First example of a 2:1 cocrystal of mixed Cu(I)/Cu(II) complexes and a novel ferromagnetic bis(μ-hydroxo)dicopper(II) complex with a bis(pyrazol-1-yl)methane bidentate ligand

A unique 2:1 cocrystal of mixed Cu(I)/Cu(II) complexes [Cu-1(H(2)CPz(2))(MeCN)(2)](ClO4) (1) and [Cu-11(H(2)CPz(2))(2)(ClO4)(2)] (4), a novel ferromagnetic ClO4--bridged bis(mu-hydroxo)dicopper(II) complex, [CU2(H(2)CPz(2))(2)(OH)(2)(ClO4)](ClO4)(CH3-CN)(0.5) (5), and a bischelated copper(I) complex, [Cu(H(2)CPz(2))(2)](ClO4) (2), prepared from a one-pot reaction of [Cu(MeCN)(4)](ClO4) and H(2)CPz(2), are described. The structures of these complexes have been determined by X-ray crystallographic methods. The Cu(I)-N(acetonitrile) bond distances in complex 1 are nonequivalent (1.907(8) and 2.034(9) Angstrom), leading to the dissociation of one MeCN to form a Y-shaped complex, [Cu-1(H(2)CPz(2))(MeCN)](ClO4) (3), which is oxidized readily in air to form complex 5 with a butterfly CU2O2 core.