Fragmentation of vibrationally selected N2O+ in state (C)over-tilde 2Σ+ from measurements of threshold photoelectron photoion coincidence

Dissociation of vibrationally selected N2O+ in state (C) over tilde(2)Sigma(+) has been investigated with a threshold photoelectron-photoion coincidence technique in pulsed mode and with synchrotron radiation. Branching ratios and average releases of kinetic energy in channels of formation of fragments N+, O+, N-2(+), and NO+ at a level below the threshold of state (C) over tilde>(2)Sigma(+), and in levels (0,0,0), (1,0,0), and (0,0,1) of that state, were obtained from well-resolved time-of-flight peaks, fitted to Gaussian shape, in the coincidence mass spectra. The results show a vibrational energy dependence, in particular, competition between channels N+ + NO and N-2(+) + O. On the basis of the opposite trends of branching ratios and average releases of kinetic energy of these two channels at levels (1,0,0) and (0,0,1), the dissociation mechanism and energy partition upon dissociation are discussed.