Reactions between Cu(II) halide complexes of 2,2-dipyridylamine and nitrophenolates.: X-ray diffraction structure of the [bis(2,2′-dipyridylamine)di(p-nitrophenolato)di(μ-methoxo)dicopper(II)], [Cu(dipyam)(pnp)(μ-OCH3)]2, a dimeric complex containing axial phenoxo ligands in square-pyramidal arrangements

The reaction between the [Cu(dipyam)Br-2] Complex (dipyam = 2,2'-dipyridylamine) and nitrophenolates gave products of exchange reactions between halides and phenolates. Starting from [Cu-2(dipyam)(2)(OH)(2)(H2O)]Cl-2.2H(2)O, o- and p-nitrophenolate complexes with the same rough formula Cu(dipyam)(OR)(OCH3) (OR = o- or p-nitrophenolate) but a different chemical behaviour have been obtained. The X-ray diffraction analysis shows that the derivative of the p-nitrophenolate is an interesting dimer [Cu(dipyam)(pnp)(mu-OCH3)](2) (pnp = p-nitrophenolate), with two centrosymmetrically related five-coordinated copper(H) ions, having a distorted square-pyramidal geometry defined by axial phenolate ligands and by equatorial dipyam nitrogens and mu-methoxo oxygen bridges. The bridging arrangement forms a Cu2O2 core, with a Cu...Cu separation of 3.062(2) Angstrom. The crystal structures of the [Cu(dipyam)(pnp)(2)].2H(2)O and [Cu(dipyam)(onp)(2)] complexes (onp = o-nitrophenolate) are also reported. (C) 2003 Elsevier Science B.V. All rights reserved.