2018

A theoretical and shock tube kinetic study on hydrogen abstraction from phenyl formate

​A theoretical and shock tube kinetic study on hydrogen abstraction from phenyl formate

H. Ning, D. Liu, J. Wu, L. Ma, W. Ren, A. Farooq

Physical Chemistry Chemical Physics
H. Ning, D. Liu, J. Wu, L. Ma, W. Ren, A. Farooq
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2018


The hydrogen abstraction reactions of phenyl formate (PF) by different radicals (H/O(3P)/OH/HO2) were theoretically investigated. We calculated the reaction energetics for PF + H/O/OH using the composite method ROCBS-QB3//M06-2X/cc-pVTZ and that for PF + HO2 at the M06-2X/cc-pVTZ level of theory. The high-pressure limit rate constants were calculated using the transition state theory in conjunction with the 1-D hindered rotor approximation and tunneling correction. Three-parameter Arrhenius expressions of rate constants were provided over the temperature range of 500–2000 K. To validate the theoretical calculations, the overall rate constants of PF + OH → Products were measured in shock tube experiments at 968–1128 K and 1.16–1.25 atm using OH laser absorption. The predicted overall rate constants agree well with the shock tube data (within 15%) over the entire experimental conditions. Rate constant analysis indicates that the H-abstraction at the formic acid site dominates the PF consumption, whereas the contribution of H-abstractions at the aromatic ring increases with temperature. Additionally, comparisons of site-specific H-abstractions from PF with methyl formate, ethyl formate, benzene, and toluene were performed to understand the effects of the aromatic ring and side-chain substituent on H-abstraction rate constants.
DOI: 10.1039/C8CP02075B