Macrocyclic Complexes. III. Synthesis and Characterizatiok of Cobalt(II), Nickel(II), and Copper(II) Complexes of [16]-1, 4, 5, 8, 9, 12, 13, 16-Octaaza-1, 4, 6, 7, 9, 12, 14, 16-Octahydro-2, 3, 10, 11-Tetraoxo-Cyclohexadecane-5, 7, 13, 15-Tetraene (Otcht)

Abstract

A series of macrocyclic complexes of the titled ligand with Co(II), Ni(II) and Cu(II) have been prepared by the action of glyoxal on bis(1, 4-diamino-1, 4-diaza-2, 3, dioxobutane) chelates of Co(II), Ni(II) and Cu(II) The coordination template effect governs the steric course of the reaction. The structures of the complexes have been elucidated on the basis of IR, electronic and ESR spectral data, magnetic properties and electrochemical studies All the complexes give two well-defined reduction curves corresponding to the formation of a species where the metal can be formally assigned to an oxidation state of +1 or zero, respectively The X-ray diffraction pattern suggests a tetragonal structure for the Co(II) and Ni(II) and an orthorhombic structure for the Cu(II) macrocyclic complexes.