A versatile gold synthon for acetylene C-H bond activation

The reaction of N, N '-bis(2,6-diisopropylphenyl) imidazol-2-ylidene gold hydroxide ([Au(OH)(IPr)]; 1) with acetylene and trimethylsilylacetylene derivatives cleanly leads to the formation of a gold-acetylide bond with the concomitant formation of water or trimethylsilanol. All compounds were isolated in high yield (> 85%). The crystal structures of selected gold acetylides in conjunction with their UV-vis absorption/emission properties were investigated. Finally, DFT calculations were performed in an attempt to gain an insight into the mechanism of the general reaction.