Complexes of copper(II) dihalide with 2,2′-dipyridylamine.: X-ray diffraction structures of the [dibromo-bis(dipyam)copper(II)]-water (1:2) and di[chloro-bis(dipyam)copper(II)]diiodide- acetonitrile (1:2) complexes

The formation of complexes between copper(II) halides and 2,2'-dipyridylamine (dipyam) has been studied systematically. Only complexes with a 1:1 and 1:2 metal-to-ligand ratio are formed. Some mixed chloro-iodide and halide-PF6 compounds have also been isolated. The X-ray diffraction structures of the [Cu(dipyam)(2)Br-2]. 2H(2)O (I) and the [Cu(dipyam)(2)Cl](2)I-2. 2CH(3)CN (II) complexes are reported. I is a rare example of an octahedral coordination among the copper(II) halide complexes of dipyam. The two bromo atoms, which occupy the apical positions, are H-bonded to the water molecules of crystallization. It is a dimer, where each copper forms a cationic chloro-complex of approximately trigonal bipyramidal geometry, the dimerization being due to hydrogen bonds formed by the NN group of one of the two dipyams coordinated to each metal atom with the chlorine atom of the centrosymmetric cationic complex. The iodide anions are hydrogen-bonded to the NH groups of the dipyams not involved in the dimerization. (C) 1999 Elsevier Science S.A. All rights reserved.