Cubic-cubic phase transition of thermotropic hydrogen-bonded cubic mesogens 1,2-bis(4'-n-alkoxybenzoyl)hydrazines (BABH-n) as studied by infrared spectroscopy

Abstract

Thermotropic hydrogen-bonded cubic mesogens 1,2-bis(4'-n-alkoxybenzoyl)hydrazines (BABH-n, where n is the number of carbon atoms in the alkyl chain) supramolecularly organize into, two types of bicontinuous cubic (Cub) phases (Ia3d and Im3m phases). Interestingly, BABH-13 exhibits an Ia3d to Im3m transition whereas the reverse direction of the transition is observed for BABH-16, on heating. In this study, to elucidate the changes in aggregate structure at the Cub-Cub phase transitions, infrared spectra were monitored with time. The obtained results are discussed with those from time-resolved X-ray diffraction studies for the corresponding processes.