Fluorescence from the A2Σ+state suggests a non-Franck–Condon N2O+•vibrational state population after keV collisional activation with helium

Abstract

A commercial analytical mass spectrometer coupled with a spectrograph and charge-coupled device (CCD) detector was used to obtain the collision-induced emission (CIE) spectra (190–1020 nm) from ion–molecule collisions between N2O+•and He at laboratory frame collision energies of 4–8 keV. The observed emissions were from the A2Σ+ → X2Π+system of N2O+•, excited fragments of the parent molecule, and the target gas. The relative emission intensities of the N2O+•ions and their fragments were independent of the ion translational energy within the 4–8 keV range, confirming the curve-crossing mechanism for translational-to-internal energy transfer in this system. Band emission intensities of [Formula: see text] and [Formula: see text] relative to the [Formula: see text] band within the N2O+•(A → X) system have been measured and compared with reference data. The results indicated that the collisionally excited ion has a decidedly non-Franck–Condon vibrational state distribution.