Copper(II)-lanthanoid(III)-copper(II) trinuclear complexes with N,N′-bis(2-aminopropyl)-oxamido ligand

Six novel μ-oxamido trinuclear complexes, namely Cu₂(oxap)₂Ln(ClO₄)₃ (Ln: La, Pr, Nd, Gd, Yb, Ho), where oxap is N,N′-bis(2-aminopropyl)oxamido, have been synthesized. The complex Cu₂(oxap)₂Gd(ClO₄)₃ was characterized with variable temperature magnetic susceptibility (4—300 K). The exchange integrals J (Cu—Gd) and J′ (Cu–Cu) were found to be 0.83 cm^?1 and ?1.62 cm^?1, indicating that very weakly ferromagnetic spin-exchange interaction operates between Cu(II) and Gd (III) ions.