Stabilisation of Au and Au in the same complex molecule by a tridentate phosphinodithiolate ligand. Structures of [AuLCl] and [AuL2Au] (L = {PhP(C6H3S-2-SiMe3-3)2})

The reaction of the organometallic complex Au^III(damp-C^I,N)Cl₂] (damp-C,N⁻ = dimethylaminomethylphenyl) with PhP(C₆H₃SH-2-SiMe₃-3) ₂, H₂L, results in cleavage of the AuC bond and the formation of Au^IIILCl] and Au^IL₂Au^III] complexes. The square coordination environment of gold in AuLCl] is noticeably distorted (maximum deviation from planarity: 0.326(1) Å) by the steric requirements of the tridentate chelating ligand, but the oxidation state ‘+3’ of the metal is retained. Au^IL₂Au^III] contains gold atoms in both square-planar (Au^III) and linear (Au^I) coordination environments. The square-planar Au^III is bound by two trans-chelated PS units, and the two remaining thiolate groups provide the linear coordination of Au^I. The Au-Au distance is 2.919(1) Å, indicative of a weak bonding interaction.