Synthesis and structural characterisation of linear Au(I) N-heterocyclic carbene complexes: New analogues of the Au(I) phosphine drug Auranofin

The synthesis and characterisation of a series of neutral Au(I) N-heterocyclic carbene complexes [(NHC)AuX] (X = Cl and 2',3',4',.6'-tetra-O-acetyl-beta-D-glucopyranosyl-1-thiolato) are reported. The chloro complexes were synthesised either by reaction of the appropriate 1,3-dialkylimidazol-2-ylidene with [(Me2S)AuCl] or by transmetallation between the appropriate Ag(I)-NHC complex and [(Me2S)AuCl]. The 2',3',4',6'-tetra-O-acetyl-beta-D-glucopyranosyl-1-thiolato complexes were prepared from the appropriate [(NHC)Au(I)Cl] complex and 2',3,4,6'-tetra-O-acetyl-1-thio-beta-D-glucopyranose under basic conditions. A cationic Au(I)-NHC triphenylphosphine adduct was also prepared. Structural studies (X-ray diffraction) of a number of the complexes show that in each case the gold atom is (quasi-) linearly two-coordinate, having C-Au-Cl, C-Au-S or C-Au-P coordination. In one case, a new phase Of [Cy(2)Im)AuCl], the molecules pack pair-wise with a close Au...Au interaction (3. 1566(6) angstrom). Preliminary studies show this complex is luminescent in the solid state. (c) 2005 Elsevier B.V. All rights reserved.