. Composite materials are formed by the interactions of organic materials (usually proteins) and minerals. Biofouling, the process in which organisms attached to surfaces, is also mediated by organic molecules. Understanding the nature of interactions between organic and inorganic materials will bring to the development of improved implants, new composites and antifouling materials. This lecture will present single-molecule force spectroscopy measurements of the interactions between individual biomolecules (either amino acid residues or short peptides) and inorganic surfaces in aqueous solution. Using this method, we were able to measure low adhesion forces and could clearly determine the strength of interactions between individual amino acid residues and inorganic substrates. Our results with peptides also shed light on the factors that control the interactions at the organic-inorganic interface. Based on our knowledge from single molecule experiments, we designed a short peptide (tripeptide) that can spontaneously form a coating that resists biofilm formation. Our results clearly demonstrate the formation of a coating on various surfaces (glass, titanium, silicon oxide, metals and polymers). This coating prevents the first step of antifouling, which involves the adsorption of bioorganic molecules to the substrate. In addition, it significantly reduces the attachment of various organisms such as bacteria and fungi to surfaces. Another variation of this peptide can encourage the adhesion of mammalian cells while preventing biofilm formation.

abstract Warm dense matter (WDM) is state of matter characterized by temperatures of the order of 10,000 K and nuclear densities of magnitude significantly higher than those found in ordinary condensed matter. WDM is found in many fields of physics, chemistry, planetary sciences, and even industry: stellar and planetary science, laser-induced chemical processes in solids and on surfaces as well as plasma physics. Nowadays, using intense lasers, WDM properties can be investigated in the laboratory, thus requiring attention to theoretical research for interpretation and understanding of the results. The theoretical description of the regime is complex, being the intermediate between condensed matter physics (i.e., quantum description) and plasma physics (classical thermodynamics). WDM is often described theoretically using finite-temperature Kohn-Sham (KS) density functional theory (DFT) calculations, with reasonably good agreement to experiments. These calculations in finite (non-zero) temperatures are costly due to the large number of fractionally occupied KS orbitals that are involved. The computational cost exhibits cubic scaling with temperature. Stochastic density functional theory (sDFT), developed recently [1,2,3] appears to be a viable approach to WDM since it is “orbital-free” and yet fully KS. The sDFT approach uses the Fermi Dirac occupation operator to calculate the energy, and finds the electronic density and other expectation values by executing the trace in a stochastic way using random orbitals; in doing so, it skips over the step of calculating the KS orbitals. We further use the stochastic trace formula to calculate the conductivity based on Kubo-Greenwood formula. In the talk, convergence of the free energy will be discussed, as well as calculations of equations of states and statistical convergence of the conductivity when calculated based on stochastic thermal DFT. Transition to metallization in he-h systems was seen in temperature of ~60kK using the stochastic approach. [1] R. Baer, D. Neuhauser, E. Rabani, Phys. Rev. Lett. 111, 106402 (2013) [2] Y. Cytter, E. Rabani, D. Neuhauser, and R. Baer Phys. Rev. B 97, 115207 (2018) [3] Yael Cytter, Eran Rabani, Daniel Neuhauser, Martin Preising, Ronald Redmer, and Roi Baer Phys. Rev. B 100, 195101 (2019)

Archival documents from the Ukraine have only recently become available in Israel. These amazing documents (from the years 1880-1936) have enabled the preparation of pages of testimony for Yad Vashem – pages which serve as the sole memory for Jews who perished in the Holocaust. Rachel Karni has spent much time over the last three years researching the town that her mother came from. From the information gathered, she has been able to compile pages of testimony for people about whom almost nothing, except their names and the fact that they had been murdered, had been known previously. Rachel will speak about the results of her very interesting detective work. The methodology she employed can be replicated for other places. Originally from New Jersey, USA, Rachel lives in Merkaz Shapira and was, for many years, the head of the English Department at the Shafir Religious High School.

Morphogenesis is one of the most remarkable examples of biological self-organization. Despite substantial progress, we still do not understand the organizational principles underlying the convergence of this process, across scales, to form viable organisms. We focus on the mechanical aspects of morphogenesis using Hydra, a small multicellular fresh-water animal, as a model system. Hydra has a simple body plan and is famous for its ability to regenerate its whole body from small tissue segments. I will show that the nematic order of the supra-cellular actin fibers in regenerating Hydra defines a coarse-grained field, whose dynamics provide an effective description of the morphogenesis process, with the topological defects in the nematic order acting as effective organizing centers. I will further describe our attempts to directly probe the influence of mechanics on morphogenesis, by applying various external mechanical constraints on regenerating Hydra.

Cardiovascular disease is a result of genetic and environmental risk factors that together generate arterial and cardiac pathologies. Blood vessels connect multiple organ systems throughout the entire body allowing organs to interact via circulating messengers. Multimodality imaging achieves integration of these interfacing systems’ distinct processes, quantifying interactions that contribute to cardiovascular disease. Noninvasive multimodality imaging techniques are emerging tools that can further our understanding of this complex and dynamic interplay. Multichannel multimodality imaging including optics, CT, PET and MRI, are particularly promising because they can simultaneously sample multiple biomarkers. As the opportunities provided by imaging expand, mapping interconnected systems will help us decipher the complexity of cardiovascular disease and monitor novel therapeutic strategies.

Measuring quantitative distances are important for studying the structural properties of molecules at an atomic scale. Dipole-dipole coupling encodes for distance information between spin pairs. Additionally, the anisotropy of dipole-dipole coupling is also very sensitive to the sub-microsecond dynamics occurring in the molecules, and therefore can be used to estimate it. Rotational Echo Double Resonance (REDOR) and Correlation of Dipolar coupling and Chemical shift (DIPSHIFT) experiments are the most preferred experiments for measuring distances between a heteronuclear spin pair using Magic angle spinning (MAS) solid-state NMR. But these experiments can be used only for a small range of coupling strengths depending on the MAS frequency of the experiment. In the talk, I will discuss the latest developments we have made for measuring a wide range of coupling strengths using REDOR over a wide range of MAS frequencies. Further, I will also show that REDOR and DIPSHIFT are different realizations of a same experiment and this unification comes naturally out of our augmented REDOR sequence. Further, I will discuss a method to perform REDOR experiments with low radiofrequency amplitude pulses at MAS frequencies larger than 80~kHz. This method extends the application of REDOR and DIPSHIFT at very fast MAS frequencies, where the radiofrequency amplitude requirement becomes too high for nuclei other than 1H. Overall, the methods discussed here allow for measuring dipole-dipole coupling between heteronuclear spin-pairs over a wider range of MAS frequencies. References: 1. T. Gullion and J. Schaefer, Journal of Magnetic Resonance, 1989. 2. M. G. Munowitz et al., Journal of American Chemical Society, 1981. 3. M. Hong et al., Journal of Magnetic Resonance, 1997. 4. P. Schanda et al., Journal of Magnetic Resonance, 2019. 5. M. G. Jain et al., Journal of Chemical Physics, 2017. 6. M. G. Jain et al., Journal of Chemical Physics, 2019. 7. M. G. Jain et al., Journal of Magnetic Resonance, 2019.

Electron Paramagnetic Resonance (EPR) Imaging is a well-established method for the study of spatial distribution and local environment of electron paramagnetic centers and spin probes. One of the most important applications of modern EPR imaging is in vivo oximetry in which soluble spin probes with oxygen-dependent relaxation rates are used. Partial oxygen pressure (pO2) levels in tumors are major determinants of the response to cancer therapy. I will present the results of the in vivo oxygen guided radiation targeting study. This study combines pO2 images and conformal radiation delivery using 3D-printed blocks to achieve high precision treatment of tumor hypoxic areas. The study demonstrates that the dose to well-oxygenated tumor volumes in fibrosarcoma tumors in mice can be considerably reduced without compromising the outcome.

Energy transfer through the Förster mechanism, often referred to as FRET, depends critically on the overlap between the emission of the donor chromophore and the absorption of the acceptor chromophore. When photochromic molecules (molecular photoswitches) are isomerized between the two forms, the absorption spectra typically experience dramatic changes. Also, some photoswitches display emission exclusively in one isomeric form. This opens up the possibility to switch the capacity to act as both donor- and acceptor units, and hence, also to control energy transfer processes with concomitant changes in the fluorescence pattern. In addition to the abovementioned spectral features, the rate of the FRET process is highly dependent on the distance between the donor and the acceptor. This parameter can also be varied using molecular photoswitches, in the making/breaking of supramolecular complexes, which in turn dramatically changes the donor-acceptor distance and the FRET efficiencies. In this presentation, I will give examples of how the both these approaches can be used to tune the emissive properties of photochromic constructs. From trivial fluorescence “on-off” switching, via directional switching, to systems displaying full-color reproduction.

