Synthesis and Chromatographic Properties of Liquid Crystalline Polysiloxanes Containing Steroid Substituents

A series of alkenyl-substituted cholesterol and related steroids have been prepared. These liquid-crystalline compounds were hydrosilylated onto polyhydromethylsiloxane. The polymers have a broad range of liquid crystallinity even if the starting alkenes had a narrow range. Those polymers containing the benzoate ester linking group were not suitable for stationary phases in high temperature capillary gas chromatography because the phases were not stable at temperatures above 250°C-27O°C. A capillary column coated with a polymer containing a phenyl group directly attached to the steroid proved to be effective in separating certain PAH isomers.