Syntheses and Thermal Properties of New Liquid Crystalline Materials Involving Tropolone

Summary To examine the effect of a tropolone ring system on mesomorphic behavior, the following 2- and 3-ring compounds have been prepared. The 2-ring compounds are non-mesogenic whereas the 3-ring compounds exhibit nematic phases of high stability when R = alkyl or alkoxy, X˭—CH˭N—or—N˭N—, and Y = OH or OCH3, and an additional smectic phase when R = alkoxy. The nematic phase tends to align homeotropically when placed between two glass plates.