Due to the direct correlation among the physical properties and crystal structure of materials, study of the latter is crucial for fundamental understanding of the properties. In the era of nano-science, objects of interest are getting smaller and traditional single-crystal and powder X-ray diffraction methods cannot be applied for characterization of their atomic structures due to the unavailability of single crystals and/or small quantity and size of these crystals in the multiphase specimens. Thus, electron crystallography (EC) (which is defined as a combination of electron diffraction and imaging methods) is sometimes the only viable tool for the analysis of their structure. In the previous century, electron diffraction (ED) was considered to be unsuitable for structure determination due to the problems of data quality arising from dynamical effects. At the last decades, researchers have shown that influence of dynamical effects can be substantially reduced if beam precession (PED) is used and/or data collection is performed in the off-axis conditions - enabling solution of atomic structures with various complexity (from inorganics to proteins). Our group focuses on development and application of EC methods for structure solution of nano-sized precipitates and characterization of structural defects in steels and light alloys. This study is technologically essential since precipitates and defects dictate physical properties of these structural materials. It must be noted that, atomic structures of intermetallics were not solved previously using solely ED methods. Reason for that is in the nature of intermetallic compound's structures. Contrarily to other complex materials, the atomic distances and angles of intermetallics are not fixed and coordination polyhedra are usually unknown. Thus, structure solution of these compounds is harder to validate. In the present seminar, contribution of our group in the development of routine structure solution path for aluminides (as an example of intermetallics) will be presented. In addition, characterization of structural defects, influencing the performance of the studied materials, will be shown.

Our research uses chemistry principles to address questions of importance in life sciences and molecular medicine. This lecture will cover recent examples of emerging areas in our group in: (i) methods developed for site-selective chemical modification of proteins at cysteine, disulfide and lysine and their use to build stable and functional protein conjugates for in vivo applications [1–4] (ii) bioorthogonal cleavage reactions for targeted drug activation in cells [5,6] (iii) by identifying on- and off-targets for anti-cancer entities using our own machine intelligence platform, unveiling the underlying molecular mechanisms of target recognition and linking drug target binding to modulation of disease, we explore the use of natural products as selective cancer modulators [7] Recent Publications: 1. Bernardim B; Cal PMSD; Matos MJ; Oliveira BL; Martínez-Sáez N; Albuquerque IS; Corzana F; Burtoloso ACB; Jiménez-Osés G; Bernardes GJL* Stoichiometric and Irreversible Cysteine-selective Protein Modification using Carbonylacrylic Reagents. Nat. Commun. 2016, 7, 13128. 2. Martínez-Saez N; Sun S; Oldrini D; Sormanni P; Boutureira O; Carboni F; Compañón I; Deery MJ; Vendruscolo M; Corzana F; Adamo R; Bernardes GJL* Oxetane Grafts Installed Site-Selectively on Native Disulfides to Enhance Protein Stability and Activity In Vivo. Angew. Chem. Int. Ed. 2017, 47, 14963–14967. 3. Freedy AM; Matos MJ; Omar Boutureira O; Corzana F; Guerreiro A; Somovilla VJ; Rodrigues T; Nicholls K; Xie B; Jiménez-Osés G; Brindle KM; Neves AA; Bernardes GJL* Chemoselective Installation of Amine Bonds on Proteins Through Aza-Michael Ligation. J. Am. Chem. Soc. 2017, 139, 18365–18375. 4. Matos MJ; Oliveira BL; Martínez-Sáez N; Guerreiro A; Cal PMSD; Bertoldo J; Maneiro M; Perkins E; Howard J; Deery MJ; Chalker JM; Corzana F; Jiménez-Osés G; Bernardes GJL* Chemo and regioselective lysine modification on native proteins. J. Am. Chem. Soc. 2018, 140, 4004–4017. 5. Stenton BJ; Oliveira BL; Matos MJ; Sinatra L; Bernardes GJL* A Thioether-directed Palladium-cleavable Linker for Targeted Bioorthogonal Drug Decaging. Chem. Sci. 2018, 9, 4185–4189. 6. Sun S; Oliveira BL; Jiménez-Osés G; Bernardes GJL* Radical-mediated thiol-ene strategy for photoactivation of thiol-containing drugs in cancer cells. Angew. Chem. Int. Ed. 2018, DOI: 10.1002/anie.201811338. 7. Rodrigues T; Werner M; Roth J; da Cruz EHG; Marques MC; Akkapeddi P; Lobo SA; Koeberle A; Corzana F; da Silva Júnior EN; Werz O; Bernardes GJL* Machine intelligence decrypts β-lapachone as an allosteric 5-lipoxygenase inhibitor. Chem. Sci. 2018, 9, 6885–7018.

Due to the direct correlation among the physical properties and crystal structure of materials, study of the latter is crucial for fundamental understanding of the properties. In the era of nano-science, objects of interest are getting smaller and traditional single-crystal and powder X-ray diffraction methods cannot be applied for characterization of their atomic structures due to the unavailability of single crystals and/or small quantity and size of these crystals in the multiphase specimens. Thus, electron crystallography (EC) (which is defined as a combination of electron diffraction and imaging methods) is sometimes the only viable tool for the analysis of their structure. In the previous century, electron diffraction (ED) was considered to be unsuitable for structure determination due to the problems of data quality arising from dynamical effects. At the last decades, researchers have shown that influence of dynamical effects can be substantially reduced if beam precession (PED) is used and/or data collection is performed in the off-axis conditions - enabling solution of atomic structures with various complexity (from inorganics to proteins). Our group focuses on development and application of EC methods for structure solution of nano-sized precipitates and characterization of structural defects in steels and light alloys. This study is technologically essential since precipitates and defects dictate physical properties of these structural materials. It must be noted that, atomic structures of intermetallics were not solved previously using solely ED methods. Reason for that is in the nature of intermetallic compound's structures. Contrarily to other complex materials, the atomic distances and angles of intermetallics are not fixed and coordination polyhedra are usually unknown. Thus, structure solution of these compounds is harder to validate. In the present seminar, contribution of our group in the development of routine structure solution path for aluminides (as an example of intermetallics) will be presented. In addition, characterization of structural defects, influencing the performance of the studied materials, will be shown.

Transition-metal mediated bond cleavage and formation has made a great contribution in synthetic organic chemistry. A metal-ligand cooperativity often plays essential roles in the bond cleavage and formation reactions. Shvo and Casey studied the heterolytic cleavage/formation of H–H bond mediated by cyclopentadienone metal complexes with simultaneous oxidation/reduction of the central metal. Here in this presentation, this cooperativity is applied to the new type of bond cleavage/formation reactions such as C–O, C–H, and B–H Bonds.

A prion is a misfolded form of the cellular prion protein, PrPC. Although the role of PrP in neurodegeneration was established over 30 years ago, there is little understanding of the protein’s normal function, and how misfolding leads to profound disease. Recent work shows that PrPC coordinates the cofactors Cu2+ and Zn2+, and regulates the distribution of these essential metal ions in the brain. Moreover, these metals stabilize a previously unseen fold in PrPC, the observation of which provides new insight into the mechanism of prion disease. To date, Cu2+ coordination was thought to be limited to residues within the protein’s N-terminal domain. However, new NMR and EPR experiments suggest that histidine residues in the C-terminal domain assist in stabilizing the Cu2+-promoted PrPC fold. This talk will describe combined NMR, EPR, mutagenesis and physiological studies that provide new insight into the PrPC fold and function.

For some time, our group has been focused on the design, synthesis and application of derivatives of boron subphthalocyanines (BsubPcs), a macrocyclic molecule with chelated central boron atom. Our focal point has been and continues to be equally balanced between the basic and applied chemistry of BsubPcs, their application as light absorbing and electronic conducting materials in organic photovoltaics (OPVs)/solar cells. For this presentation I will outline how we have developed BsubPcs for their application in OPVs and other organic electronic devices. For OPVs, we have developed an approach to their development whereby their basic and applied chemistry is justified by a development cycle which includes their physical chemistry and characterization, their immediate integration into OPVs and based on their indoor stability are placed in the ambient environment to truly address their ultimate application in organic solar cells. Integrated into this cycle is a computational modeling methodology that is used to screen potential BsubPcs for their application in organic electronic devices including OPVs/organic solar cells. Most recently we have identified a pathway to BsubPcs whereby all carbons are bio-sourced and I will highlight how the computational model justified the time and resource commitment to their synthesis and development. In addition to BsubPcs, we have taken an equal approach to extended -conjugated derivatives of BsubPcs, boron subnaphthalocyanines (BsubNcs); BsubNcs being unique and beneficial materials for OPV application. We have shown that BsubNcs actually become randomly chlorinated during their synthetic preparation and actually then form a mixed alloy composition of chlorinated materials, which we have designated as Cl-ClnBsubNcs. The mixed alloy composition is unique, and has been determined to be a mixture of 24 (more or less) chlorinated BsubNcs despite being a mixture that uniquely forms single crystals. The formation of single crystals is enabled by the chlorine atoms occupying vacancies within the solid state structure, the vacancies being the so-called “bay position” of the BsubNcs structure. During this presentation I will highlight how odd the mixed alloy composition of organic materials is and how hard it has been to separate the mixed alloyed composition. I will also highlight how we are moving forward with purposefully making mixed alloyed compositions of our macrocyclic compounds BsubPcs and BsubNcs fully justified by the potential performance increase in organic solar cells. Co-authors/investigators will be identified during this presentation. #-- Some Relevant References. [1] “Outdoor Performance and Stability of Boron Subphthalocyanines Applied as Electron Acceptors in Fullerene-Free Organic Photovoltaics.” Josey, D.; et al, ACS Energy Lett., 2017, 2(3), 726–732. DOI: 10.1021/acsenergylett.6b00716. [2] “Boron Subphthalocyanines as Electron Donors in Outdoor Lifetime Monitored Organic Photovoltaic Cells.” Garner, R.K.; et al, Solar Energy Materials and Solar Cells, 2018 176, 331-335. DOI: 10.1016/j.solmat.2017.10.018 [3] “8.4% efficient fullerene-free organic solar cells exploiting long-range exciton energy transfer” Cnops, K.; et al., Nature Comm., 5, Article number: 3406, DOI:10.1038/ncomms4406. [4] “The mixed and alloyed chemical composition of chloro-(chloro)n-boron subnaphthalocyanines dictates their physical properties and performance in organic photovoltaics.” Dang, J.D.; et al, J. Mat. Chem. A., 2016, 4, 9566-9577. DOI: 10.1039/C6TA02457B [5] “Phenoxy-(chloro)n-boron subnaphthalocyanines; alloyed mixture, electron-accepting functionality, enhanced solubility for bulk heterojunction organic photovoltaics” Dang, J.D.; et al, ACS Omega, 2018, 3(2), 2093–2103. DOI: 10.1021/acsomega.7b01892. [6] “The Mixed Alloyed Chemical Composition of Chloro-(chloro)n-Boron Subnaphthalocyanines Dictates Their Performance as Electron-Donating and Hole-Transporting Materials in Organic Photovoltaics” Garner, R.K.; et al, ACS Appl. Energy Materials, 2017, 1(3), 1029-1036. DOI: 10.1021/acsaem.7b00180. [7] "Outdoor Stability of Chloro-(Chloro)n-Boron Subnaphthalocyanine and Chloro-Boron Subphthalocyanine as Electron Acceptors in Bilayer and Trilayer Organic Photovoltaics" Josey, D.; et al, ACS Applied Energy Materials, 2019, 2(2), 979–986. DOI:10.1021/acsaem.8b01918

