Theoretical study on hydrogen abstraction reactions from cyclopentanol by hydroxyl radical

Cyclopentanol is a novel biofuel with high resistance to auto-ignition, which can be used as a promising additive to gasoline fuel. It is of great importance to gain a comprehensive understanding on the oxidation chemistry of cyclopentanol. The reaction of cyclopentanol with hydroxyl radical plays an important role in both combustion and atmospheric chemistry. In this study, we calculate the rate constants of cyclopentanol reaction with hydroxyl radical over a wide temperature range of 200-2500 K, using multistructural canonical variational transition state theory. The effects of variational, quantum tunneling and multistructural torsional anharmonicity were analyzed. The results show that the variational and multistructural torsional anharmonicity effects play a key role, while the quantum tunneling effect is nearly negligible for the studied reaction system. Moreover, the rate constants of reactions with submerged forward barrier heights show a non-monotonic behavior, while a positive temperature dependence is found for the rate constants of reactions with positive forward barrier heights. Our calculated total rate constants are in good agreement with those estimated in the literature (Cai et al., CNF, 2019), however, significant discrepancies are observed in the branching ratios of reaction channels. The rate constants reported in this study are expected to be more accurate and will benefit the understanding on the oxidation chemistry of cyclopentanol.

Automated summary

This study calculated the rate constants of the reaction between cyclopentanol and hydroxyl radical using multistructural canonical variational transition state theory. The results highlighted the importance of variational and multistructural torsional anharmonicity effects, with quantum tunneling effect being negligible. While the total rate constants were in good agreement with literature estimates, significant discrepancies were observed in the branching ratios of reaction channels.