Synthesis, spectroscopic characterization, single crystal X-ray structure and packing analyses of [Cu(temed)(p-nitro-cinnamate)2] and [Cu(temed)(p-methoxy-cinnamate)2

Abstract

Two new copper(II) complexes; [Cu(temed)(p-nitro-cinnamate)2] (1), [Cu(temed)(p-methoxy-cinnamate)2] (2), where temed = N,N,N′,N'-tetramethylethylenediamine, have been synthesized by reacting appropriate starting materials using methanol-water (4:1 v/v) as solvent at room temperature. Both newly synthesized copper(II) cinnamate complexes have been characterized on the basis of elemental analyses, spectroscopic techniques (FT-IR, UV–visible, EPR) and single crystal X-ray structure determination. X-ray structure determination of both complexes revealed the existence of neutral structure of both complexes. p-Nitrocinnamate and p-methoxycinnamte exhibited similar (asymmetric chelating) coordination mode of carboxylate ligand towards copper(II) metal centre. Various non-covalent intermolecular interactions such as C-H∙∙∙O have also been observed that play an important role in crystal lattice stabilization of complexes 1 and 2. The EPR spectroscopy on the basis of axial symmetry of g tensor components suggested tetragonally elongated octahedral geometry of the complexes which is consistent with X-ray structure determination.