We can watch crystals grow in the electron microscope by adding atoms one at a time onto a clean surface. The movies tell us about kinetics and thermodynamics but can also be entertaining, frustrating, or both at the same time. I will attempt to share the joy of this type of “in situ” microscopy as we aim to understand how atoms assemble into nanowires or nanocrystals and use the information to control the formation of more complicated nanostructures with new properties

Nuclear magnetic resonance (NMR) spectroscopy is a powerful analytical tool for the characterization of protein structure and intermolecular interactions. However, NMR is not readily applicable to determine fast structural changes and weak interactions between molecules because of low signal sensitivity and time requirements to record multi-dimensional NMR spectra. To overcome these limits, the hyperpolarization technique of dissolution dynamic nuclear polarization (D-DNP) is combined with NMR. Not all molecules can be directly hyperpolarized. Instead, polarization transfer from hyperpolarized small molecules to a target of interest can be utilized as a means of obtaining polarization, as well as for detecting intermolecular interactions between these molecules Here, hyperpolarized water-assisted NMR spectroscopy was developed to measure intermolecular interactions with water. Firstly, the use of DNP hyperpolarization was demonstrated for the accurate determination of intermolecular cross-relaxation rates between hyperpolarized water and fluorinated target molecules.[1] Because hyperpolarized water acts as a source spin with a large deviation of the population from the equilibrium, the 19F signal on the target molecules is enhanced through NOE, allowing obtain an entire NOE buildup curve in a single, rapid measurement. When the hyperpolarized water-assisted NMR experiment is applied to a protein, water hyperpolarization can be transferred to amide protons on the protein through proton exchange. Further, this polarization spreads within the protein through intramolecular NOE to nearby protons including aliphatic groups.[2] By utilizing this polarization transfer, this method extends to measure enhanced 2D NMR spectra of the protein under folded and refolding conditions.[3] With the ability to rapidly measure protein signals that were enhanced through transferred polarization from hyperpolarized water, NMR spectra can be acquired within the timescale of the protein folding. Compared to the folded protein experiment, signals attributed to exchange-relayed NOEs are not observable in the refolding experiment (Figure 1b). These differences are explained by the absence of long-range contacts with nearby exchangeable protons such as OH protons

The recent rapid, global growth of photovoltaics has moved scientific research frontiers for solar energy conversion towards new opportunities including i) ultrahigh efficiency photovoltaics (η > 30%) and ii) direct synthesis of energy-dense chemical fuels from sunlight, including hydrogen and products from reduction of carbon dioxide. I will illustrate several examples of how design of materials for light harvesting, charge transport and catalytic selectivity can enable advances in electricity and fuel synthesis. Photonic design has opened new directions for high efficiency photovoltaics and luminescent solar concentrators. Semiconductors coupled to water oxidation and reduction catalysts have enabled approaches to photoelectrochemical solar-to-hydrogen generation with >19% efficiency using artificial photosynthetic structures. Solar-driven reduction of carbon dioxide presents both an enormous opportunity and challenge because of the need for selectivity in generating useful multi-carbon products by multiple electron and multi-proton transfer steps. Present work and future directions in selective photocatalytic and photo-electrocatalytic materials for artificial photosynthesis aimed at catalytic reduction of carbon dioxide will be discussed.

Halide Perovskites, HaPs, make up a group of semiconducting materials with excellent light absorption and good electrical charge transport properties, which is remarkable given their low-temperature solution preparation. In my Ph.D. research, I investigated fundamental optoelectronic properties of HaP semiconductors to elucidate dominant charge transport mechanisms, with emphasis on providing design tools for high-efficiency solar cells to help transform the renewable, solar energy landscape. I will show how I characterized Fermi level positions and studied the self-doping mechanism of different HaP materials by using a suite of in situ measurements. My main conclusion was that halide vacancy defects (surface, interface, or bulk) and electron sharing between oxygen and the HaP surface, drive Fermi level changes. The former had been postulated but not experimentally shown, until my work. By elucidating the electric field distribution and photovoltage losses I could show that Br-based HaP device efficiency is limited mainly by a (relatively) high defect density at the anode/semiconductor interface.

The use of proteomics in the clinical arena has been traditionally hampered by low sample throughput and by difficulties in quantifying proteins in complex proteomes in an absolute manner. The use of ultrasonic energy to speed complex proteomics workflows for protein quantification along with thea advent of High Resolution Mass Spectrometry have made possible to treat and to analyze tens of samples a day, thus making mass spectrometry-based clinical proteomics a modern practical tool to be explored.

We, humans and animals, feel the outside world thanks to our 5 senses. We hear, we see, we smell, we touch, and we taste. The success of our lives often depends on how sharp our senses are. In a scientific environment, sensing and feeling is also important. In chemistry, in biology, in medicine, in forensics, as in other areas, feeling, recognising, is crucial. In the present seminar, I will show some examples of the use of chromophores such as porphyrins, emissive peptides, rhodamines, liquid crystals-based metal complexes, fluorescein and others, free or supported in polymers, paper, and gold, silver, platinum nanoparticles, or messoporous structured nanomaterials for hunting and capture of molecules, ions and biomarkers for Proteomics Applications.

The last five years have seen major reductions in silicon solar module prices, with these dropping at a compounded rate approaching 20%/year over this period, with even more dramatic reductions in bids for bulk electricity supply through Power Purchase Agreements, to values as low as US$16.88/MWh. On the technology front, there have been substantial improvements in module energy conversion efficiency through displacement of established cell technology by the UNSW-invented and -developed PERC cell, complemented by the introduction of multi-busbar, half-cell and shingled modules. The introduction of PERC cells also allows low-cost fabrication of bifacially responsive modules, set to further boost effective efficiencies. These developments position photovoltaics to make a major impact on global CO2 omissions. A recent international study describes a technological path to a zero-carbon future by 2050 by transformation across all major energy sectors including not only electricity, but also heat, transport and industrial processes. This transformation is driven primarily by solar, with 63TW capacity calculated as required globally by this date, complemented by 8TW of wind, in the process creating 35 million direct energy jobs.

In the history of many families, all that remains about the fate of an ancestor for whom all traces were lost are rumors, often in conflicting versions. One of the most gratifying pleasures of a genealogical quest is to unveil the true story. Two examples taken from the lecturer’s personal history will demonstrate this.

Currently, more than 40 gigatonnes of CO2 are released annually into the atmosphere as a result of fossil fuel combustion, causing ocean acidification and climate unpredictability. Anthropogenic CO2 emission is seemingly hard to diminish in the near future and, therefore, CO2 -capture and sequestration or CO2 -functionalization can be viable solutions to address this issue. To use CO2 as a chemical feedstock, namely as a C1 building block, it is essential to equip the process with a nucleophilic catalyst or a highly active reagent, as exemplified by Grignard carboxylation reactions and some recent progress in metal-catalyzed reactions. In this seminar, I will display how we can utilize CO2 not only as a chemical feedstock and a catalyst but also as a stimulus for a desalination process. The obtained knowledge in CO2 activation and desalination will be beneficial in supramolecular chemistry, biology, CO2functionalization catalysis and CO2 sequestration processes.

Surface supported single magnetic atoms, the so-called "single-atom magnets", open new opportunities in a quest for t he ultimate size limit of magnetic information storage. Initially, the research mainly focused on 3d-atoms on surfaces. Recently, the attention was turned to the 4f-atoms, culminating in the experimental discovery of magnetically stable Ho atom on MgO(001) substrate, and Dy atom on graphene/Ir(111). I address the electronic and magnetic character of 4f-atoms on metal and Graphene substrate making use of a combination of the DFT+U with the exact diagonalization of Anderson impurity model (DFT+U+ED). The spin and orbital magnetic moments of Dy@Ir(111) and Dy/Graphene/Ir(111) are evaluated and compared with experimental XMCD data. The magnetic anisotropy energy is estimated, and the magnetic stability is discussed. The role of 5d-4f interorbital exchange polarization in modification of the 4f-shell energy spectrum is emphasized.

