作者:Karina Geese、Marko Prehm、Carsten Tschierske
DOI:10.1039/c0jm01919d
日期:——
Bent-core mesogens with thiophene and 2,2′-bithiophene units at the periphery of the aromatic core were synthesized and investigated by polarizing microscopy, XRD and electrooptical methods. Resorcinol, 2,7-naphthalenediol and 3,4′-biphenyldiol were used as bent units, phenyl thiophene-2-carboxylates form the rod-like wings and n-alkyl chains as well as olefin- and silylated-terminated alkyl chains were attached as flexible end-groups. A broad variety of different mesophase structures, incorporating ferroelectric and antiferroelectric switching smectic as well as modulated smectic phases, was obtained. Compared with the corresponding benzoates, these thiophene derived compounds form nearly identical LC phase structures, but have significantly reduced transition temperatures, which make them advantageous for applications.
具有噻吩和2,2'-双噻吩单元位于芳香核边缘的弯曲核心介晶被合成并通过偏光显微镜、XRD和电光方法进行了研究。间苯二酚、萘-2,7-二醇和3,4'-联苯二醇被用作弯曲单元,苯基噻吩-2-羧酸酯形成棒状翼,以及作为柔性末端基团的正烷基链、烯烃和硅烷化的烷基链被附加。获得了包含铁电和反铁电开关层状以及调制层状相的多种不同的介相结构。与相应的苯甲酸酯相比,这些来源于噻吩的化合物形成了几乎相同的液晶相结构,但具有显著降低的转变温度,这使得它们在应用上具有优势。