Synthesis and mesomorphism of new chiral imines and copper(II) complexes

The synthesis, characterization and mesomorphic properties of a series of N-(2-hydroxy-4-n-alkyloxybenzylidene) 4'-amino-2-methylbutylcinnamate and their copper(II) complexes are reported. The imines exhibited smectic A (SmA) and chiral smectic C (SmC*) phases while their copper(II) complexes displayed SmA-SmC phase variant. The compounds have been characterized by elemental analysis and spectroscopic studies. The phase transition temperatures were detected by differential scanning calorimetry (DSC) analysis and the phases are confirmed by polarizing optical microscopy (POM). The chiral phase (SmC*) of the ligand disappeared on complexation. The unwinding of the helical superstructure of SmC* phase under the influence of electric field and the observed optical textures of SmC* phase are also discussed. (C) 2013 Elsevier B.V. All rights reserved.