Formation of autoionizing atomic nitrogen from superexcited states of nitric oxide

Photodissociation of NO followed by autoionization of an N atom has been studied by two-dimensional photoelectron spectroscopy using synchrotron radiation. In addition to the bands due to molecular ionization, the two-dimensional spectrum shows several characteristic patterns in the photon energy range of 21.5-27 eV which result from autoionization of the Rydberg states converging to N+(D-1(e)) into the ionic ground state N+(P-3(e)). The electronic states of the counter atomic oxygen can be determined from the lower onset energies of these patterns to be P-3(e) and/or D-1(e). Discussion is made about the transition region for the photodissociation reaction, especially being focused on the nature of the primary molecular states and their dynamical aspects including competitive molecular autoionization. (C) 1996 American Institute of Physics.