1 Centre for Research in Molecular Modeling and Department of Chemistry & Biochemistry, Concordia University, 7141 Sherbrooke Street West, Montreal, Quebec, Canada.

A combination of density-functional theory and natural resonance theory has been used to show that a complete description of the electronic structure of nitrilimines, R(1)CNNR(2), requires four resonance structures (propargylic, allenic, 1,3-dipolar and carbenic); appropriate substituents were shown to enhance the carbene character of nitrilimines to the point where they may be considered stable carbenes.