Detailed kinetic study of hydrogen abstraction reactions of triphenylene, benzo[e]pyrene, dibenzo[fg,op]naphtacene, and coronene by H atoms

Abstract

AbstractThe thermochemical and dynamics of H‐abstraction reactions by H atoms have been investigated for large polycyclic aromatic hydrocarbons (PAHs) including triphenylene, benzo[e]pyrene, dibenzo[fg,op]naphtacene, and coronene using high‐level ab initio methods, UCCSD(T)‐F12. Highly accurate ground‐state potential energy surfaces were obtained and used to compute reliable kinetic data. The structures and vibrational frequencies of all species involved in these reactions have been calculated using the CAM‐B3LYP/6‐311++G(d,p) level of theory. The thermodynamic and kinetic properties have been computed at both used levels of theories. For each type of site, the rate constants were calculated in the 500–2500 K temperature range. The results demonstrate that the overall rate constants of H‐abstraction reactions from PAHs with H atoms are not sensitive to the PAHs and their structures. An overall rate constant expression for these processes regardless of the size and structure of the PAH considered is proposed: k(T) = 5.53 × 107 × T2.19exp(58.09(kJ mol−1)/RT).