Ab initio study of the photodissociation of nitrosoalkanes and nitrosamines

Abstract

The primary step of the photodissociation in CH3N0 and NH2NO has been investigated by ab initio SCF-CI techniques. The first singlet excited state presents a barrier along the dissociation coordinate both for CH3N0 and for the planar form of NH2N0. However, NH2N0 prefers a twisted and pyramidalized structure in SI, with no barrier to dissociation. These features of the SI surface explain the observation of a vibrational structure in the n - T* spectrum of (CH3)2NN0, dominate the dissociation mechanism (vibrational predissociation vs. intersystem crossing or internal conversion), and may influence the quantum yields in the condensed phase