Photofragment spectroscopy and dissociation dynamics of N2+2: A 1Πu–X 1Σ+g

The 9–0 and 9–1 transitions of the A 1Πu–X 1Σ+g system of N2+2 have been observed by fast ion beam photofragment spectroscopy. Multireference configuration interaction ab initio calculations predict v′=8 to be the highest bound level which seemed to be supported by experimental evidence. The dominant predissociation mechanism for the v′=9 level appears to be through tunneling, unlike the v′=6, 7, and 8 levels, which show an e/f symmetry-dependent electronic predissociation. Calculated tunneling lifetimes from our own modified A 1Πu state potential gives good agreement with the experimental lifetimes. In addition to the 9–1 and 9–0 bands, we have also measured the previously unobserved 7–0 and 8–0 rovibronic transitions thus extending Cosby, Müller, and Helm’s study to the blue [Phys. Rev. A 28, 766 (1983)]. Molecular constants have been determined for the v=0 of the X 1Σ+g state and v=7, 8, and 9 of the A 1Πu state.