Syntheses, Structure, and Properties of Several Bis(O,O′–dialkyl dithiophosphato)cobalt(II)Adducts

Abstract
Several amine or phosphine adducts of bis (O,O′-dialkyl dithiophosphato)cobalt(II), which were hardly oxidized in air at room temperature, were obtained as crystalline solids. The crystal and molecular structure of one adduct, Co(Me2dtp)2(triphenylphosphine) (Me2dtp=O,O′-dimethyl dithiophosphato group), was determined by means of the X-ray diffraction method. The crystal is monoclinic: space group P21/n, a=26.712(4), b=9.495(1), c=11.180(5) Å, β=95.43(3)°, Z=4, Dx=1.495, Dm=1.45 g cm−3, μ(Mo Kα)=1.17 mm−1, and the final R value obtained is 0.062 for 4466 observed reflections. The coordinated atoms around the cobalt atom are in a trigonal bipyramidal configuration. The approximate first formation constants of the adducts, K=[Co(II)(R2dtp)2·X]/{[Co(II)(R2dtp)2][X]} (R=alkyl group, and X=donor) in solution, were obtained by means of the spectrophotometric as well as the NMR technique.