Synthesis and Mesomorphic Properties of Azo Compounds Derived from Phenyl-and Thienyl-1,3,4-Thiadiazole

Abstract

The synthesis and mesomorphic behaviour of new series of liquid crystals containing 1,3,4- thiadiazole and thiophene rings with azo central bond are reported (series 5a and 5b). All compounds of series 5a exhibit enantiotropic nematic mesophase and the higher homologues (n = 9 - 10) also show a monotropic smectic C phase. Series 5b show dimorphism S C - N (for n = 5 - 7 the S C is monotropic). These series are compared with the Schiff’s bases analogues, the imine bond gives rise to similar liquid crystals phase but larger mesomorphic range.