Selective Nitrobenzene Reduction Catalyzed by Small and Monodisperse Triimidazotriazinylidene Carbene-Protected Gold Nanoparticles

Small (NHC)-stabilized Au nanoparticles 2.52 nm in size and nearly monodisperse can be readily and reproducibly synthesized starting from a triimidazotriazine functionalized by N-alkylation with benzylbromide. Subsequent ionic exchange with [AuCl4]- and reduction of the resulting imidazolium tetrachloroaurate affords new (NHC)-protected Au nanoparticles. These nanoparticles can be readily adsorbed on commercial titania affording a catalyst of exceptional activity and selectivity in the reduction of nitrobenzene to aniline at room temperature and ambient pressure.