Synthesis and Magnetic Studies of Copper (II)-Manganese (II) Heterobinuclear Complexes with an Oxamido Bridge
Abstract
Four new copper (II)-manganese (II) heterobinuclear complexes bridged byN, N'-bis[2-(dimethylamino)ethyl)]oxamido dianion (dmoxæ) and end-capped with 1, 10-phenanthroline (phen), 5-methyl-1, 10-phenanthroline (Mephen), diaminoethane (en) or 1,3-di-aminopropane (pn). respectively, namely, [Cu(dmoxae)MnL2] (CIO4)2 (L=phen, Mephen, en, pn), have been synthesized and characterized by elemental analyses, IR, electronic spectral studies, and molar conductivity measurements. The electronic reflectance spectrum indicates the presence of spin exchange-coupling interaction between bridged copper(II) and manganese (II) ions. The cryomagnetic measurements (4.2-300 K) of [Cu(dmoxae)Mn(phen)2](CIO4)2 (1) and [Cu(dmoxae)Mn(Mephen)2](CIO4)2(2) complexes demonstrated an antiferromagnetic interaction between the adjacent manganese(II) and copper (II) ions through the oxamido-bridge within each molecule. On the basis of spin Hamiltonian, H= - 2JS1. S2. the magnetic analysis was carried out for the two complexes and the spin-coupling constant (J) was evaluated as −35.9 cm−1 for 1 and - 32.6 cm−1 for 2. The influence of methyl substitutions in the amine groups of the bridging ligand on magnetic interactions between the metal ions of this kind of complexes is also discussed.
