Kinetic Study on\nthe H‑Abstraction Reactions\nfrom 1‑Nitropropane by H and OH Radicals

To improve the comprehension of the combustion kinetics\nof 1-nitropropane\n(1-NP), the H-abstraction reactions from 1-NP by H and OH radicals\nare theoretically explored using the canonical variational transition-state\ntheory combined with the multistructural torsional anharmonicity and\nsmall-curvature tunneling corrections (MS-CVT/SCT). The M08-HX/cc-pVTZ\nmethod is adopted for geometry optimizations and frequency calculations\ndue to its effective performance in describing the current reaction\nsystems with an average mean unsigned deviation of 0.95 kcal mol<sup>–1</sup> against the benchmark by the high-level DLPNO–CCSD(T)/CBS(T-Q)\nmethod. The rate constants for the investigated reactions are calculated\nusing the MS-CVT/SCT method at 200–2000 K, and a good agreement\nis achieved by comparing our calculations with the available literature\ndata. The rate constant calculations show that the multistructural\ntorsional anharmonicity, variational effect, and tunneling effect\nhave different influences on the H-abstraction reactions 1-NP + H/OH,\nand the reaction channel at the C<sub>β</sub> position is the\nmost important above the room temperature. With our calculations,\na literature combustion kinetic model of 1-NP is revised, and the\nnew model demonstrates improved performance across most conditions.\nSensitivity analysis demonstrates that the H-abstraction reaction\nchannel, 1-NP + OH = CH<sub>3</sub>CHCH<sub>2</sub>NO<sub>2</sub> +\nH<sub>2</sub>O, alters the combustion kinetics of 1-NP and plays an\nimportant role in controlling its ignition process.