The Cr - D2 cation complex: Accurate experimental dissociation energy, intermolecular bond length, and vibrational parameters

Abstract

The infrared spectrum of the T-shaped 52Cr+ - D 2 complex is measured over the 2742-2820 cm-1 range by detecting Cr+ photofragments. The main band, due to the D-D stretch excitation, is shifted at 215 cm-1 to lower energy from the Q 10 transition of the free D2 molecule and displays clearly resolved rovibrational transitions. Observation of a photodissociation onset for the N′ =8 rotational level is used to infer that the dissociation energy of Cr+ - D2, with respect to ground-state Cr+ and D2 fragments, lies between 2839.7 and 2856.9 cm-1. Perturbations to the upper state levels are presumed to arise from interactions with quasibound combination levels involving the intermolecular stretch a..