Investigations on the Liquid Crystalline Phase of Schiff's Base Complexes of Copper(II) and Their Corresponding Ligands

Some new liquid crystalline Schiff's base complexes with copper(II) have been prepared. Microscopic observations and D.S.C. measurements reveal broad nematic mesophases. X-ray investigations on magnetically oriented samples confirm the nematic mesophase and indicate a cybotactic one. Anisotropic magnetic susceptibility data of a mixture of Schiff's base complexes of copper(II) are presented. An orientation with the longitudinal axis parallel to the magnetic field is caused by the dominating diamagnetic anisotropy of the phenyl groups of these metallo-mesogens. The order parameter of bis[4-((4-hexyloxybenzoyloxy)-N−(4-butylphenyl)-salicylaldiminato] copper(II) solved in 5CB is investigated. Values up to S = 0.575 have been obtained. We report on D.S.C. measurements and microscopic observations on a series of N-(4-(4′ −n-alkoxybenzoyloxy)salicylidene)-4-n-alkyl-or alkyloxy-anilines. Temperature dependent X-ray investigations on magnetically oriented samples show skewed cybotactic nematic phases for these ligands.