Single crystal studies of tetra-n-butylammoniumnickel (o-benzene-diselenolate)2 and related transition metal complexes: possible synthetic metal precursors

Abstract Preliminary low temperature X-ray diffraction studies of single crystals of the tetra-n-butylammonium salt of nickel (o-benzenediselenolate (bds)) 2 confirm the presence of a low temperature crystalline phase transition. At 155(±2) K, a superlattice forms along the c crystalline axis. Variable temperature single crystal ESR studies reveal a very sharp change (i.e., less than 1 K in width) in two of the principal components of the g-tensor at 155(±2) K for the (n-Bu) 4 N + Ni(bds) 2 − salt. Neither single crystal or polycrystalline ESR studies of the corresponding sulfur substituted salt gives evidence for a crystalline phase transition between 80 and 300 K. Although both salts are isomorphic at room temperature. Temperature dependent ESR studies of single crystals of (n-Bu) 4 N + Ni s 2 − and tetra-n-butylammonium nickel (o-benzenedithiolate(bdt) 2 reveal that the g-tensors for both the bds and bdt salts are orthorhombic. Whereas, ESR studies on polycrystalline samples suggest that the bdt salt is orthorhombic and the bds salt is axial. The two sets of measurements are consistent due to the poorer ESR spectral resolution possible when studying polycrystalline samples.