Complexes with sulphur and selenium donor ligands. Part 7. The crystal and molecular structure of bis(diphenylphosphinodithioato)-cobalt(II)–quinoline (1/1)

Abstract

The title complex has been characterised and its crystal and molecular structure solved by diffractometric methods. Turquoise crystals of formula [Co(S₂PPh₂)₂]·C₉H₇N obtained from chloroform solution are orthorhombic, space group Fdd2, with unit-cell dimensions a= 23.528(2), b= 28.690(2), c= 9.571(1)Å, and Z= 8. The structure has been refined by least-squares methods using 964 independent reflections, to a conventional R of 0.065. The structure is monomeric and the co-ordination about the cobalt is slightly distorted trigonal bipyramidal, the quinoline molecule lying in the equatorial plane. The axial and equatorial Co–S distances are very different, (Co–S_ax)-(Co–S_eq)= 0.30 Å(3σ 0.018 Å). This difference is reflected in the shorter P–S_ax distance, which although just statistically significant (0.04 Å shorter than P–S_eq., 3σ 0.018 Å). leads to an observable difference in the ν_asym(PS) band in the i.r. spectrum of the quinoline adduct and the parent [Co(S₂PPh₂)₂]. The electronic spectra and magnetism of the complex are briefly discussed.