화학공학소재연구정보센터
Molecular Crystals and Liquid Crystals, Vol.623, No.1, 129-138, 2015
Mesomorphism of Novel Symmetric Dimers with Changing Alkoxy Terminal End Group
A novel homologous series of symmetric dimers has been synthesized. It consists of thirteen (C-1 to C-8, C-10, C-12, C-14, C-16 and C-18) dimer ester derivatives from trans cinnamic acid with pyrocatechol. Mesomorphic property commences from C-7 homologue as smectic. C-1 to C-6 members of the series are nonmesomorphic. C-7 is monotropic smectic and the rest of the homologues from C-8 to C-18 are enantiotropic smectic. The nematic mesophase is totally absent. Textures and transition temperatures of the homologues are determined by an optical polarizing microscope equipped with a heating stage. IR, H-1 NMR spectra, mass spectra, and differential scanning calorimetry of some members is included. The spectroscopic analyses support the molecular structures. Mesomorphic properties of the novel symmetric dimer series are compared with structurally similar series. The novel series is partly nonmesomorphic and predominantly smectogenic with textures of the A or C type, without the exhibition of the nematic phase.