Synthesis, Characterisation, and Phase Behaviour of Some Azines with Potential Optical Nonlinearities of Second Order

Some azines with potential nonlinear optical properties of the second order have been synthesised by condensation of the appropriate hydrazones and aldehydes. The compounds have been chemically functionalised to allow their use in the synthesis of polymers containing the azine groups as side chain pendants. The characterisation of the phase behaviour, performed by DSC, X-ray diffraction and polarising microscopy methods, shows that most of the compounds exhibit enantiotropic liquid crystalline properties. Some peculiar features concerning solid state polymorphism have also been investigated.