Pressure Dependence of the Nematic State Tempera- ture of a Compensated Cholesteric Liquid Crystal Optical Rotatory Power Measurements with a Choles- teryl chloride and Cholesteryl nonanoate Mixture

At a certain temperature Tn (nematic temperature) a mixture of two cholesteric components which separately form helices of opposite senses behaves like a nematic. An inversion of the helical structure occurs when passing Tn, from a right-handed to a left-handed structure or vice versa. In the temperature-pressure space such compensated mixtures therefore will exhibit an inversion line which — on the basis of optical rotatory power measurements under high pressure — is presented for the first time.