The crystal and molecular structure of bis{−(μ-sulphato-O′-O′-O″)bis (triphenylphosphine) (sulphurdioxide)ruthenium(II)}} · (toluene) [Ru(SO4)(SO2)(PPh3)2]2 · (C7H8)

The preparation and structure of the title compound, [Ru(SO4)(SO2)(PPh3)2]2, is reported. The compound is formed in low yield when SO2 is passed through a solution of RuH2(PPh3)4 in toluene. The structure has been determined using diffractometer data and refined by least-squares techniques to R=0.078 based on 2669 observed intensities. The crystals are orthorhombic, Pbca (D 2h 15 ), with unit cell dimensionsa=17.635(7) A,b=18.874(7) A,c=21.631(7) A; Z=4. The coordination geometry about the ruthenium is a distorted octahedron with the triphenylphosphine ligands occupyingcis-coordination sites. The sulphato group is bidentate with respect to any particular metal atom, and additionally utilises a third oxygen atom to link two coordination centres to give a dimeric structure. The remaining coordination site is occupied by a sulphur dioxide ligand bonded in aη1-planar coordination mode with Ru-S equal to 2.107(5) A. This crystal structure analysis has assisted in formulating the primary product of the reaction of SO2 with RuH2 (PPh3)4 as Ru(SO4)(SO2)(PPh3)2(H2O).