Liquid Crystal Properties of Some Steryl Chlorides

Abstract

The liquid crystalline properties of cholestanyl, cholesteryl, campesteryl, sitosteryl, and stigmasteryl chlorides were studied by measuring their behavior in mixtures with cholesteryl nonanoate. Of the five chlorides only cholesteryl chloride shows an obvious mesophase temperature range and microscopic texture, but all of the chloride–nonanoate mixtures are cholesteric over a wide range of compositions. The decrease in effective pitch observed as the 17β side chain is modified appears to correspond directly to the complexity of the modification. We conclude that all of the chlorides studied are liquid crystalline despite the fact that the ordinary tests for mesomorphism do not give this indication.