A comprehensive study showing a trio correlation between cell mechanics, phagocytic capacity, and cancer aggressiveness is presented. Mechanical properties of particles are shown to have a critical effect on the interactions with malignant cancer cells. Our findings offers new directions for mechanical based specificity in cancer treatment, and could lead to uptake measurement as a diagnostic tools for precision medicine.

EPR spectroscopy can be used to measure nanometre-scale distances within biomolecules and other soft matter, through determining the dipolar coupling between paramagnetic centres. These can be placed site-specifically within the molecules-of-interest as spin labels. Some experiments that measure the dipolar coupling will be introduced, and results including new spin labels and applications of the methodology will be discussed.

Thermal motions of atoms is an ever-present phenomenon in all of solid state physics. Phonons, quanta of heat, is the quasiparticule used to describe thermal motion in solids. Under normal conditions phonons are the dominant mechanism that govern transport and the largest contribution to entropy. I want to understand how phonons evolve in time, temperature, and how they behave when they interact strongly with each other or other quasiparticles. The inherent disorder in thermal motions makes theoretical predictions challenging. I will present methodological developments in finite temperature first principles simulations, specifically targeting strongly anharmonic systems. The method employs model Hamiltonians that explicitly depend on temperature. I will present applications pertaining to thermal conductivity, inelastic neutron spectra and phase stabilities, reproducing non-trivial temperature dependencies.

Cell penetrating peptides have a unique potential for targeted drug delivery. While ATP-driven endocytosis is known to play a major role in their internalization, there has been also ample evidence for the importance of passive translocation for which the direct mechanism, where the peptide is thought to directly pass through the membrane via a temporary pore, has been widely advocated. In this talk, I will question this view and demonstrate that arginine-rich cell penetrating peptides can instead enter vesicles and cells by inducing multilamellarity and fusion, analogously to the action of calcium ions. Allolio C., Magarkar A., Jurkiewiczf P., Baxová K., Javanainen M., Mason P.E., Sachl R., Cebecauer M., Hof M., Horinek D., Heinz V., Rachel R., Zieglerg C.M., Schrofel A., Jungwirth P.: Arginine-rich cell-penetrating peptides induce membrane multilamellarity and subsequently enter via formation of a fusion pore. Proceedings of the National Academy of Sciences USA 115 (2018) 11923.

In order to make modelling of aqueous electrolytes more accurate, we explore the recently suggested approach for effectively accounting for electronic polarization effects using ionic charge rescaling. Based on this approach we develop a new and accurate parametrization of ions. Comparison to neutron scattering and ab initio molecular dynamics simulations demonstrates that the charge scaling approach allows for an accurate description of concentrated aqueous salt solutions including divalent ions. The present approach should thus find broad use in efficient and accurate modelling of polyvalent ions in aqueous environments, such as those encountered in biological and technological applications.

Magnetic Resonance Imaging (MRI) provides excellent quality images of soft tissues and is an established modality for diagnosis, prognosis and monitoring of various diseases. Majority of MRI scans in clinical practice today report on anatomy, morphology and sometimes physiology. The new area of active studies is aimed at developing MRI contrast methods for the detection of the events at the microstructural and molecular level employing endogenous properties. Here, we will discuss methods that employ single- and multi-frequency saturation to detect events on microstructural and molecular level. First, we will describe principles and translational aspects of Chemical Exchange Saturation Transfer1(CEST). CEST employs selective saturation of the exchanging protons and subsequent detection of the water signal decrease to create images that are weighted by the presence of a metabolite or pH2. We will describe aspects of translating CEST to reliable clinical applications and discuss its potential uses in human oncology, specifically breast cancer. Second, we will describe a method called inhomogeneous Magnetization Transfer3 (ihMT), which employs dual-frequency saturation to create contrast originating from the residual dipolar couplings and thus specific to microstructure. We will focus on the application of ihMT to the detection of myelin in brain and spinal cord. Finally, we will discuss a novel exchange-sensitive method based on the balanced steady-state free precession (bSSFP) sequence as an alternative way for chemical exchange detection (bSSFPX4). Using an effective field description, similarities between bSSFP and CW application can be explored and utilized for in-vivo MRI contrast. [1] K. Ward, et.al., JMR,143,79-87 (2000). [2] J. Zhou, et.al., Nature Medicine, 9,1085-1090 (2003). [3] G. Varma, et.al., MRM, 73, 614-622 (2015). [4] S. Zhang, et.al., JMR, 275, 55-67 (2017).

Radio frequency (RF) coil design for ultra-high field MRI scanners is an active field of research. We have recently developed an 8-channel transmit, 32-channel receive 7T head coil at the University of Glasgow. We focused on an open-faced design to make the setup less claustrophobic and more acceptable in a clinical environment. Furthermore, the coil can be used in both the scanner modes. I will also present our internal validation process which allows home-built RF coils to be used in vivo.

While octahedral tilting or B atom displacements as a single repeated structural motif are well known in perovskites, we find that removing the standard restriction to such a minimal unit cell size leads in some perovskites to the formation of a ‘polymorphous network’, manifesting a distribution of different tilt angles and different B-atom displacement in different octahedra. The distribution of local motifs emerges already from the (density functional) minimization of the static, T=0 internal energy of a large supercell, constrained to have the global cubic lattice vectors. This a-thermal distribution represents a correlated set of displacements and is very different from the time-dependent uncorrelated entropic thermal disorder calculated by Molecular Dynamics, or from the single sharp monomorphous values of these deformation parameters . This suggests that the widely discussed single formula unit cubic Pm-3m structure of halide perovskites does not really exist, except as a macroscopically averaged fictitious structural model. Because X-ray diffraction has a rather long coherence length, such polymorphous systems were often fit in structure refinement models by a macroscopically averaged (“fictitious monomorphous”) cubic Pm-3m unit cells. Significantly, compared to the monomorphous assumption, the cubic polymorphous network affects Pair Distribution Function (PDF), total energies, up to 300% larger band gaps, leads to the reversal of the predicted sign of the mixing enthalpies of the solid solutions from negative (ordering-like; not seen experimentally) to positive (experimentally observed phase-separating).Also, the polymorphous networks have a much larger (by ~50%) calculated dielectric constant, yet a relatively narrow energy range of vacancy transition levels and sharp absorption onset.defect physics. The polymorphous approximant could thus serve as a useful practical structure to use with standard band structure approaches to predict properties, replacing the fictitious monomorphous structures .

Low-dimensional nanostructures, which have at least one nano-scale length scale and at least one long length scale and include technologically promising cases like layered materials and nanowires, can exhibit unusual van der Waals dispersion forces. These manifest via "non-additive" contributions to the dispersion energy, which are excluded from models, such as D3, which sum over contributions across different constituent atoms. This talk will discuss the origin, role, and general weirdness of such effects. We will discuss the Dobson scheme for describing such effects and show some systems where conventional approaches to dispersion miss important qualitative and quantitative physics. New methods which capture some or all of these effects will be described. The importance of dispersion forces will be contextualised. Finally, we will digress into a new frontier of method development – easy modelling of low-lying excited states.

Synthetic methods based on sol-gel chemistry are attractive solution-based routes to many simple and complex materials. The non-hydrolytic procedures are viable alternatives to classical aqueous techniques and these condensation reactions are inherently suitable for fabrication of mixed-metal and multimetallic oxidic and hybrid inorganic-organic systems. We developed novel non-hydrolytic sol-gel routes to several classes of porous xerogels, such as silicophosphates and -phosphonates, aluminophosphates, Al, Ti, Zr, and Sn silicates, hybrid aromatic organosilicates, and organosilicophosphates. The polycondensation reactions are based on elimination of small molecules, such as trimethylsilyl ester of acetic acid, dialkylacetamides, silylamines, ethers or alcohols. These elimination reactions provide microporous xerogels with high surface areas. Control of porosity and pore size is achieved by several methods, such as choice of suitable precursors, application of bridging groups, or addition of Pluronic templates. Residual organic groups on the surface allow for chemical modification and anchoring of various groups. Calcination in air provides xerogels that are stable at temperatures up to 500 C and show superior catalytic activity and selectivity in various catalytic reactions. The prepared xerogels were characterized by solid-state 13C, 27Al, 29Si, 31P NMR, IR, surface area analysis, DRUV-vis, TGA and XRD

