[{Cu(pzPh)(Opo)}2(μ-Cl)2]: A new dinuclear copper(II) complex with a chloride bridge and mixed blocking ligands

Abstract A new copper(II) complex with chloride bridges and mixed blocking ligands, [{Cu(pz Ph )(Opo)} 2 (μ-Cl) 2 ] ( 1 ), whereby pz Ph  = 3-phenyl-pyrazolyl, and OpoH = 2-hydroxypyridine- N -oxide, has been obtained by degrading tris(pyrazolyl)borate in the presence of hydrated CuCl 2 salt and the ligand Opo − . The molecular structure of 1 was solved by X-ray diffraction. The two Cu(II) atoms of the dinuclear complex have a pyramidal arrangement in which the two pyramids share one base-to-apex edge with parallel basal planes. Magnetic susceptibility measurements revealed ferromagnetic coupling between the Cu atoms, with J  = +8.72 cm −1 . X-band EPR spectra of CH 2 Cl 2 solutions of 1 were recorded at different temperatures.