A family of low molecular weight organogelators based on mesomorphic dihydrazide derivatives

The mesomorphic dihydrazide derivatives N-(4-alkoxybenzoyl)-N′-(4′-biphenyl carbonyl) hydrazine (Cn-ph) showed stable liquid crystalline properties and strong gelation ability in organic solvents. Both nematic and smectic phases were found in C6-ph, while only smectic A phase in C10-ph, C12-ph and C16-ph. Cn-ph kept a head-to-tail monolayer molecular arrangement in their smectic phases. In gel phase, molecules of Cn-ph self-assembled into an interdigitated layered structure, which is the fundamental of fibrous aggregations as observed by SEM. Intermolecular hydrogen bonding between the dihydrazide groups of Cn-phs was demonstrated to be the major driving force for both gelation of organic solvents and stabilization of the liquid crystalline phase.