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Template-directed synthesis can be used to create π-conjugated porphyrin nanorings that are as big as proteins, with diameters ranging from 2 nm to more than 20 nm. These nanorings mimic the ultra-fast energy migration of photosynthetic light-harvesting chlorophyll arrays. They are highly redox active and they display global aromaticity in some oxidation states. For example, the 12-porphyrin nanoring is globally aromatic in its 6+ oxidation state with a Hückel circuit of 4n + 2 = 162 π electrons (diameter 5 nm). This is the largest aromatic circuit yet reported. The aromatic and antiaromatic ring currents confirm that there is long-range charge delocalization. Recent work on these systems will be presented.

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.

The assembly of neural circuits critical for visual system function includes the differentiation of select subtypes of amacrine cells (ACs) and retinal ganglion cells (RGCs), the elaboration of precise connections within the retina among ACs and RGCs, and targeting of RGC axons to their appropriate retino-recipient regions within the CNS. I will consider these events in the context of the mammalian accessory optic system (AOS), which is tuned to detect slow directional motion in order to stabilize images on the retina. This work implicates mutations in certain human genes that encode orthologues of proteins critical for assembling murine AOS circuits in phylogenetically conserved aspects of visual system function.

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