Six novel μ-oxamido heterobinuclear complexes, namely Cu(oxap)Ln(NO2-phen)2.(ClO4)3, where oxap denotes N, N'-bis (2- aminopropyl) oxamido dianion, NO2-phen represents 5-nitro-1, 10- phenanthroline and Ln stands for La, Nd, Eu, Gd, Dy, Ho, have been synthesized and characterized. The variable-temperature magnetic susceptibility of Cu.(oxap)Gd(NO2-phen)2(ClO4)3 were measured over 4~300K and the susceptibility data were least-squares fit to the susceptibility equation derived from the spin Hamiltonian operator H=-2JS1.S2. The exchange integral was found to be 1.15cm^-^1, indicating that a weaker ferromagnetic spin-exchange interaction operates between the metal ions. The weaker interaction can be interpreted using the spin-polarization theory.

Key words: COPPER COMPLEX, HOLMIUM COMPLEX, DINUCLEAR COMPLEX, EUROPIUM COMPLEX, LANTHANUM COMPLEX, NEODYMIUM COMPLEX, PHENANTHROLINE P, MAGNETISM, OXAMATO COMPLEXES, DYSPROSIUM COMPLEX