FTIR investigations of phase transitions in an asymmetric azomethine liquid crystal

The liquid crystalline (LC) behavior of a literature-reported asymmetric azomethine compound (4-[4-(n-butyloxy)-benzylideneimino]-chlorobenzene, Cl.O4) was investigated by using optical polarized light microscopy, differential scanning calorimetry and medium-wide angle X-ray diffraction. FTIR in attenuated total internal reflection configuration was employed to study the microstructural changes occurring during phase transitions of the azomethine. Spectral modifications, associated with molecular conformation rearrangements, allowing the change of the molecular shape from a LC organization to another, have been found. The spectral analysis gave significant evidences for the different phase transitions, thus proving the efficiency of such method for investigating LC materials.