Abstract
Four binuclear Co(II), Ni(II) and Cu(II) complexes bridged by oxamidate (oxd) group have been synthesized, namely Co2(byp)2(oxd)(C104)2 (1), Co2(Me2bpy)2(oxd)(ClO4)2·H2O (2), Ni2(bpy)2(oxd)(ClO4)2·2H2O (3) and Cu2(Me2bpy)2(oxd)(NO3)2 (4). (bpy=2,2′‐bipyridyl, Me2‐bpy=4,4′‐dimethylbipyridyl, oxd=oxamidate) The complexes are characterized by IR, UV spectra, EPR and variable‐temperature magnetic susceptibility (4–300 K). The susceptibility data for complexes 1 and 3 were least‐squares fit to the susceptibility equation derived from the spin Hamiltonian Ȟ=‐2J · Š1·2. The exchange integral, J, was found to be equal to −3.62 cm−1 in 1 and −1.82 cm−1 in 3. This indicates a weak antiferromagnetic spin exchange interaction between the metal ions.