Synthesis, physicochemical and electrochemical studies on Mn(II), Co(II), Ni(II), and Co(II) complexes with an N-donor tetradentate (N4) macrocycle ligand derived from ethyl cinnamate

Manganese(II), cobalt(II), nickel(II), and copper(II) complexes with a new tetradentate ligand, 1,3,7,9-tetraaza-4,10-diketo-6,12-diphenyl-2,8-dithiocyclododecane (L), were synthesized and characterized by elemental analyses, molar conductance measurements, magnetic susceptibility measurements, mass, H-1 NMR, IR, electronic, EPR spectral and cyclic voltammetric studies. On the basis of the IR, electronic, and EPR spectral studies, an octahedral geometry has been assigned for the Mn(II) and Co(II) complexes, a square-planar one for the Ni(II) and a tetragonal one for the Cu(II) complexes.