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 [Au-III(damp-C-1,N) Cl-2] (damp-C,N- = dimethylaminomethylphenyl) with PhP(C6H3SH-2-SiMe3-3)(2), H2L, results in cleavage of the Au-C bond and the formation of [(AuLCl)-L-III] and [(AuL2AuIII)-L-I] complexes. The square coordination environment of gold in [AuLCl] is noticeably distorted (maximum deviation from planarity: 0.326(1) Angstrom) by the steric requirements of the tridentate chelating Ligand, but the oxidation state '+3' of the metal is retained. [(AuL2AuIII)-L-I] 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) Angstrom, indicative of a weak bonding interaction. (C) 1998 Elsevier Science S.A. All rights reserved.