INFLUENCE OF LATERAL ALKOXY SUBSTITUTION ON MESOMORPHIC PROPERTIES OFCOPPER-COMPLEXES

Coordination complexes between copper and some lateral alkoxy chain-su bstituted 4'-alkoxybenzoyloxy)salicylidene)-4-n-butylaniline have been synthesized. The lateral chain was introduced on the outer ring beari ng the ester function. In the case of a 3,4-disubstitution, the mesomo rphic behavior is related to the number of carbons in the terminal cha in. If this is too small, the mesomorphic properties of the complexes disappear. In contrast, copper complexes are liquid crystalline and sh ow more ordered phases by comparison with the free ligand. In case of a 2,4-disubstitution, the phases are nematic and the clearing temperat ures are near room temperature, but the observed phases are essentiall y monotropic for the ligands, as well as for the complexes.