Synthesis of copper (II) complexes incorporating N,N-dimethyl-N′-benzylethylenediamine and NCX (X = O, S and Se) ligands: A combined crystallographic, spectroscopic and DFT study

Three copper (II) complexes of type [Cu(L)2(NCX)]ClO4, 1–3, (L = N,N-dimethyl,N′-benzyl-1,2-diaminoethane and X = O, S and Se) were synthesized and characterized on the basis of microanalytical, spectroscopic and molar conductance. An X-ray diffraction study of [Cu(L)2(NCO)]ClO4 (1) reveals that the copper (II) center located in a distorted square pyramidal environment through coordination of four amine N atoms and a N atom of the terminal NCO−. Density functional theory (DFT) calculations were performed to understand the linkage isomerism of NCX− ligand from a theoretical point of view, to study the electronic structure of the complexes and the relative stabilities of the Cu–NCX/Cu–XCN isomers. DFT computational results buttressed the experimental observations indicating that the Cu–NCX isomer is more stable than Cu–XCN linkage isomer. Complexes 1 and 2 exhibit solvatochromism as evidenced from visible study in different solvents.

Mononuclear copper (II) pseudohalide (NCO, NCS and NCSe) complexes were synthesized. The X-ray showed structure around the copper in [Cu(L)2(NCO)]ClO4 is square pyramidal. DFT calculations show that the Cu–NCX complexes are more stable than their linkage isomers Cu–XCN. The complexes are soluble in organic solvents and demonstrated positive solvatochromism. The solvatochromic behaviors of the complexes are based on the DN value of the solvent.Figure optionsDownload as PowerPoint slide