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 [CuI(H2CPz2)(MeCN)2](ClO4) (1) and [CuII(H2CPz2)2(ClO4)2]
(4), a novel ferromagnetic ClO4--bridged bis(μ-hydroxo)dicopper(II) complex, [Cu2(H2CPz2)2(OH)2(ClO4)](ClO4)(CH3CN)0.5 (5), and a bischelated copper(I) complex, [Cu(H2CPz2)2](ClO4) (2), prepared from a one-pot reaction of
[Cu(MeCN)4](ClO4) and H2CPz2, 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) Å), leading to the dissociation of one MeCN to form a Y-shaped complex, [CuI(H2CPz2)(MeCN)](ClO4) (3),
which is oxidized readily in air to form complex 5 with a butterfly Cu2O2 core.