Aromatic azomonoethers as new organic materials for nonlinear optics

The present paper reports the synthesis and characterization of eleven new aromatic azomonoethers, having general formula [GRAPHICS] where R is a nematogenic group (Cl, CN, CF3) or a highly polarizable group NO2. The liquid crystalline nature of these compounds was studied by calori metric measurements and optical texture observations. The C6H4CN substituen t enhanced nematic thermal stability and repressed smectic properties while terminal CF3 group favored smectic A mesophase formation. The azomonoether s obtained using 1-chloro4-(chloro-methyl)benzene and the corresponding azo phenols should possess nonlinear optical properties.