Liquid Crystalline Cholestanyl and Cholesteryl Ether Lipids

Abstract

A homologous series of 3ß-alkyl cholestanyl ethers was prepared and their liquid crystalline properties were studied. The compounds with alkyl groups consisting of n = 3 to n = 20 carbon atoms exhibit a cholesteric phase. In addition, the ethers with alkyl groups consisting of n = 9 to n = 18 carbon atoms show a S_A phase. Ordered or tilted smectic phases or blue phases are not observed. The S_A phase shows unusual textures several tenths of a degree below the transition to the cholesteric phase. The results obtained are compared with those of 3ß-alkyl cholesteryl ethers and other homologous series of cholestanyl derivatives such as cholestanyl esters and cholestanyl carbonates.

Key Words:

• liquid crystals
• cholestanyl ethers
• steroidal ether lipids
• smectic A