Ion-ion mutual neutralization of N2+ with F− and other fluorine-containing negative ions

The positive ion-negative ion neutralization reaction of molecular nitrogen ion (N2+) with F− and other negative ions such as SF5− has been studied using the flowing afterglow technique. It has been observed that the product neutral N2 is not only formed in an electronically excited state but is also vibrationally excited. The vibrational population distribution of the N2(B 3Πg) product shows a non-Franck-Condon behavior with a peak at ν′ = 7 which may be attributed to the avoided curve crossing of the potential energy surface of the intermediate binary complex in the charge-separated N2+F− ion pair state with that of the neutral covalent N2(a)-F intermediate hypersurface and the energy degeneracy of N2(a 1Πg, ν′ = 1) and N2(B 3Πg, ν′ = 7) levels.