SELF-ASSEMBLY OF GUANOSINE: MOTIFS, LIQUID CRYSTALS AND CD CHARATERISATIION

Mimicking the hierarchical self-assembly observed in nature has long been recognised as a powerful strategy for bottom-up fabrication of sophisticated functional nanoarchitectures. This lecture describes some recent advances in the form and function provided by self-assembly of guanine (G) based systems. The presentation gives a brief historical context of G self-assembly in water and then describes studies on lipophilic guanosine analogs in organic solvents. Depending on the experimental conditions, lipophilic guanosines can undergo different self-assembly pathways. Notably, the presence of monovalent and divalent cations can template the formation of G-quadruplex-based octamers or columnar aggregates, depending on the concentration of the ion and nucleobase. These chiral, columnar structures may self-correlate to give a liquid crystalline order. In the absence of metal templates, guanosines (without a C-8 substituent) self-assemble, both in solution and in the solid state, into ribbon-like architectures possibly leading to lyotropic mesophases. The lecture also focuses on the use of CD for investigating guanosine self-assembly and on a few examples of how G analogs have been used as building blocks for functional applications in supramolecular chemistry, material science and nanotechnology.