Kinetics of the Hydrogen Abstraction PAH + •OH → PAH Radical + H2O Reaction Class: An Application of the Reaction Class Transition State Theory (RC-TST) and Structure-Activity Relationship (SAR).

A reaction class transition state theory (RC-TST) augmented with structure-activity relationship (SAR) methodology is applied to predict high-pressure limit thermal rate constants for hydrogen abstraction by •OH radical from polycyclic aromatic hydrocarbons (PAHs) reaction class in the temperature range of 300-3000 K. The rate constants for the reference reaction of C6H6 + •OH → C6H5 + H2O is calculated by the canonical variational transition state theory (CVT) with small curvature tunneling (SCT). Only the reaction energy is needed to predict RC-TST rates for other processes within the family, the parameters needed were obtained from M06-2X/cc-pVTZ data for a training set of 34 reactions. The systematic error of the resulting RC-TST rates is smaller than 50% in comparison with explicit rate calculations, which facilitates application of the proposed methodology to the automated reaction mechanism generators (ARMGs) schemes.