NO3-initiated degradation of 1,2,3-trimethylbenzene in the atmosphere: Mechanisms, kinetics and insights.

In present work, the degradation mechanisms of 1,2,3-trimethylbenzene (1,2,3-TMB) initiated by NO3 radical were researched using quantum chemical method. Results manifest that both addition and abstraction (including H-abstraction and CH3-abstraction) mechanisms could take place, with the addition and H-abstraction mechanism being competitive with each other. Furthermore, the subsequent reactions of the main products of the addition and H-abstraction reaction channels in the atmosphere were also considered, as well. The rate coefficients were computed in the atmosphere through Rice-Ramsperger-Kassel-Marcus theory and transition-state theory. The computed total rate coefficient at 1atm and 296 K is 1.53 × 10-16 cm3 molecule-1 · s-1, which is in accordance with the now available experimental data in the atmosphere. The present investigation could enhance our understanding of the transformation of 1,2,3-TRT in complex atmospheric environments.