Liquid crystalline properties of bis(salicylaldiminato)copper(II) complexes: the first columnar discotics derived from salicylaldimine Schiff bases

Abstract

The synthesis and mesomorphic properties of a homologous series ofN-(2-hydroxy-4-n-alkoxybenzylidene)-3′,4′-di-n-alkoxylanilines and their copper(ii) complexes bis[(N-3′,4′-dialkoxyphenyl)-4-n-alkoxylsalicylaldiminato]copper(ii) are reported. The disc-like copper complexes exhibited columnar hexagonal disordered mesophases, which were characterized by DSC analysis and optical polarized microscopy. The structure of the mesophases was confirmed by X-ray powder diffraction (XRD). The mesomorphic properties for these copper complexes were compared with other similar metallomesogenic bis(salicylaldiminato)copper(ii) complexes in terms of molecular structural differences.