Tris(pentafluorophenyl)gold(<scp>III</scp>) complexes

The preparation of [Au(C6F5)3(tht)](tht = tetrahydrothiophen) by oxidation of [Au(C6F5)(tht)] with [Tl(C6F5)2Cl] is described. Displacement of tht by other neutral or anionic unidentate ligands leads to the synthesis of [Au(C6F5)3L][L = NH3, py, PMePh2, P(OPh)3, AsPh3, SbPh3 or CNC6H4Me-p] or Q[Au(C6F5)3X][Q = NEt4, NBu4, PPh3(CH2Ph), or N(PPh3)2; X = Cl, I, SCN, or N3]. The compound [Au(C6H5)3(CNC6H4Me-p)] adds amines to give the gold(III)–carbene complexes [Au(C6F5)3{C(NHC6H4Me-p)(NR2)}](NR2= NHC6H4Me-p, NEt2, or NHCH2CH2NH2). The reaction of the compound [Au(C6F5)3(tht)] with potentially bidentate ligands takes two different courses. (a)o-Phenylenebis(dimethylarsine)(pdma) and 1,2-bis(diphenylphosphino)methane (dppm) give four-co-ordinated complexes, in which the ligands are unidentate; the pdma complex has inequivalent methyl hydrogens at low temperature (1H n.m.r.) and the dppm complex inequivalent P atoms (31P n.m.r.). An X-ray structure of the pdma complex confirms four-co-ordination in the solid state; space group P21/n, a= 10.796(3), b= 17.347(6), c= 16.275(5)Å, β= 94.47(3)°, Z= 4, R= 0.058 for 3 357 reflections. (b) 1,2-Bis(diphenylphosphino)ethane (dppe) acts as a bridging ligand leading to the formation of [(C6F5)3Au(µ-dppe)Au(C6F5)3]. Similar reactions starting from [Au(C6F5)(2,4,6-C6F3H2)2(tht)] lead to the compounds [Au(C6F5)(2,4,6-C6F3H2)2(PPh3)] or [NBu4][Au(C6F5)(2,4,6-C6F3H2)2Br]. The arylation of [Au(C6F5)3Cl]– or [Au(C6F5)(2,4,6-C6F3H2)2Br]– with Ag(C6F5) leads to [Au(C6F5)4]– and [Au(C6F5)2(2,4,6-C6F3H2)2]– respectively.