Synthesis of 1,3-Dioxane Derivatives with Large Negative Dielectric Anisotropies

Abstract

Liquid crystalline r-2-t-5-disubstituted c-5-cyano-1,3-dioxanes have been synthesized. The melting temperature of the new substances are increased in comparison to simpler 2,5-disubstituted 1,3-dioxanes, whereas the clearing temperatures are of the same order of magnitude. These compounds exhibit large negative dielectric anisotropies. Some of the 2-cyclohexyl-substituted derivatives have S_c-phases.

Key Words:

• liquid crystals
• negative dielectric anisotropy
• S_c-phases
• 5-cyano-1,3-dioxane derivatives
• synthesis
• selective reduction