Imine-coordinated 2-Aminoazole Complexes of Au(I): Complicating Reactions and Verification of Products by Crystal Structure Determination

Abstract

Abstract When Au(I) is provided with endocyclic soft thioether or endocyclic hard amine, endocyclic borderline imine and exocyclic hard amine coordination sites, the softer borderline endocyclic imine coordination site is favored. This is demonstrated by the synthesis and structural characterization (IR, MS, 1H, 13C and 31P NMR experiments and single-crystal X-ray diffraction analysis) of 2-aminoazole (2-amino-4-methylthiazole, 2-aminobenzothiazole and 2- aminobenzimidazole) complexes of [AuPPh3]+ (1-3). An unusual ring opening is observed for the reaction of 2-aminothiazoline with [Au(NO3)PPh3] yielding μ2-(2-mercapto-ethyl-cyanamide- k,S)bis(triphenylphosphine)gold(I) nitrate (4). Reactions of 2-aminoazoles with Au(C6F5)THT (THT=tetrahydrothiophene) yield [Au(C6F5)2]- stabilized by various cations. The formation of Au(2-aminothiazoline)C6F5 is again the exception