Novel liquid crystal structures in cyano bi-cyclohexanes

The structures of liquid crystal phases of three members of the series have been determined. All have nematic phases with extremely weak pseudo-layer density fluctuations and the two lowest members have bilayer smectic B type structures in which tails and cyano end groups are interdigitated. There also exist in the SB structures pronounced local modulations probably of a polar antiphase nature associated with a tendency to end-to-end ordering. In contrast cyano compounds of the type where is either cyclohexane or bi-cyclooctane have a local bilayer packing similar to that of the analogous biphenyls.