Synthesis, structures and properties of the dinuclear copper(II) complexes triply bridged by two oximato and one pyrazolato or one phthalazine

The triply (two oximato and one pyrazolato or one phthalazine) bridged dinuclear copper(II) complexes [Cu2(L1)2(pz)]ClO4 (1) and [Cu2(L1)2(phta)](ClO4)2 (2) (HL1=2-[2-(α-pyridyl)ethyl]imino-3-butanone oxime, pz=pyrazolate anion, phta=phthalazine) were synthesized and characterized; the crystal structures of 1 and 2 were determined by X-ray crystallography. Magnetic susceptibility measurements from liquid helium temperature to room temperature showed a weak antiferromagnetic exchange coupling between two copper(II) ions (2J=−17 cm−1) for l, on the other hand, a very strong antiferromagnetic interaction for 2 was observed (2J=−760 cm−1).