Thermal, optical, electrical and structural study of new symmetrical azomethine based on poly(1,4-butanediol)bis(4-aminobenzoate)

The synthesis, characterization and mesomorphism of new thermotropic imine prepared via condensation of biphenyl-4-carboxaldehyde with poly(1,4-butanediol)bis(4-aminobenzoate) was reported. The structure of imine was characterized by means FTIR, 1H, 13C NMR spectroscopy and elemental analysis; the results show an agreement with the proposed structure. The differential scanning calorimetry, polarizing optical microscopy and X-ray diffraction (WAXRD, SAXRD) were employed to evaluate their phase transitional behavior. The imine exhibited smectic A (SmA) and smectic B (SmB) mesophases. Liquid crystalline properties of the azomethine were studied additionally via UV–vis spectroscopy in the function of temperature (UV–vis(T)). The compound has one emission band at 360 nm and thermoluminescence emission occurs at about 500–600 nm wavelengths. Current–voltage measurements were performed on ITO/AZ/Alq3/Al device with three different thickness of the film.