A crystalline C5-protonated 1,3-imidazol-4-ylidene

The first C5-protonated 1,3-imidazol-based mesoionic carbene iMIC(Bp) (2) (iMIC(Bp) = :C{CH(NDipp)(2)C(Bp)}; Dipp = 2,6-iPr(2)C(6)H(3); Bp = 4-PhC6H4) has been reported as a crystalline solid. Spectroscopic, X-ray diffraction, and computational studies clearly support the carbenic nature of 2, which has been further corroborated by its reactions with Ni(CO)(4), (Me2S)AuCl, white phosphorus, and CO2.