Diphenyl-1,3,4-oxadiazoles: synthesis and influence of side chain semifluorination and lateral ring fluorination on liquid crystalline properties
作者:Farid S. Fouad、Melati Khairuddean、Robert J. Twieg
DOI:10.1080/15421406.2021.1980711
日期:2022.1.2
Abstract We present the synthesis and liquidcrystalline properties of four sets of diphenyl-1,3,4-oxadiazole based compounds (Sets 1–4). The influence of side chain and lateral fluorinations is discussed. In this study, side chain fluorination (Sets 2 and 3) induces liquidcrystalline properties, while lateral fluorination (Set 4) has not induced mesogenic properties. Compounds with either one or
Liquid Crystals Derived from Semifluorinated Alkoxybenzoyl Hydrazines
作者:Melati Khairuddean、Robert J. Twieg
DOI:10.1080/15421400902841478
日期:2009.5.18
A variety of liquid crystals with semifluorinated tails including 4-alkoxybenzoic acids (1d-h), 4-alkoxybenzoyl hydrazines (2d-h), and N,N'-bis(4-alkoxybenzoyl) hydrazines (3d-m) have been synthesized, and their properties are compared with their perhydrogenated analogs. Semifluorination in compounds 1d-h suppressed nematic phases, and semifluorinated compounds 2d-h exhibit mesogenic behavior where none is found in their perhydrogenated counterparts. Compounds 3a-c with perhydrogenated chains display Cub and SmC phases. Introduction of one semifluorinated chain, 3d-h suppresses the Cub phase but induces a SmA phase, with lower melting but higher clearing temperatures compared to compounds with two semifluorinated chains, 3i-m. The mesogenic properties of some selected binary mixtures of these compounds 3a-d and some lateral fluoro substituted N,N'-bis (4-alkoxybenzoyl) hydrazines 7-9 are also discussed.
Synthesis and mesomorphic properties of 5-(p-n-alkoxy)phenyl-2-(p-n-octyloxy)benzylideneamino-1,3,4-thiadiazoles