Nematic Liquid Crystal Compounds with Five-Ring Framework

Abstract

A series of novel liquid crystal compounds with five-ring framework having a –CF2O- linkage group (1a–1e) has been synthesized and their physical properties were measured. These compounds are characterized to have higher nematic-isotropic liquid transition temperatures and broader mesophase temperature range. As for the anisotropic properties, this series is categorized as compounds having large Δϵ and Δn. Although these compounds possess five rings in their structures, they exhibit high miscibility caused by the rotately non-symmetric structures including the lateral fluorine substituted phenylene rings. One of the novel compounds exhibits SmF phase and shows the second-order phase transition of SmA to SmC. The compounds are effective to improve the response property of the mixtures due to their high elastic constants. These five-ring compounds possess diversified properties and of high potential materials for improving the LCD performances.