Probing the new bond in the vibrationally controlled bimolecular reaction of O with HOD(4νOH)

Abstract

Previous studies of the hydrogen abstraction from vibrationally excited H2O and HCN by various atoms have probed the vibrational and rotational energy of the product containing the surviving bond to assess the energy disposal and determine the mechanism of the reaction. Estimating the relative translational energy of the products from the Doppler broadening of the probe transitions has allowed the inference of the internal energy of the unobserved product containing the new bond using conservation of energy. The experiments presented here directly measure the vibrational and rotational energy of both the OH product (containing the new bond) and OD product (containing the old bond) from the reaction of O atoms with HOD having four quanta of O–H stretching excitation (4νOH). All of the OH products are vibrationally excited, being formed almost exclusively in ν=2. Nearly all of the OD products are vibrationally unexcited, with 93% in v=0 and only 7% in v=1. The results are consistent with a spectator picture of the reaction in which the new bond receives most of the available energy.