GOLD(I) COMPLEXES OF KETIMINOPHOSPHANES AND KETIMINOPHOSPHANE SULFIDES

The reactions of chloro(dimethyl sulfide)gold(I) with equivalent quant ities of the ketiminophosphane diphenyl(diphenylmethyleneamino)phospha ne (1a) or its sulfide (1aS) lead to high yields of stable, crystallin e 1:1 complexes with AuCl units attached to the phosphorus and sulfur atom, respectively. Tris(diphenylmethylene amino)phosphane (1c) gives the related complex (Ph2C=N)(3)PAuCl with the gold atom also selective ly P-bound. Bis(diphenylmethyleneamino)phenyl phosphane (1b) could not be used because of its limited stability. Single-crystal X-ray diffra ction studies have shown that there is no auxiliary coordination of th e metal center by the imino functions of the ligands. The geometry of the P/S-Au-Cl moieties deviates only very slightly from Linearity. The angle at the sulfur atom in (Ph2C=N)Ph2PSAuCl is very small [94.30(3) degrees], but despite of the resulting rather open coordination there are no discernible intra-or intermolecular contacts in the lattice. Su ch contacts are also absent with (Ph2C=N)Ph2PAuCl and (Ph2C=N)(3)PAuCl owing to the bulk of the ligands. The 1:1 complexes do not react with an excess of (Me2S)AuCl. This finding, and the molecular structures o f the 1:1 complexes, show very consistently that both phosphane and su lfide donors are far superior as ligands for gold(I) as compared to ke timine donor molecules.