2,7-di(hydroxylated) hexaalkoxy triphenylenes as building blocks for supramolecular and macromolecular liquid crystals and organogels

NAHIR VADRA; CRISTIAN HUCK IRIART; GIOVANETTI, LISANDRO J.; DI CHENNA, PABLO H.; CUKIERNIK, FABIO D.

lisboa

Conferencia; 28th international Liquid Crystal Conference; 2022

International Liquid Crystal Society

Three triphenylene (TP) compounds bearing four ancillary hexyloxy chains and two variable-length alkoxy chains terminally functionalized with hydroxyl groups -denoted 2,7-THTP-DiCnOH- have been synthesized and characterized; their self-assembling capabilities have been studied. They differ in the length of the spacer between the OH functional groups and the TP core (n= 4, 6 and 10). All of them exhibited thermotropic mesomorphism (N and ColR); the detailed nature of the mesophases was found to depend on the position of the terminal functional groups relative to the crown formed by the ancillary chains. Moreover, the three compounds were able to act as supramolecular gelators in a variety of alcohols; remarkably stable gels have been detected for 2,7-THTP-DiC6OH in methanol.Their organogelating ability has been rationalized in terms of selected physicochemical parameters; among them, the dielectric constant allowed to establish an extremely precise predictive ?solvent gelation window? for each compound. As a proof of principle, we present the water sensing performance as a very simple method for the assessment of water content in alcohols samples based on the influence that the water content exerts on gel´s thermostability. Additionally, the n = 4 and 6 derivatives have successfully been incorporated into main-chain polyesters, by copolymerization with commercial α,ω-dicarboxylic acids. They exhibited room temperature N mesophases with spontaneous homeotropic alignment on glass and NaCl substrates.