Achiral bent-core liquid crystals with azo and azoxy linkages: Structural and nonlinear optical properties and photoisomerization

We present a structural study of the mesophases of three achiral bent-core compounds with azo and azoxy bonds. The study is based on textures observation and small-angle X-ray diffraction. It is found that the materials exhibit columnar and tilted smectic mesophases. Optical second-harmonic generation measurements are performed on aligned samples of one of the compounds, and the whole second-order susceptibility tensor is determined. Finally, some simple aspects of the photoisomerization of the materials are examined.