NEW LIQUID-CRYSTALLINE COMPOUNDS BASED ON 1,4-DIARYLBUTA-1,3-DIENES

The first group of fully characterised mesogenic E,E)-1,4-diarylbuta-1,3-dienes, substituted in the para-position of one aryl ring by an alkoxy-group and in the para-position of the other aryl group by a cyano- or halogeno-group has been prepared by a Wadsworth-Emmons procedure; their physical properties of high birefringence and low viscosity in combination make them particularly suitable for use in liquid crystal display devices when mixed with known liquid crystalline materials.