Stabilisation of AuIII and AuI in the same complex molecule by a tridentate phosphinodithiolate ligand. Structures of [AuIIILCl] and [AuIL2AuIII] (L = {PhP(C6H3S-2-SiMe3-3)2}2−)

The reaction of the organometallic complex [AuIII(damp-CI,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 [AuIIILCl] and [AuIL2AuIII] complexes. The square coordination environment of gold in [AuLCl] is noticeably distorted (maximum deviation from planarity: 0.326(1) A) by the steric requirements of the tridentate chelating ligand, but the oxidation state ‘+3’ of the metal is retained. [AuIL2AuIII] contains gold atoms in both square-planar (AuIII) and linear (AuI) coordination environments. The square-planar AuIII is bound by two trans-chelated PS units, and the two remaining thiolate groups provide the linear coordination of AuI. The Au-Au distance is 2.919(1) A, indicative of a weak bonding interaction.