MESOGENIC PROPERTIES OF NOVEL ENAMINO KETONE LIGANDS AND THEIR COPPER(II) COMPLEXES

Several novel homologous series of ligands incorporating an enamino ke tone quasi-ring and their copper complexes are synthesized and studied by thermal microscopy, DSC and EPR methods. The ligands xyphenyloazo) phenyl]-3-alkylaminoprop-2-en-1-ones} and their complexes form enantio tropic nematic and smectic C phases with the nematic phase of. some of the complexes broader than 80 degrees C. The EPR spectra of the param agnetic complexes show that the chelate centre is planar in dilute sol ution as well as in the magnetically concentrated smectic C phase. Exc hanging the hexyloxy moiety for a hexylamino or N-hexyl-N-methylamino group gives a series of ligands and complexes with lower melting and c learing temperatures. Further molecular modifications including a reve rsal of the substitution pattern on the enamino ketone ring;are also p resented.