Nucleophilic T-Shaped (LXL)Au(I)-Pincer Complexes: Protonation and Alkylation.

We report the synthesis and reactivity of unusual T-shaped (LXL)Au(I)-pincer complexes, based on a carbazole framework flanked by two mesoionic carbenes (MICs). In contrast to other Au(I) complexes, these complexes react with electrophiles. Protonation and alkylation occur either at the metal or the ligand, depending on steric factors. Of particular interest, protonation at gold leads to an unprecedented cationic Au(III) hydride, which gives a 1H NMR resonance at δ -8.34 ppm. The reactivity of this "hydride", however, shows protic and not hydridic behavior.