AN AB-INITIO MOLECULAR-ORBITAL STUDY OF THE REACTION NH2-]H-2+N2O(NO)

Potential energy surface of the reaction NH2 + NO --> H-2 + N2O has be en studied at several high levels of ab initio molecular orbital theor y. The reaction pathway involves initially the formation without a bar rier of a twisted non-planar H2N-NO nitrosamine intermediate, and a C- s symmetry transition state, followed by a dihydrogen H, elimination t o form the products. The reaction path bifurcates before the transitio n state. At MP4(SDTQ)/6-311G(2d,p)//CASSCF/6-31G(d,p) level of theory, the reaction barrier for this path is found to be + 33.7 kcal/mol. (C ) 1998 Elsevier Science B.V.