Angular momenta correlation in kinematically constrained reactions. II. Application to the B + OH → BO + H system

Abstract

Extensive quasi-classical trajectory (QCT) calculations have been carried out to study the disposal of both rotational and orbital angular momentum in the B + OH → BO + H reaction. The potential energy surface (PES) of this reaction shows two minima associated with the HOB and HBO configurations. In addition, two distinct PESs were used each having a different geometrical structure of the HOB intermediate: bent for surface 1 and linear for surface 2. For the title reaction the product angular momentum disposal shows significant deviations from the kinematic limit expected for a heavy + heavy-light (HH'L) reaction. The analysis of the product angular momenta distribution clearly indicates a correlation with the topology of the PES used. It was found that while the insertion mechanism associated with PES1 (HOB bent intermediate) favours a significant disposal into product rotational and orbital momenta, little disposal into both momenta is obtained for reactive trajectories occurring through the collinear HOB intermediate of PES2, for which BO is highly stretched. A simple modification of the conventional kinematic expressions, aimed at incorporating the effect of the dynamics into the angular momenta transfer, is proposed and tested. Modified expressions give results strongly consistent with those obtained from QCT calculations.