Gold(I) complexes bearing N-heterocyclic carbenes (NHC) of the type (NHC)AuBr (3a/3b) [NHC = 1-methyl-3-benzylimidazol-2-ylidene (= MeBnIm), and 1,3-dibenzylimidazol-2-ylidene (= Bn2Im)] are prepared by transmetallation reactions of (tht)AuBr (tht = tetrahydrothiophene) and (NHC)AgBr (2a/2b). The homoleptic, ionic complexes [(NHC)2Au]Br (6a/6b) are synthesized by the reaction with free carbene. Successive oxidation of 3a/3b and 6a/6b with bromine gave the respective (NHC)AuBr3 (4a/4b) and [(NHC)2AuBr2]Br (7a/7b) in good overall yields as yellow powders. All complexes were characterized by NMR spectroscopy, mass spectrometry, elemental analysis and single crystal X-ray diffraction. Reactions of the Au(III) complexes towards anionic ligands like carboxylates, phenolates and thiophenolates were investigated and result in a complete or partial reduction to a Au(I) complex. Irradiation of the Au(III) complexes with UV light yield the Au(I) congeners in a clean photo-reaction.
金(I)配合物,含有N-杂环卡宾(NHC),类型为(NHC)AuBr (3a/3b) [NHC = 1-甲基-3-苄基
咪唑-2-亚基(= MeBnIm),以及1,3-二苄基
咪唑-2-亚基(= Bn2Im)],通过(tht)AuBr (tht =
四氢噻吩)和(NHC)AgBr (2a/2b)的转
金属反应制备。通过与自由卡宾反应,合成了同配位离子型配合物[(NHC)2Au]Br (6a/6b)。3a/3b和6a/6b依次用
溴氧化,以黄色粉末形式得到了良好的整体产率的相应(NHC)
AuBr3 (4a/4b)和[(NHC)2AuBr2]Br (7a/7b)。所有配合物都通过NMR光谱学、质谱学、元素分析和单晶X射线衍射进行了表征。研究了Au(III)配合物对
羧酸盐、
酚盐和
硫酚盐等阴离子
配体的反应,并导致了完全或部分还原为Au(I)配合物。Au(III)配合物用UV光照射,在干净的光反应中产生了Au(I)同类物。