Self-Assembly Basics

Self-assembly mechanisms are not well understood. This is because noncovalent organization is a complex process involving many molecules, solvent, and multiple interaction modes. Crystallization is an ultimate self-assembly leading to ordered systems (crystals) with advantageous functions. Thus, crystallization of organic molecules in solution is of primary importance in materials science, the pharmaceutical industry, and organic synthesis. However, controlling organic crystallization in solution has been a long-standing challenge, and the mechanistic insight into crystal evolution, especially into its early stages remains elusive. There is emerging evidence that complex crystallization mechanisms, involving intermediate noncrystalline aggregates, often operate in inorganic, organic, and protein crystallization in solution. Thus, a two-step nucleation mechanism and the existence of pre-nucleation aggregates (clusters) have been proposed to explain the discrepancies between classical nucleation theory (CNT) and experiments. In fact, a 100-years old CNT does not explain the majority of the crystallization processes, and the area of crystallization mechanisms is wide open!  In our lab, we showed that the pre-nucleation phases play a key role in organic crystallization, and demonstrate that manipulating their structure and dynamics can regulate crystallization aptitudes, ultimately enabling control over organic (nano)crystallization. Importantly, we directly image (!) the order evolution process in organic and protein crystallizations using cryogenic electron microscopy (cryo-EM), which is our spécialité. We also study thermodynamics and kinetics of self-assembly processes in our quest to understand how hydrophobic interactions bring about robustness and unique assembly modes.

 

Shahar, Chen; Dutta, Sounak; Weissman, Haim; Shimon, Linda J W; Ott, Holger; Rybtchinski, Boris (2016). Precrystalline Aggregates Enable Control over Organic Crystallization in Solution.  Angewandte Chemie - International Edition. 55:179-82.

 

Kossoy, E; Weissman, H; Rybtchinski, B (2015). Bending Nanofibers into Nanospirals: Coordination Chemistry as a Tool for Shaping Hydrophobic Assemblies.  Chemistry-A European Journal. 21:166-176.

 

Bar On, A; Tidhar, Y; Pinkas, I; Weissman, H; Rybtchinski, B (2014). Supramolecular Nanofibers Self-Assembled from Foldamers: Structure Control through Preassembly.  Israel Journal Of Chemistry. 54:748-758.

 

Baram, J; Weissman, H; Rybtchinski, B (2014). Supramolecular Polymer Transformation: A Kinetic Study.  Journal Of Physical Chemistry B. 118:12068-12073.

 

Tidhar, Y; Weissman, H; Tworowski, D; Rybtchinski, B (2014). Mechanism of Crystalline Self-Assembly in Aqueous Medium: A Combined Cryo-TEM/Kinetic Study.  Chemistry-A European Journal. 20:10332-10342.

 

Tidhar, Y; Weissman, H; Wolf, SG; Gulino, A; Rybtchinski, B (2011). Pathway-Dependent Self-Assembly of Perylene Diimide/Peptide Conjugates in Aqueous Medium.  Chemistry-A European Journal. 17:6068-6075

 

Krieg, E; Weissman, H; Shimoni, E; On, AB; Rybtchinski, B (2014). Understanding the Effect of Fluorocarbons in Aqueous Supramolecular Polymerization: Ultrastrong Noncovalent Binding and Cooperativity.  Journal Of The American Chemical Society. 136:9443-9452.