SYNTHESIS, CHARACTERIZATION, AND PHASE-BEHAVIOR OF SOME AZINES WITH POTENTIAL OPTICAL NONLINEARITIES OF 2ND-ORDER

Some azines with potential nonlinear optical properties of the second order have been synthesised by condensation of the appropriate hydrazo nes and aldehydes. The compounds have been chemically functionalised t o allow their use in the synthesis of polymers containing the azine gr oups as side chain pendants. The characterisation of the phase behavio ur, performed by DSC, X-ray diffraction and polarising microscopy meth ods, shows that most of the compounds exhibit enantiotropic liquid cry stalline properties. Some peculiar features concerning solid state pol ymorphism have also been investigated.