Synthesis, spectroscopic, electrochemical and structural characterization of Cu(II) complexes with asymmetric NN′OS coordination spheres
                                
                                    
                                        作者:Eulália Pereira、Lígia R. Gomes、John N. Low、Baltazar de Castro                                    
                                    
                                        DOI:10.1016/j.poly.2007.09.030
                                    
                                    
                                        日期:2008.1
                                    
                                    A set of four Cu(II) complexes, [Cu(cdnapen)], [Cu(cdnappd)], [Cu(cdMenappd)] and [Cu(cdMeMeOsalpd)], derived from Schiff base ligands with an asymmetric NN'OS coordination sphere have been synthesized. The molecular and the crystal structures have been determined by X-ray diffractometry. The structural results confirm that the complexes are tetra coordinated. The copper (II) ion coordinates to two nitrogen atoms from the imine moiety of the ligand, a sulfur atom from the methyl dithiocarboxylate moiety and a phenolic oxygen atom. The complexes show an unusual tetrahedral distortion to the square-planar geometry around the metal centre in spite of the pseudomacrocyclic skeleton of the ligand. The complexes were further characterized by cyclic voltammetry and electron paramagnetic resonance spectroscopy. The degree of tetrahedral distortion of the complexes appears to be dependent on the number of carbon atoms of the aliphatic bridge and the nature of the coordinating atoms. (C) 2007 Elsevier Ltd. All rights reserved.