Synthesis, Characterization of An Unsymmetrical Cu(II) Complex Liquid Crystal of a Schiff Base Containing a Terminal Double Bond

Abstract

The unsymmetrical Schiff base ligand 4-undecenyloxy-salicylidene-4-dodecyloxyaniline (Im-11–12) containing a terminal double bond derived from 4-undecenyloxysalicylaldehyde and 4-dodecyloxyaniline and its Cu(II) complex [Cu(Im-11–12)₂] were synthesized and characterized by elemental analyses, molar conductivity, IR, electronic spectra and ¹H NMR. The Schiff base functions as a uninegative bidentate ligand and bonds through oxygen and imino-nitrogen. The complex is a non-electrolyte and has a square planar geometry. The mesogenic behavior of the ligand and the complex was determined by a hot-stage polarized microscope and DSC. The transition processes of the ligand and the complex were tentatively proposed to include K→S→I, but their liquid crystalline texture structures were different.