First macrocyclic oxamide Cu(II)-Co(II) complex: synthesis, crystal structure and magnetic properties

A oxamido-bridged binuclear complex, [Cu(L)Co(bpy)(2)](ClO4)(2) . 0.5C(2)H(5)OH . H2O has been synthesized, and structurally and magnetically characterized, where L = 1,4,8,11-tetraazacyclotradecanne-2,3-dione and bpy = 2,2'-bipyridine. In the complex, the copper atom from the macrocyclic oxamido-copper(II) precursor in a square-planar and cobalt atoms in a distorted octahedral environment is bridged by the oxamidate group, Cu...Co separation of 5.359 Angstrom. The metal-metal separations are consistent with the sequence of decrease of the ion radius of the metal ion. The magnetic properties of the complex have been investigated. The chi(M)T versus T plots is typical of antiferromagnetically coupled Cu(II)-Co(II). (C) 2002 Elsevier Science B.V. All rights reserved.