Syntheses and Thermal Properties of New Liquid Crystals Bearing a Crown Ether Ring: Cation Binding in the Nematic Phase

A series of crown ether derivatives containing a biphenyl or cholesteryl moiety have been synthesized for the first time. The structural effects of these compounds on the formation of liquid-crystalline phases are discussed. We have found that benzo crown ether derivatives bearing a p-cyano- or p-(octyloxy)biphenyl moiety linked by an ester or ethyne group display a nematic liquid-crystalline phase, and 4'-((cholesteryloxy)carbonyl)benzo crown ethers exhibit a cholesteric phase