New chiral side chains for ferro- and antiferro-electric liquid crystals derived from the preen-gland wax of the domestic goose
作者:Gerd Heppke、Detlef Lötzsch、Michael Morr、Ludger Ernst
DOI:10.1039/a704503d
日期:——
(2R,4R,6R,8R)-2,4,6,8-Tetramethyldecanoic acid and (2R,4R,6R,8R)-2,4,6,8-tetramethyldecanol, as well as the (2R,4R,6R,8R) and the (2S,4R,6R,8R) diastereomers of 4,6,8-trimethyldecan-2-ol, have been obtained from the preen-gland wax of the domestic goose. Starting from these alkanols and alkanoic acid, novel ferro- and antiferro-electric liquid crystals bearing four methyl branchings in the chiral side chain have been synthesized and their mesomorphic and electro-optical properties have been investigated. The results obtained are compared with the properties of the respective chiral (S)-2-methyldecanoic acid, (S)-decan-2-ol and (S)-2-methyldecanol derivatives. The compounds with four methyl branchings in the chiral side chain are found to exhibit lower melting points, broader SmC* phase ranges, higher values of spontaneous polarization and larger tilt angles in comparison to the respective compound with only one methyl branching.
从家鹅前腺蜡中获得了 (2R,4R,6R,8R)-2,4,6,8-四甲基癸酸和 (2R,4R,6R,8R)-2,4,6,8-四甲基癸醇,以及 4,6,8-三甲基癸-2-醇的 (2R,4R,6R,8R) 和 (2S,4R,6R,8R) 非对映异构体。以这些烷醇和烷酸为起点,合成了手性侧链中含有四个甲基分支的新型铁电和反铁电液晶,并研究了它们的介形和电光特性。研究结果与手性 (S)-2-甲基癸酸、(S)-2-癸醇和 (S)-2-甲基癸醇衍生物的特性进行了比较。与只有一个甲基支链的化合物相比,手性侧链上有四个甲基支链的化合物表现出更低的熔点、更宽的 SmC* 相范围、更高的自发极化值和更大的倾斜角。