The 1: 1 Adduct of 1,3-Diisopropyl-4,5-dimethyl-2,3-dihydroimidazol-2-ylidene and Nitrous Oxide

The nucleophilic carbene 1,3-diisopropyl-4,5-dimethyl-2,3-dihydroimidazol-2-ylidene (7) captures nitrous oxide under formation of both syn- (8) and anti-1,3-diisopropyl-4,5-imidazolium diazotate (9). The syn-isomer is the thermodynamically more stable form. As shown by X-ray crystallography, the two isomers are statistically distributed in the crystalline state.