Details of exit channel dynamics of the ozonolysis of catechol in condensed phase: Product channels and product energy partitioning

Abstract

Direct dynamics simulations on the ozonolysis reaction of catechol is performed in a vacuum and in an N2 bath to study the various aspects of the exit channel dynamics of the reaction. The simulations were conducted at 20 and 324 kg/m3 densities, with 200 and 293 N2 molecules in the bath, respectively. It is a post-transition state (TS) direct dynamics simulation, where the TS of the catechol+O3 system is taken as the reactant. High combustion temperatures of 800, 1000, and 1500 K are considered for the reactant excitation. In contrast, the bath is taken at 300 K. CO, H2O, CO2, O2, and small carboxylic acid (SCA) are the major channels observed for this reaction. Explicit study of the product channels along with rate constants of all the product channels are obtained. The rate constants are in the order of ns−1. The partitioning of the product's internal energy into its various modes and how the energy transfer occurs in the formation of the products is an exciting aspect of the study. Also reported in this work is the branching ratio of the products and comparison with the experimentally reported data. The energy partitioning study reveals that the dissociation dynamics of the catechol-O3 TS is not statistical. In contrast, the bath dynamics, which correspond to the energy transfer from the TS to the bath, is statistical in nature.