Electronic and molecular structure of aminimides (1-acyl-2,2,2-trimethyldiazan-2-ium-1-ide). 1. Formaminimide (HCON- N+ Me3).

The electronic structure and geometries of (Z)- and (E)-H-CON- N+(CH3)3 have been examined at two levels of theory: B3LYP (basis sets 6-311+G(d,p), 6-311++G(d,p), and 6-311G(3df,3pd)) and MP2(full)/6-311++G(d,p). The (Z) conformation about the C(O)-N(-) bond is thermodynamically preferred over the (E) configuration. Natural bond orbital calculation locates one lone pair of the N- in the HOMO, which is the p(z) natural hybrid orbital (perpendicular to the O=CN- N+ plane).