Novel octahedral nickel(II) dithiocarbamates with bi- or tetradentate N-donor ligands:: X-ray structures of [Ni(Bzppzdtc)(phen)2]ClO4•CHCl3 and [Ni(Bz2dtC)2(cyclam)]

A series of novel octahedral nickel(II) dithiocarbamate complexes involving bidentate nitrogen-donor ligands (phen = 1, 10-phenanthroline, bpy = 2,2'-bipyridine) or a tetradentate ligand (cyclam = 1,4,8,11-tetraazacycloteradecane) of the composition [Ni(BzMetdtc)(phen)(2)]ClO(4) (1), [Ni(Pe(2)dtc)(phen)(2)]ClO(4) (2), [Ni(Bzppzdtc)(phen)(2)]ClO(4) center dot CHCl(3) (3), [Ni(Bzppzdtc)(phen)(2)](SCN) (4), [Ni(BzMetdtc)(bpy)(2)]ClO(4) center dot 2H(2)O (5), [Ni(Pe(2)dtc)(cyclam)]ClO(4) (6), [Ni(BzMetdtC)(2)(cyclam)] (7), [Ni(Bz(2)dtC)(2)(cyclam)] (8) and [Ni(Bz(2)dtC)(2)(phen)] (9) (BzMetdtc = N,N-benzyl-methyldithiocarbamate(1-) anion, Pe(2)dtc = N,N-dipentyldithiocarbamate(1-) anion, Bz(2)dtc = N,N-dibenzyldithiocarbamate(1-) anion, Bzppzdtc = 4-benzylpiperazinedithiocarbamate(1-) anion), have been synthesized. Spectroscopic (electronic and infrared), magnetic moment and molar conductivity data, and thermal behaviour of the complexes are discussed. Single crystal X-ray analysis of 3 and 8 confirmed a distorted octahedral arrangement in the vicinity of the nickel atom with a N(4)S(2) donor set. They represent the first X-ray structures of such type complexes. The catalytic influence of complexes 2, 3, 6, and 7 on graphite oxidation was studied and discussed. (C) 2007 Elsevier Ltd. All rights reserved.