High-Temperature Nematic Liquid Crystal for Gas-Liquid Chromatography

Article abstract of DOI:10.1021/ac50064a042

The synthesis of three liquid crystals with the general formula N,N'-bis(p-alkoxyphenylbenzylidene)-α,α'-bi-p-toluidine where the alkoxy group is represented by methoxy (BABT; nematic range of 253-370 deg C), n-butoxy (BBPT; nematic range of 232-331 deg C), and benzyloxy (BBzPT; nematic range 270-346 deg C) is reported.The liquid crystals were synthesized by the condensation of the appropriate 4'-alkoxybiphenyl-4-carboxaldehyde with α,α'-bi-p-toluidine.The aldehydes were prepared by a five-step procedure starting with 4-hydroxybiphenyl.BABT was chromatographically evaluated.BABT operating in the supercooled nematic region at 230 deg deg C provided better separations of methylbenzanthracene isomers than conventional SE-30, Dexsil 300, and Silicon Gum MS2211 columns.