Liquid crystalline properties and photochromism of N-[4-(4-n-alkoxybenzoyloxy)-2-hydroxybenzylidene]-methoxy and -ethoxy anilines

New homologous series of N-4-(4-n-alkoxybenzoyloxy)-2-hydroxybenzylidene]-methoxy and -ethoxyanilines were synthesized. The phase transitions of these homologues were determined using differential scanning calorimetry and an polarizing microscopy: para-substituted homologues exhibit a nematic phase, while ortho-substituted members do show no mesomorphic phase. In addition, some members of these homologous series exhibit a photochromic property in the solid state.