Determination of the Layer Structure of Twin-type Liquid Crystals with the Inversely Oriented Carbonyl Groups

Abstract

Troponoid twins 1 and 2 which have long alkyl chains show a smectic C phase. By X-ray diffraction study, the layer spacing of I is shorter than the molecular length of I calculated by MM2 method. We plotted the layer spacing vs the terminal alkyl chain length (m) to estimate that the layer spacing of the core part is 12.6 Å. From these results, we proposed the layer structures of twin dimers 1.