SYNTHESIS, CHARACTERIZATION AND REDOX BEHAVIOUR OF MIXED LIGAND COPPER(II) SACCHARINATE COMPLEXES

Abstract

Three mixed-­ligand complexes of Cu(II) with saccharin (sac), pyrazole, (Hpz), imidazole, (Himid) were synthesized and characterized on the basis of elemental analysis, FT-­IR spectroscopy, magnetic susceptibility, EPR spectra, and X-­ray diffraction. The reaction of [Cu(sac)2(H2O)4] ⋅ 2H2O with pyrazol in methanol resulted in a mononuclear pentacoordinated compound [Cu(sac)2(Hpz)3] (1) and a trinuclear N,N.bridged compound [Cu3(sac)2(Hpz)3(pz)3)2(OH)] (2), forming a nine membered [-Cu-­N-­N-­]3 ring and μμ3-­‐‐OH bridge; each Cu(II) ion is tetracoordinated, with weak axial interactions from saccharinate ions.The Himidazole compound [Cu2(sac)4(Himid)4] (3) has a dinuclear structure with two saccharinate ions as bridge; each Cu(II) ions has a penta-­coordination sphere, two N-­coordinated and one O-­coordinated saccharinate ions on the equatorial plane, and two imidazole molecules in the axial positions.