CRYSTAL-STRUCTURES OF [NBU4(N)]2[M(C3S5)(C3SE5)] (M = NI OR PD) AND PROPERTIES OF THE NICKEL(II) COMPLEX

The complexes [NBu(n)4]2[M(C3S5)(C3Se5)] (M = Ni 1 or Pd 2) were isolated. Oxidation reactions of 1 with [Fe(C5H5)2] [PF6], [Fe(C5Me5),] [BF4] and [ttf]3[BF4], (ttf.+ = the radical cation of tetrathiafulvalene) and the current-controlled electrolysis of 1 afforded partially oxidized complexes [NBu(n)4]0.7[Ni(C3S5)(C3Se5)], [Fe(C5Me5)2]0.7[Ni(C3S5)(C3Se5)], [ttf]0.7[Ni(C3S5)(C3Se5)] and [NBu(n)4]0.3-[Ni(C3S5)(C3Se5)], respectively. These partially oxidized complexes have electrical conductivities of 4.2 x 10(-1)-5.5 x 10(-5) S cm-1 at 25-degrees-C for compacted pellets. Cyclic voltammetry and electronic absorption spectra of 1, together with IR, ESR and powder reflectance spectra of the partially oxidized species, are discussed. Single-crystal X-ray structure analyses of 1 and 2 reveal that the anions are separately arranged in the crystal phase and that the metal atoms are located at centres of symmetry, the positions of the S and Se atoms being disordered. The monoclinic crystals, space group P2(1)/c, have cell dimensions a = 8.498(5), b = 14.981(6), c = 19.620(7) angstrom, beta = 96.13(4)-degrees and Z = 2 for 1 and a =8.5837(5), b = 15.012(l), c = 19.717(3) angstrom, beta = 96.31(1)-degrees and Z = 2 for 2. Block-diagonal least-squares refinements, based on 1825 and 2723 reflections [\F(o)\ > 3-sigma(F)], converged at R = 0.076 and 0.062 for 1 and 2, respectively.