Synthesis and characterizations of Di- and tetranuclear copper(II) complexes

SUMMARY Synthesis and Chracterizations of Di- ve Tetranuclear Copper(II) Complexes Copper(II) complexes of novel tetraamin-tetrathioether and tetraoxime type ligands were synthesized and characterized by a combination of elemental analyses, 13C-, 'H-NMR, IR, UV-Vis, mass spectral studies and magnetic moments. These ligands are 6,6'-methylene- bis (5'-amino-3',4'-benzo-2'- thiapentyl) -141-diamino-2,3:9,10-dibenzo-4,8-dithiaundecane, (H4L), (4), 6,6'-bis(5'-amino-3'54'-benzo-2'-thiapentyl)-l,l l-diamino-2,3:9,10-dibenzo-4,8- dithiaundecane, (H4L1), (8) and 6,6'-methylene-bis(141-dmydroximino)-2,3:9,10-dibenzo- 4,8-dioxaundecane, (H4L2), (13). The geometry of the metal chelates is discussed with the help of magnetic and spectroscopic measurements. IR spectra showed that the ligand acts in a tetradentate manner and coordinates through the (C=N) and (NH2) and (-S-) groups. The elemental analyses, stoichiometry and the spectroscopic data of the complexes indicate that the copper(II) ions are coordinated by the ligand donor atoms. In addition, a geometric optimisation of the synthesized ligand 13 was made by method of molecular mechanics (MM2) in order to establish a stable conformation. The total energy for these conformations were calculated to be 10.94 and 9.49 kcal/mol. Keywords: Di and tetranuclear copper(II) complexes, tetratbiaether, tetraamin, tetraaldhyde, tetraoxime vn