Synthesis and thermal behaviour of mesomorphic CuII Schiff's base complexes

Abstract

Three series of Schiff's bases, namely 2-(4-alkoxy-2-hydroxybenzylideneamino)fluorenes (1), 4-(4-alkoxy-2-hydroxybenzylideneamino)biphenyls (2), 4-(4-alkoxy-2-hydroxybenzylideneamino)stilbenes (3), (where the number of carbon atoms in the alkoxy chain, n, varies from 4 to 10) and the corresponding Cu^II complexes (4, 5 and 6, respectively) have been synthesized. The thermal behaviour of all the ligands and the complexes was investigated by means of polarizing microscopy and differential scanning calorimetry. While the ligands exhibit both nematic and smectic mesophases, the Cu^II complexes exhibit only a smectic mesophase. The electronic and emission spectra are also presented.