Crystal and molecular structures of two triphenyllead xanthates, Ph₃Pb(S₂COR), R = Me and i-Pr, featuring weak intramolecular Pb … O interactions

Abstract

The crystal structure of Ph₃Pb(S₂COMe) (1) features a tetrahedrally coordinated lead centre existing within a distorted tetrahedral geometry defined by three ipso-carbon atoms and a sulphur atom derived from a monodentate xanthate ligand. The xanthate ligand is orientated to place the oxygen atom in close proximity to the lead atom rather than the formally thione-sulphur atom. The structure of Ph₃Pb(S₂CO-i-Pr) (2) comprises three independent molecules that differ from each other only in the relative orientations of the lead-bound phenyl groups, the distorted tetrahedral coordination geometries and orientation of the xanthate ligand resembles that observed in (1). Globally, the crystal structures are similar in that they both comprise supramolecular layers of molecules self-assembled through C—H … π(aryl) contacts. Crystal data for (1): monoclinic, Cc, a = 17.614(4), b = 8.4270(18), c = 15.392(4) Å, β = 120.351(3)°, V = 1971.5(8) ų, Z = 4, R = 0.028. Crystal data for (2): triclinic, P-1, a = 10.0922(11), b = 12.1182(12), c = 26.815(3) Å, α = 91.741(9), β = 96.406(9), γ = 96.768(9)°, V = 3233.1(6) ų, Z = 6, R = 0.037.