Reactive Intermediates & Group Transfer Reactions. We design and synthesize molecular precursors that can be activated by a stimulus to release a small molecule of interest. The molecular precursors themselves are isolated as crystalline solids; they are typically soluble in common organic solvents and can be weighed out and used as needed. For example, the molecule P2A2 (A = anthracene or C14H10) is a molecular precursor to the diatomic molecule P2. Compounds having the formula RPA serve to transfer the phosphinidene (PR) group either as a freely diffusing species (R = NR’2, singlet phosphinidene) or else by inner sphere mechanisms (R = alkyl, triplet phosphinidene). Using the RPA reagents we are developing reactions analogous to cyclopropanation and aziridination for delivery of the PR group to olefins with the formation of three-membered P-containing rings, phosphiranes. Metaphosphates and Phosphorylating Methodology. Crystalline metaphosphate salts with lipophilic counter cations are useful starting materials applicable in polar organic media. “Metaphosphate” refers to the inorganic ion PO3(-) which, unlike its chemical cousin, nitrate, exists not as a monomeric species but rather as oligomeric rings: [(PO3)n]n-. These cyclic phosphates can be converted into electrophilic phosphorylating agents (a) by treatment with peptide coupling reagents, or (b) by conversion into their crystalline acid forms and subsequent dehydration. Such activated cyclic phosphates can be used directly for oligophosphorylation of C, N, and O nucleophiles. Phosphorylation of the Wittig reagent leads to a new phosphorus ylide with a cyclic phosphate as the C-substituent and a non-hydrolyzable P-C bond, allowing for conjugation of oligophosphate groups to a biomolecule of interest by aldehyde olefination. Sustainable Phosphorus Chemistry. The industrial “thermal process” by which the raw material phosphate rock is upgraded to white phosphorus is energy intensive and generates CO2. We seek alternative chemical routes to value-added P-chemicals from phosphate starting materials obtained either by the agricultural “wet process” or by phosphorus recovery and recycling from waste streams. Trichlorosilane is a high production volume chemical for its use in the manufacture of silicon for solar panels. We show that trichlorosilane is a reductant for phosphate raw materials leading to the bis(trichlorosilyl) phosphide anion [P(SiCl3)2]- as a versatile intermediate en route to compounds containing P-C bonds.

Structural hierarchy is a powerful design concept where specific geometric motifs are used to influence material structure across multiple size regimes. These complex levels of organization are typically achieved in the laboratory by conceptually breaking a material down into the smallest components that can be manipulated (e.g. individual molecules, macromolecules, or nanoparticles), and manipulating the thermodynamics of chemical bonding between those components to control how they build up into larger length scale patterns. Conversely, complex assemblies in natural systems are commonly achieved through a more holistic approach where assembly behaviors at the molecular, nano, and macroscopic scales are interlinked. This means that not only does structural information contained in molecular building blocks filter upwards to dictate material form at the nano to macroscopic levels, but also that the environment created by the larger length scale features can affect the behavior of individual components. Here, we will discuss two different methods to synthesize materials in a systems-focused approach that mimics nature's ability to general complex structural motifs across a wide range of size regimes. The first uses nanoscale design handles to deliberately control the multivalent assembly of particle-grafted supramolecular binding moieties, where control over both molecular and nanostructure of material building blocks is then used to manipulate the mesoscale structure of the resulting materials. The second uses macroscopic interfaces to dictate the assembly behavior of DNA-grafted nanoparticles, generating superlattice architectures with controlled sizes, shapes, and orientations. Together, these techniques allow for systems-level approaches to materials design, expanding our ability to program hierarchical ordering at the molecular, nano, and macroscale simultaneously.

The talk will describe nonlinear rheology in extreme conditions that change fluid structure and flow mechanisms. Elongational flow of entangled polymers produces near complete molecular alignment but only changes the viscosity by an order of magnitude and does not destroy the confining tube. A transition in the mechanism of shear thinning in lubricants from alignment to thermal activation is shown to be generic and allows simulations to examine whether the viscosity diverges at a finite glass transition temperature.

The synthesis and the design of complex molecular scaffolds with defined properties present central challenges in current chemical research. Such molecules can provide access to novel therapeutics, catalysts and materials. Often, it is essential for these scaffolds to adopt defined three-dimensional structures. Preferably, the degree of flexibility in these systems can be fine-tuned in a defined and controllable manner. The folding properties of peptides and proteins provide an excellent basis for the design of molecules with defined structural properties, in particular when combined with non-natural small molecular scaffolds. The research of the Grossmann lab centers around the synthesis of peptide-derived molecules and the engineering of proteins using organic chemistry approaches. The lecture will highlight design principles and synthetic strategies that enable the conformational control of relatively small and flexible peptidomimetics[1,2] as well as large and globular enzymes.[3] In addition, reversible constraints that allow the design of peptide-based molecular switches[4] will be presented. References: [1] A Glas et al. Angew. Chem. Int. Ed. 2014, 53, 2489–2493 [2] P Cromm et al. Nature Commun. 2016, 7, 11300. [3] M Pelay-Gimeno et al. Angew. Chem. Int. Ed. 2018, 57, 11164-11170. [4] C Mueller et al. Angew. Chem. Int. Ed. 2018, 57, 17079-17083

Block copolymer-guided assembly of nanoparticles leads to the formation of nanocomposites with periodic arrangement of nanoparticles, which are important for applications such as photonic devices and sensors. However, linear block copolymers offer limited control over the internal arrangement of nanoparticles inside their hosting domains as well as the long-range ordering of the entire nanocomposite film. The first part of the talk will focus on the molecular level: how the chemical design of the polymeric system – both compositional and architectural – could be used to tailor chemical interactions and manipulate chain conformation, which, in turn, influence the local nanoparticle distribution inside the domains they segregate in. In the second part I will show how the utilization of topographically patterned substrates could be used not only to align block copolymer domains along a macroscopic coordinate but also to obtain isolated patterns on non-regular features.

Grain boundaries (GBs) are the 2D interfaces between crystals of the same material with different orientations. The dynamics of GBs is central to both microstructure evolution and the mechanics of polycrystals. GB dynamics are largely controlled by the motion of line defects that are constrained to lie in the GB. These line defects, known as disconnections, have both dislocation character (Burgers vector) and step character (step height). Possible Burgers vectors and step heights are completely determined by crystallography (i.e., crystal structure and the relative orientations of the two grains). In this talk, I will discuss disconnections, their crystallography, their nucleation and motion, and present a statistical mechanics-based description of a wide range of GB properties based on disconnection dynamics. In particular, I will discuss the thermal roughening of GBs, the migration of GBs, GB shear coupling, and how GBs interact with with applied stresses and compare these predictions with both molecular dynamics and experimental results. I will end by describing the remaining challenges in developing a quantitative approach to the microstructure evolution of polycrystalline materials.

Shape transitions in developing organisms can be driven by active stresses, notably, active contractility generated by myosin motors. We study the contraction and buckling of actomyosin networks isolated from bounding surfaces as a model system for studying shape transitions in developing tissues. This system offers a well-controlled way to study the role of physical constraints and boundary conditions mechanically induced spontaneous shape transition.

The detection of spectroscopically silent analytes in water is often accomplished by utilization of reactive probes that form chromophoric analyte-dye conjugates. Unfortunately, similar but distinctly different analytes usually do not provide unique spectroscopic features, such that chromatographic separation steps have to be employed, causing significant additional costs and hinder applications. Supramolecular indicator-dye displacement assays can overcome certain limitations of reactive-probes, e.g., they allow for an in situ detection of even non-functionalizable analytes and are of great utility for reaction monitoring. However, their analyte differentiation capabilities are again restricted. Here, we present new strategies involving supramolecular sensing ensembles that allow for improved analyte differentiation through spectroscopic fingerprints. We show that this strategy is applicable to both non-covalent analyte-receptor binding schemes and to reactive-probe assays.

Since the isolation of graphene in 2004, atomically-thin quasi-two-dimensional (quasi-2D) materials have proven to be an exciting platform for both applications in novel devices and exploring fundamental phenomena arising in low dimensions. This interesting low-dimensional behavior is a consequence of the combined effects of quantum confinement and stronger electron-electron correlations due to reduced screening. In this talk, I will discuss how the optical excitations (excitons) in quasi-2D materials, such as monolayer transition metal dichalcogenides and few-layer black phosphorus, differ from typical bulk materials. In particular, quasi-2D materials are host to a wide-variety of strongly-bound excitons with unusual excitation spectra and massless dispersion. The presence of these excitons can greatly enhance both linear and nonlinear response compared to bulk materials, making them ideal candidates for optoelectronics and energy applications. Moreover, due to enhanced correlations and environmental sensitivity, the electronic and optical properties of these materials can be easily tuned. I will discuss how substrate engineering, stacking of different layers, and the introduction or removal of defects can be used to tune the band gaps and optical selection rules in quasi-2D materials.

Simple 2-dimensional cut and fold patterns can be transformed into 3-dimensional shapes upon stretch-ing. We use this simple approach to develop mechanical metamaterials with several interesting proper-ties and applications. I will describe ways of tuning properties via geometric structure, and discuss ex-amples of how this can be used to achieve superior performance in mechanics, photonics, electronics, sensors, and other areas. References: “Dynamic kirigami structures for integrated solar tracking.” Nature Comm. 6, 8092 (2015) “A kirigami approach to engineering elasticity in nanocomposites through patterned defects.” Na-ture Mater., 14 (2015) 785 “An Electric Eel-Inspired Artificial Soft Power Source from Stacked Hydrogels.” Nature, 552 (2017) 214

One-dimensional materials represent an attractive class of nanostructures, mainly because of their geometry which inherently implies applications such as electrodes for sensing purposes or conduction channels in nanoscale electronics. Different mechanisms may be utilized to prepare nanowires, e.g. stress-driven one-dimensional diffusion, metal-catalyzed growth (VLS) etc. The most important role in identifying and description of the growth mechanisms is played by real-time microscopies, mostly TEM. However, although very powerfull in terms of image resolution, TEM is also limited in use, especially because of very strict sample geometry requirements. In this seminar talk, I will present our real-time in-situ scanning electron microscopy experiments of nanowire growth. Two different material systems will be presented – germanium nanowires catalyzed by Au nanoparticles and WOx nanowires. As for the latter case, our experiments reveal a very unusual oxidation mechanism of tungsten disulfide nanotubes, resulting in tungsten oxide nanowire formation. The talk will summarize studies on quasi-1D systems conducted at IPE and CEITEC BUT.

