Monomeric [Ni(2,2'-Bipy){(i-C4H9)(2)PS2}(2)] and [Ni(Pz)(2){(i-C4H9)(2)PS2}(2)] and polymeric [Ni(Pz){(i-C4H9)(2)PS2}(2)](n) complexes (Pz = pyrazine): Synthesis, structures, and properties

Diamagnetic [Ni(i-Bu2PS2)(2)] compound (I) in ethanol reacts with 2,2 ' -bi pyridine or pyrazine to give the paramagnetic complexes [Ni(2,2 ' -Bipy)(i- Bu2PS2)(2)] (II), [Ni(Pz)(2)(i-Bu2PS2)(2)] (III), and [Ni(Pz)(i-Bu2PS2)(2)] (n) (IV) (mu (eff) = 2.91-3.12 mu (B)). Single crystals of II were grown fo r X-ray diffraction study. The crystals are monoclinic, a = 14.669(3) Angst rom, b = 19.693(4) Angstrom, c = 12.155(2) Angstrom, beta = 107.51(3)degree s, V= 3348(1) Angstrom (3), Z = 4; rho (calcd) = 1.257 g/cm(3), space group P2(1)/c. The structure is built from monomeric molecules. The coordination polyhedron of the Ni atom is a distorted octahedron formed by four S atoms of two bidentate chelating i-BU2PS2- ligands and by two N atoms of bidenta te cyclic 2,2 ' -Bipy. Preliminary data for complexes III and IV indicate t hat they also contain an octahedral NiN2S4 fragment. The structures of comp lexes I (square planar) and of II-IV (octahedral) were confirmed by data fr om electron spectroscopy. Electronic absorption spectra were used to determ ine the rankings of the i-Bu2PS2- ions and Pz on a spectrochemical scale.