Ferromagnetic oxalato-bridged zigzag chain Cu(II) compound capped with an aliphatic bidentate ligand

A new 1D oxalato-bridged complex [Cu(tmen)(ox)]n · 4nH2O (1) (ox = oxalate) chelated with aliphatic bidentate ligand tmen (tmen = N,N,N′,N′-tetramethylethylenediamine) have been prepared and characterized by means of X-ray analysis and magnetic measurements. The X-ray structure shows that Cu(II) centers are linked in a bis-bidentate mode of ox, generating a zigzag chain disposition. The magnetic data for 1 were fitted with the Baker equation derived from the Hamiltonian H = −J∑i Si · Si + 1, exhibiting ferromagnetic interactions with J = 0.30 cm−1 that are evaluated by a MO calculation using a spin dimer model.