Self-assembly of block copolymers (BCP) is a well-known method for nanostructure fabrication at the 5-50 nm scale. Recently, sequential infiltration synthesis (SIS) was developed from atomic layer deposition (ALD) chemistry for selective growth of inorganic materials within polymers. In this talk, I will discuss SIS mechanism and growth process development as well as our work on combining BCP self-assembly with SIS for nanoparticle structuring, 3D imaging with TEM tomography, ultrafiltration membranes, and advanced 3D nanofabrication.

We use a local magnetic imaging technique, scanning SQUID microscopy, to map the spatial distribution of electronic states near surfaces and interfaces. We track conductivity, superconductivity and magnetism in systems undergoing phase transitions, where the local picture is particularly meaningful. I will describe two measurements: At the superconductor-insulator transition in NbTiN we map superconducting fluctuations and detect a non-trivial behavior near the quantum critical point. Near the metal to insulator transition at the 2D LaAlO3/SrTiO3 interface, we find that the conduction landscape changes dramatically and identify the way different types of defects control the behavior.

The seminar summarizes three recent studies (1,2,3) since that share some common elements: they concern porous materials and the method used is NMR spectroscopy. Yet, the aims differ. In the first study (1), the unknown is the pore structure. In particular, pore structure in hydrogels is difficult to access as water cannot be removed without affecting the pores and in the presence of water the well-honed gas sorption and mercury porosimetries just do not work. The method we invented to remedy this situation is called size-exclusion quantification (SEQ) NMR and it can be seen as the multiplexed analogue of inverse size exclusion chromatography. In effect, we sample by diffusion NMR the size distribution in a polydisperse polymer solution before and after it had been equilibrated with a porous matrix. Size-dependent polymer ingress reveals the pore structure. The method has several advantages over possible alternatives, not least its speed. In the second study (2), we sample the self-diffusion of neat water and other molecules like dimethyl sulfoxide (DMSO) and their mixtures by NMR diffusion experiments for those fluids imbibed into controlled pore glasses (CPG, pore size range 7.5 to 73 nm). Their highly interconnected structure is scaled by pore size and exhibits pore topology independent of size. Relative to the respective diffusion coefficients obtained in bulk phases, we observe a reduction in the diffusion coefficient that is independent of pore size for the larger pores and becomes stronger toward the smaller pores. Geometric tortuosity governs the behavior at larger pore sizes, while the interaction with pore walls becomes the dominant factor toward smaller pore diameters. Deviation from the trends predicted by the popular Renkin equation and variants (4) indicates that the interaction with the pore wall is not just a simple steric one. In the third study (3), the porous material is hydrated cellulose. In that matrix, we identify by using 2H MAS NMR two different groups of water molecules being in slow exchange with each other. Water molecules in one of the groups exhibit anisotropic molecular motions with a high order parameter. Based on, among other things, the observed behavior with increasing vapor pressure, we argue that this water is an integral structural element of the cellulose fibril, that itself is an aggregate of the basic units, the cellulose nanofibrils.

For the purpose of identifying novel absorber materials based on experimental or computational material screening, it is useful to identify the basic ingredients required to make a good solar cell out of the combination of different absorber and contact materials. Figures of merit are needed that quantify whether a certain material is likely to perform well as a solar cell. To answer the question, which parameters are most important, we look into the key properties of good solar cells such as high absorption coefficient, mobility and charge carrier lifetime and study their interdependences and how they determine the efficiency at different thickness of the solar cell. Finally, we study some microscopic parameters such as the effective mass or electron-phonon coupling in a device to identify key microscopic properties that are likely to lead to a combination of high absorption, high mobilities and long lifetimes and thereby high photovoltaic efficiencies

The idea that complex liquid-air interfaces laden with surfactants, colloids, or polymer molecules, possess rheological properties that differ from those of the bulk sub-phase has been suggested 150 years ago. Yet, even today we are still struggling with the means to properly measure these properties. In this talk we will first explore the reasons to worry at all about the properties of the interface, examine some of the consequences of interfacial rheology, and revisit a century old technique - the unjustifiably named “Langmuir trough”, pointing out some experimental peculiarities.

The talk is devoted to the study of the light-matter interaction in the nonlinear regime using three different cavity quantum electrodynamics (CQED) systems. The matter under study is a Josephson flux qubit in the first experiment [1], a spin ensemble of diphenylpicrylhydrazyl (DPPH) molecules in the second one, and different spin ensembles in a diamond lattice in the third one [3]. In all three experiments the matter under study interact with photons (light) confined in a superconducting microwave resonator (cavity). A variety of nonlinear effects are explored, including super-harmonic resonances, multi-photon resonances, effective cavity heating and cooling and motional narrowing induced by quantum-jumps. The effect of nonlinearity on spin detection sensitivity will be discussed. 1. Eyal Buks, Chunqing Deng, Jean-Luc F.X. Orgazzi, Martin Otto and Adrian Lupascu, Phys. Rev. A 94, 033807 (2016). 2. Hui Wang, Sergei Masis, Roei Levi, Oleg Shtempluk and Eyal Buks, Phys. Rev. A 95, 053853 (2017). 3. Nir Alfasi, Sergei Masis, Roni Winik, Demitry Farfurnik, Oleg Shtempluck, Nir Bar-Gill and Eyal Buks, Phys. Rev. A 97 (2018).

Atomically-resolved imaging of materials has become the mainstay of modern materials science, as enabled by advent of aberration corrected scanning transmission electron microscopy (STEM). However, the wealth of quantitative information contained in the fine details of atomic structure or spectra remains largely unexplored. In this talk, I will present the new opportunities enabled by physics-informed big data and machine learning technologies to extract physical information from static and dynamic STEM images. The deep learning models trained on theoretically simulated images or labeled library data demonstrate extremely high efficiency in extracting atomic coordinates and trajectories, converting massive volumes of statistical and dynamic data into structural descriptors. I further present a method to take advantage of atomic-scale observations of chemical and structural fluctuations and use them to build a generative model (including near-neighbor interactions) that can be used to predict the phase diagram of the system in a finite temperature and composition space. Similar approach is applied to probe the kinetics of solid-state reactions on a single defect level and defect formation in solids via atomic-scale observations. Finally, synergy of deep learning image analytics and real-time feedback further allows harnessing beam-induced atomic and bond dynamics to enable direct atom-by-atom fabrication. Examples of direct atomic motion over mesoscopic distances, engineered doping at selected lattice site, and assembly of multiatomic structures will be demonstrated. These advances position STEM towards transition from purely imaging tool for atomic-scale laboratory of electronic, phonon, and quantum phenomena in atomically-engineered structures.

Anna McConnell, Otto Diels Institute of Organic Chemistry, Christian-Albrechts-Universität zu Kiel The supramolecular toolbox enables the self-assembly of supramolecular architectures from relatively simple building blocks through reversible, weak non-covalent interactions. Supramolecular architectures with increased complexity are appealing targets for not only the synthetic challenge but also for the potential to access new types of chemistry and functionality. Efforts towards increasing the complexity of both the supramolecular architecture and stimuli-responsive behaviour[1] in dynamic covalent and metal-organic cage systems will be presented. In one approach, the post-assembly reduction of achiral iminoboronates gives access to three isomeric products containing two stereogenic centres and two of these products interconvert through unusual lability of the covalent B-N bonds.[2] In another approach, progress towards the development and characterisation of spin-crossover cages[3] with increased complexity will be discussed. References [1] A. J. McConnell, C. S. Wood, P. P. Neelakandan, J. R. Nitschke, Chem. Rev. 2015, 115, 7729-7793. [2] E. N. Keyzer, A. Sava, T. K. Ronson, J. R. Nitschke, A. J. McConnell, Chem. Eur. J. 2018, 24, 12000-12005. [3] A. J. McConnell, Supramol. Chem. 2018, 30, 858-868.

Chemical exchange saturation transfer (CEST) imaging is a relatively new MRI technology allowing the detection of low concentration endogenous cellular proteins and metabolites indirectly through water. CEST MRI is still under development and one major impediment for more widespread application is limited specificity due to spectral overlap of CEST signal from other metabolites and proteins. In this presentation, I will demonstrate several novel CEST spectral editing techniques developed by our group to extract information from CEST images, such as one variable delay multi pulse (VDMP) CEST that acts an exchange rate filter to separate CEST effects from the confounding factors, one ultra-short echo (UTE)-CEST method that can monitor in vivo protein aggregation process and one polynomial and Lorentzian line-shape fitting (PLOF) CEST that can detect creatine and phosphocreatine in tissue with high specialty. Their applications on the stroke and Alzheimer’s disease models will be covered. At last, I will explore one artificial neural network approach to overcome the challenges of implementing the CEST technique on 3T clinical MRI scanners.

