The trans influence and trans effect of the arsine group. The X-ray structures of dichloro[diphenyl(o-vinylphenyl)arsine]platinum(II) and [1-(o-diphenylarsinophenyl)-2-methoxyethyl-as,c1](hexafluoroacetylacetonato)platinum(II)

Abstract

The X-ray analyses of dichloro[diphenyl(o-vinylphenyl)arsine]platinum(II)(1) and a derivative (2) of nucleophilic attack by methoxide at its co-ordinated olefinic group are reported. Crystals of (1) are monoclinic, space group P2₁/c, with a= 9.288(3), b= 18.112(6), c= 12.413(4)Å, β= 118.33(2)°, and Z= 4. Crystals of (2) are orthorhombic, space group Pbca, with a= 24.178(7), b= 12.327(4), c= 18.500(6)Å, and Z= 8. Full-matrix least-squares refinement using diffractometer data (Mo-K_α; Pt, As, Cl, and F anisotropic) has given an R of 0.047 for 2 258 reflections for (1) and an R of 0.057 for 2 345 reflections for (2). In (1) the olefin group makes an angle of 83.6° with the co-ordination plane. In (2) there is a five-membered chelate ring containing a Pt–C σ bond and an exocyclic methoxy-group. A relatively high trans influence of the arsine group is inferred. The course of bridge-cleavage reactions of a related chloride-bridged demeric compound shows the trans effect of the arsine to be close to that of the alkyl carbon group.