Reactions of bis(isopropylxanthato)nickel(II) with nitrogen or oxygen donor ligands .3. X-ray crystal structure of the complex with pyrazine

Reactions of [Ni(Pr(i)xa)(2)] (Pr(i)xa = i-C(3)H7OCS(2)(-)) with nitrogen (pyr = 1,4-pyrazine, N,N-deen = N,N-diethylethylenediamine, N,N'-deen = N,N'-diethylethylenediamine or teen = N,N,N',N'-tertraethylethylenediamine) or oxygen (dmso = dimethyl sulfoxide) donor ligands resulted in the formation of the following compounds: [Ni(Pr(i)xa)(2)[pyr)](n), [Ni(Pr(i)xa)(2)(N,N-deen)], [Ni(Pr(i)xa)(2)(N,N'-deen)], [Ni[Pr(i)xa)(2)(teen)] and [Ni(Pr(i)xa)(2) (dmso)(2)]. All the complexes have been characterized by means of elemental analysis, UV-vis and IR spectroscopy, magnetochemical and conductivity measurements, and thermal analyses as octahedral complexes of bivalent nickel. The X-ray structure of [Ni(Pr(i)xa)(2) (pyr)](n) shows a linear chain structure in which the 1,4-pyrazine ligands form bridges among nickel(II) ions, which have trans-octahedral geometry. The distances among the nickel atoms in the linear chains are 7.085(1) Angstrom. The nearly constant value of the effective magnetic moment (3.03-3.08 mu(eff)/mu(B)) over the temperature range of 72-298 K indicated the absence of exchange interactions in polymeric [Ni(Pr(i)xa)(2)(pyr)](n). Copyright (C) 1996 Elsevier Science Ltd