The phenomenon of charge regulation was introduced by Ninham and Parsegian almost 50 years ago and was successfully applied in many studies to charged surfaces in contact with an electrolyte. We revisit the charge-regulation mechanism within the Poisson-Boltzmann theory, and apply it to mobile macro-ions in a bathing salt solution. Our findings are, in particular, relevant for solutions of proteins, whose exposed amino acids can undergo charge dissociation/association processes to/from the bathing solution, and can be considered as solution of charged regulated macro-ions

Understanding the function of biomolecules on a molecular level requires knowledge about their structure and conformational changes during function. Site directed spin labeling (SDSL) in combination with pulsed dipolar EPR spectroscopy (PDS) enables to gather such information on the nanometer length scale. In the talk, it will be shown that this approach enables the localization of metal ions within the fold of biomolecules, also of those metal ions with large zero-field splitting, where the high-field approximation breaks down. It will also be shown that this cannot only be done in vitro but also within cells. Last but not least, an example will be given where a conformational change of a protein is not only followed on the length- but also on the microsecond time resolution using PDS/SDSL.

Bambus[n]urils (BU[n]) are macrocyclic molecules discovered by our group and first published in 2010.1,2 They consist of n glycoluril units connected by n methylene bridges. Only four- (n = 4) and six- (n = 6) membered homologues of BU[n] have been isolated so far. Most attention is paid to BU[6] (Figure 1) as this macrocycle is one of the most potent anion receptors for many inorganic anions in water and organic solvents. In this lecture, some important aspects of bambusuril chemistry will be highlighted. The synthesis of BU[6]s will be discussed with emphasis on a template effect, the installation of various substituents on the bambusuril framework, and removal of a templating anion from the BU[6] cavity. Driving forces responsible for the outstanding ability of BU[6] to bind anions in water will be explained and some recent examples of BU[6] applications including anion sensing and anion transport will be given. Finally, approaches leading to chiral bambusurils will be discussed and the first examples of such macrocycles will be presented as well as their use in enantiomer recognition. Figure 1. Structure of bambus[6]urils. References [1] J. Svec, M. Necas and V. Sindelar, Angew. Chem. Int. Ed., 2010, 49, 2378. [2] T. Lizal and V. Sindelar, Isr. J. Chem. 2018, 58, 326.

Hsp90 plays a central role in cell homeostasis by assisting folding and maturation of many client proteins. In order to perform this chaperoning activity Hsp90 hydrolyzes ATP, which requires Mg(II) as cofactor and the hydrolysis is coupled to large global conformational changes. Hsp90 is homo-dimeric with each monomer consisting of three consecutive domains (CTD, MD, NTD). The ATPase site is found in each of the two NTDs, while the CTDs constitute the dimerization site. X-ray crystallography and FRET have provided insights on the conformational cycle of Hsp90 which involves transition from a nucleotide-free ‘open’ to a nucleotide-bound ‘closed’ conformation by dimerization of the NTDs. However, there are still open questions on whether the chaperone shifts global conformation as a consequence of hydrolysis. Here, we investigate the ATPase site and the concomitant conformational changes at various nucleotide-bound states (pre-hydrolysis, intermediate high energy and post- hydrolysis states) in yeast Hsp90 using EPR techniques. To do so, we substituted the Mg(II) cofactor with paramagnetic Mn(II) and performed hyperfine and pulsed dipolar EPR experiments, to probe short and long range interactions, respectively. Specifically, we tracked ATP hydrolysis by exploring the Mn(II) coordination by the nucleotide phosphates using 31P electron nuclear double resonance (ENDOR) spectroscopy. The interaction of the Mn(II) with protein residues in the different hydrolysis states was investigated by 14/15N ELDOR-detected nuclear magnetic resonance (EDNMR). Last, we measured the distance between the two Mn(II) cofactors in each of the monomers using double electron–electron resonance (DEER/PELDOR) spectroscopy. Here, we measured a well-defined Mn(II)-Mn(II) distance of 4.3 nm in the pre-hydrolysis state, which changes both in width and mean distance in the post-hydrolysis state providing experimental evidence to the existence of two different ‘closed’ conformations for the ATP and ADP bound states. Within our approach one can probe both local and global interactions from a single sample via exploitation of intrinsic sites (here Mg(II)->Mn(II)) that can potentially yield new structural insights previously challenging to observe with FRET and EPR using site-specific spin labeling.

4H-SiC epitaxial layers were irradiated using various radioactive sources and particle accelerators. The electronic properties of induced defects were characterized by means of deep-level transient spectroscopy (DLTS) and Laplace DLTS. This presentation is a review of various observations due to processing various particles used in irradiation of 4H-SiC. From the results it was evident that the same defects were induced by various radiation sources. Irradiation induced the acceptor level of the Z1 center and the donor level of the Z2 center. The concentration of the native defects, which originate from impurities encountered in the growth process increased. DLTS spectra observed after irradiation were exhibited sitting on skewed baselines which in some instances inhibited accurate Laplace-DLTS resolution.

4H-SiC epitaxial layers were irradiated using various radioactive sources and particle accelerators. The electronic properties of induced defects were characterized by means of deep-level transient spectroscopy (DLTS) and Laplace DLTS. This presentation is a review of various observations due to processing various particles used in irradiation of 4H-SiC. From the results it was evident that the same defects were induced by various radiation sources. Irradiation induced the acceptor level of the Z1 center and the donor level of the Z2 center. The concentration of the native defects, which originate from impurities encountered in the growth process increased. DLTS spectra observed after irradiation were exhibited sitting on skewed baselines which in some instances inhibited accurate Laplace-DLTS resolution.

In this talk, I will introduce the Nature Communications journal, the editorial office in Shanghai, the editorial process and insiders’ view on the Nature Communications. Bo joined Nature Communications in March 2017. Following his undergraduate studies in Zhejiang University, China, he obtained his PhD in Physics at National University of Singapore. He then carried out his postdoctoral research at Graphene Research Center in Singapore and University of Washington. He currently handles manuscripts on solar cells and halide perovskite photophysics. Bo is based in the Shanghai office.

Nitrogen Vacancy (NV) centers in diamond have emerged over the past few years as well-controlled quantum systems, with promising applications ranging from quantum information science to magnetic sensing. In this talk, I will first introduce the NV center system and the experimental methods used for measuring them and controlling their quantum spin dynamics. I will mention the application of magnetic sensing using NVs through the realization of a magnetic microscope [1]. I will then describe our work on nuclear hyperpolarization, potentially relevant for enhanced MRI contrast, and research into open quantum systems and quantum thermodynamics [2]. Finally, I will present related control sequences, which can be used to perform optimized quantum noise spectroscopy, allowing for precise characterization of the environment surrounding a quantum sensor [3]. 1. E. FARCHI ET. AL., SPIN 7, 1740015 (2017). 2. HOVAV, Y., NAYDENOV, B., JELEZKO, F. AND BAR-GILL, N., PHYS. REV. LETT. 120, 6, 060405 (2018) 3. Y. ROMACH ET. AL., PHYS. REV. APPLIED 11, 014064 (2019).

Halide (hybrid) perovskites (HaP) have emerged as a new class of semiconductors that truly encompass all the desired physical properties for building optoelectronic and quantum devices such as large tunable band-gaps, large absorption coefficients, long diffusion lengths, low effective mass, good mobility and long radiative lifetimes. In addition, HaPs are solution processed or low-temperature vapor grown semiconductors and are made from earth abundant materials thus making them technologically relevant in terms of cost/performance. As a result, proof-of-concept high efficiency optoelectronic devices such as photovoltaics and LEDs have been fabricated. In fact, photovoltaic efficiencies have sky rocketed to 23% merely in the past five years and are nearly on-par with mono-crystalline Si based solar cells. Such unprecedented progress has attracted tremendous interest among researchers to investigate the structure-function relationship and understand as to what makes Halide hybrid perovskites special? In my talk, I will attempt to answer some of the key questions and in doing so share the results from our work on HaPs over the past four years in understanding structure induced properties of HaPs. I will also highlight fundamental bottlenecks that exist going forward which present opportunities to create platforms to understand the interplay between light, fields and structure on the properties of perovskite-based materials.

3D halide perovskites have emerged as a new class of semiconductors, but some basic optoelectronic properties of 3D bulk halide perovskites are still shrouded in mystery. The talk will start from a simplified representation of the halide perovskite lattice allowing to progressively account for various advanced topics.

Mixing semi-dilute solutions of oppositely charged polyelectrolytes generally yields compositions spanning complexes (solid) to coacervates (elastic liquid) to dissolved solutions with increasing salt concentration. In this work we show how to form a strong network of oppositely charged polyelectrolytes by using an interplay of hydrogen, hydrophobic, and electrostatic interactions.

