Thioether-Linked Liquid Crystal Trimers: Odd-Even Effects of Spacers and the Influence of Thioether Bonds on Phase Behavior.

ABSTRACT: We report the synthesis, phase-transition behavior, and mesophase structures of the first homologous series of thioether-linked liquid crystal (LC) trimers, 4,4'-bis[ω-(4-cyanobiphenyl-4'-ylthio)alkoxy]biphenyls (CBSnOBOnSCB with a wide range of spacer carbon numbers, n = 3-11). All CBSnOBOnSCB homologs exhibited LC phases. Interestingly, even-n and odd-n homologs showed monotropic layered smectic A (SmA) and pseudo-layered twist-bend nematic (NTB) phases, respectively, below a nematic (N) phase. This alternate formation, which depends on spacer chain parity, is attributed to different average molecular shapes, which are associated with the relative orientations of the biphenyl moieties: linear and bent shapes for even-n and odd-n homologs, respectively. In addition, X-ray diffraction anal

SUBMITTER: Arakawa Y 

PROVIDER: S-EPMC8911043 | biostudies-literature | 2022 Feb

REPOSITORIES: biostudies-literature