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'-dipyridylami ne (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-P F6 compounds have also been isolated. The X-ray diffraction structures of t he [Cu(dipyam)(2)Br-2]. 2H(2)O (I) and the [Cu(dipyam)(2)Cl](2)I-2. 2CH(3)C N (II) complexes are reported. I is a rare example of an octahedral coordin ation 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-c omplex of approximately trigonal bipyramidal geometry, the dimerization bei ng due to hydrogen bonds formed by the NN group of one of the two dipyams c oordinated to each metal atom with the chlorine atom of the centrosymmetric cationic complex. The iodide anions are hydrogen-bonded to the NH groups o f the dipyams not involved in the dimerization. (C) 1999 Elsevier Science S .A. All rights reserved.