Recent developments in pulse sequences and NMR hardware have opened up many "exotic" nuclides in the periodic table to experimentation by solid-state NMR. Many of these nuclides are classified as unreceptive, and have been avoided by NMR spectroscopists and chemists in general, due to factors such as low Larmor frequencies, low natural abundances, inconveniently short or long relaxation times, etc. In addition, there are numerous systems in which these nuclides have extremely broad NMR patterns resulting from large anisotropic chemical shielding or quadrupolar interactions. Such nuclei have long been classified as "invisible", since their NMR spectra cannot be observed using standard NMR pulse sequences. In this lecture, I will show that there are several robust strategies one can apply to acquire high quality solid-state NMR spectra of a variety of nuclei, including 10B, 14N, 27Al, 35/37Cl, 47/49Ti, 59Co, 63/65Cu, 69/71Ga, 91Zr, 93Nb, 139La, 195Pt, and 209Bi. Ultra-wideline NMR spectra, when coupled with X-ray crystallography and ab initio methods, provide powerful probes of molecular structure in inorganic, organic and organometallic materials. New advances in dynamic nuclear polarization (DNP) NMR for the acquisition of ultra-wideline NMR spectra will also be discussed

A few nanometer thin interface which is formed between the metal and the organic structure controls bonding strength, stability and charge transfer between these two quite different types of materials. To understand and optimize formation of that interface at the nanoscale we used Self-Assembled Monolayers (SAMs) which are considered a model system for the analysis of the interaction of organic molecules with the metal substrate. In this presentation we will focus on application of a new experimental approach based on ion beam-induced desorption which we used to address this problem demonstrating for the first time the effect of oscillations in stability of consecutive chemical bonds at the molecule-metal interface. As a next step we will analyze the consequence of this effect for the thermal stability of a model SAM systems and, finally, we will discuss how this effect can contribute to the charge transport at the molecule-metal interface

What happens to electrons in a metal when they are illuminated? This fundamental problem is a driving force in shaping modern physics since the discovery of the photo-electric effect. In recent years, this problem resurfaced from a new angle, owing to developments in the field of nano-plasmonics, where metallic nanostructures give rise to resonantly enhanced local electromagnetic fields (surface plasmons). Presumably, these plasmons can transfer their energy to the electrons in the metal very efficiently, creating “hot electrons”, i.e. energetic electrons out of equilibrium. Such energetic electrons have been demonstrated to be useful in a variety of ways, most recently in catalysis of chemical reactions. Or have they? In this talk we argue that what appears to be hot-electron-mediated photo-catalysis is really a simple heating effect. We present a theory for plasmonic hot-electron generation, which takes into account non-equilibrium as well as thermal effects. Specifically, we consider the effect of both photons and phonons on the electron distribution function, and calculate self-consistently the full electron distribution and the increase in electron and lattice temperatures above ambient conditions (as observed experimentally), thus going well beyond the limit of existing theories. Calculating the efficiency of hot-electron generation, we find that it is extremely small, and most power goes into heating. We use this theory to re-interpret data from central experiments claiming hot-electron generation, and find that the data fits remarkably a simple theory of heating. Finally, we suggest control experiments to further test our conclusions, and discuss the prospect of using the hot electrons for photocatalysis.

Accurate prediction of electronic properties of open-shell transition metal complexes is essential for materials design and catalysis. Nevertheless, the properties that make these materials and molecules so compelling also make them extremely challenging to study accurately with any computational model. Although density functional theory (DFT) remains the method of choice for its balance of speed and accuracy in computational screening, semi-local approximations in density functional theory (DFT), such as the generalized gradient approximation (GGA), suffer from many electron self-interaction errors that causes them to predict erroneous spin states and geometries, barrier heights and dissociation energies, and orbital energies, to name a few. I will outline our recent efforts to both understand and correct these errors with a focus on predictive modeling of transition metal chemistry : i) We describe how common approximations to recover the derivative discontinuity (i.e., DFT+U and global or range separated hybrids) affect the density properties of transition metal complexes and correlated solids with respect to exact references, ii) We demonstrate recovery of the flat-plane condition that is a union of the requirement of piecewise linearity with electron removal or addition as well as unchanged energy when changing the spin of an electron in isoenergetic orbitals. We accomplish this at no computational cost over semi-local DFT by building from scratch our judiciously-modified DFT (jmDFT) functionals designed to oppose errors inherent in semi-local functionals. We show the connection to but divergence of these functional forms from hybrid expressions and standard DFT+U explain why both common approximations increase static correlation errors. We also present fundamental expressions for determining these parameters, mitigating any empiricism in the method. iii) Finally, time permitting, I will describe our efforts to overcome DFT inaccuracies through the development of data-driven structure-method relationships, including in artificial neural networks that can predict sensitivity of spin-state ordering in transition metal complexes to changes in the exchange-correlation functional.

Peptides in -sheet conformations have been developed in our lab in a bottom up fashion towards various biomedical applications. Hydrogels of -sheet peptides will be briefly introduced and the talk will then focus on peptide coatings for induced osseointegration of titanium implants and peptides enhanced nanoparticles for intracellularly targeted drug delivery.

Parallel transmission has been the most promising approach to counteract the radiofrequency (RF) field inhomogeneity problem in MRI at ultra-high field. Despite tremendous progress made by the community for more than a decade, the technology yet has failed to be embraced in routine practice because of a more complex safety management and a cumbersome calibration procedure for each subject in the scanner. After thorough tests and validations to address the former point, universal pulses were proposed a couple of years ago to circumvent the workflow problem in head imaging at 7T. For a given RF coil, they consist of designing, offline, pulse solutions to mitigate the RF field inhomogeneity problem while being robust to intersubject variability, all within explicit hardware and safety constraints. This talk will present the latest sequence and pulse developments incorporating these solutions, now covering 3D (GRE, MPRAGE, TSE, MP-FLAIR, DIR, 3D-EPI) and 2D (GRE, MB-EPI) sequences with first routine results for fMRI (resting-state HCP-style, localizer paradigm) and ongoing clinical studies (Multiple Sclerosis), thereby making parallel transmission one step closer to clinical routine and at zero cost for the user. Perhaps interestingly, to reach the desired versatility and simplicity, some solutions were inspired from solid-state NMR methods. To date the proposed universal pulses cumulate tests on around 50 volunteers and across 4 sites. They have never failed to return brain images virtually free of B1+ artefacts at 7T.

Nanomechanical measurements allow us to determine mechanical characteristics of nano- and microobjects, which is required for further calculations of the mechanical parameters of the structures based on them. At the same time, in-situ measurements are carried out in the SEM and TEM chambers. Thus, it is possible to acquire graphic information that can supplement the indentation data. In this work, indentation of titania microspheres with different phase composition was tested by MEMS-based Hysitron PI-95 at Zeiss Libra 200MC TEM. Evaluation of the mechanical properties of microspheres in the elastic region was made according to the Hertz model. It turned out that annealing of the amorphous titania leads to an increase in the Young modulus, whereas the hydrothermal treatment reduces it from 27 to 4 Gpa. The differences in the destruction process was demonstrated for these kinds of particles. It has been shown, that hydrothermal treatment of titania microspheres leads to the formation of a reticular internal structure, whereas annealing results in sintering of the internal structure of microspheres. In the process of indentation, corresponding videos were also recorded, including the probe approach, indentation, and destruction of the microspheres. In order to process the videos we coded the program based on free Python packages. Using the Digital Image Correlation (DIC) algorithm, relative probe displacements were measured during indentation (Fig. 1a). The results obtained allowed us to clarify the calibration of the movement of the indenter in free sample tests, as well as to determine the drift function in real measurements. These results are important for long-term measurements, in particular creep tests. Based on graphical data we were able to determine the evolution of the shape of indented microspheres. During the video processing, areas of individual objects were determined, sizes of contact areas were calculated, and changes in linear dimensions of the deformed objects were determined (Fig. 1b). Therefore, a large amount of quantitative data was obtained from electron microscopy images. Fig.1 Illustration of probe displacement determination (a) and the shape evolution analysis

Electrostriction is a second order electro-mechanical coupling that exists in all dielectrics. Classical electrostriction describes anharmonic perturbation of the chemical bonds in the lattice, which gives rise to changes in the average position of atoms. It was found that the mechanism of electrostriction in gadolinium doped ceria (CGO) is fundamentally different from that of classical electrostriction, in which high electrostriction goes together with a large dielectric constant. The mechanism of electrostriction in CGO is not known yet. However, the current hypothesis attributes it to rearrangement of local distortions in the fluorite lattice. This PhD thesis presents investigation of non-classical electrostriction effect in self-supported films of gadolinium doped ceria: dependence of the electrostriction strain coefficient on frequency and magnitude of the electric field and mechanical fatigue in thin films. Using self-supported Al/Ti/CGO/Ti/Al structure, I also identified electro-chemo-mechanical effect, which was previously considered unfeasible actuation mechanism at room temperature. The processes presented in this work provide a technological basis for integrating CGO as an active material in electro-active ceramic MEMS (microelectromechanical system)-actuation devices.

Despite the importance of tissue microstructure in health and disease, its noninvasive characterization remains a formidable challenge. Signal representations (diffusion/kurtosis tensors) are unspecific while tissue modelling using ideal geometries representing different cellular components have failed when scrutinized vis-à-vis histology: axon diameter, for example, is overestimated by factors of >6. Biophysical models characterizing signal behavior in specific diffusion-weighting regimes (power law scaling in “q” or “t”) have been more recently proposed as more reliable means for characterizing tissues. In recent years, the most prevalent biophysical model for diffusion in tissues was termed the “Standard Model”, consisting of a sum of gaussian components (nearly always two), one of which with zero diffusivity (stick). In the lecture, we will present validity regimes for the standard model and provide evidence for its limits. We will then propose a few novel means for characterizing