Kinetics of abstraction reactions of tert-butoxyl radicals with cyclohexane and methyl-substituted cyclohexanes in the gas phase

Abstract

The reactions of tert-butoxyl radicals, generated by the pyrolysis of di-tert-butyl peroxide with cyclohexane and a number of methyl-substituted cyclohexanes have been studied. The Arrhenius parameters corresponding to overall hydrogen abstraction have been determined in the temperature range 399-434 K based on the values of the Arrhenius parameters for pressure-dependent decomposition of tert-butoxyl radicals obtained by Batt and Robinson (L. Batt and G. N. Robinson, lnt. J. Chern.

Evaluated Site-Specific Rate Constants for Reaction of Isobutane with H and CH3: Shock Tube Experiments Combined with Bayesian Model Optimization

“…CH 3 radicals were created by photolyzing a variety of precursors, including acetone, dimethyldiazene, and dimethylmercury, and typically had a 5–30% correction for the reaction of CH 3 with the precursor. This method of measuring the rate of CH 3 reaction with isobutane relative to reaction was repeated by multiple other groups with temperatures ranging from 384 to 766 K. ,, We assigned a factor of 1.5 uncertainty to all these experiments, including those of Steacie and co-workers, − except for the work of Marshall and Shahkar, for which we assigned an uncertainty of 2 because they did not report exact experimental pressures, which affects calculation of the rate of reaction . Ahonkhai et al also found the total rate constant (673–766 K) but measured it relative to the rate of CH 3 + ethene.…”

“…Comparison of the target experimental values − ,,− , of the total rate constant for CH 3 + isobutane, k 656 + k 657 (a), and the rate constant for primary attack, k 656 (b), to the prior (dashed red line), forced (dotted black line), and posterior model values (dotted gray line).…”

Laser powered homogeneous pyrolysis of ethyne, propyne, and propadiene initiated by methyl radicals: formation and degradation of hydrocarbons at 800–950 K

“…The rate coefficients for the decomposition of ditert-butyl peroxide and of the tert-C 4 H 9 O radicals are taken from the literature. [9][10][11] The relevant reactions of saturated alkanes (C 1 -C 5 ), and of the alkyl radicals (C 1 -C 5 ) as well as the chemistry of the unsaturated hydrocarbons, and especially that of the aromatics were adopted from the detailed work of. 14,15 The kinetic modelling was performed using the CHEM-KIN programs, 16 assuming isothermal and nearly constant pressure conditions.…”

Structure‐dependence in initial decomposition of trans‐1,2‐dimethylcyclohexyl isomers: Kinetic exploration and conformational analysis

“…Combustion chemistry of cycloalkanes has been caught much attention and motivated the ongoing researches because of their importance in real fuels [1][2][3][4][5][6]. For instance, cycloalkanes comprise 30% of conventional diesel [2], 20% of jet fuel [2], and 10%-30% of automotive and aviation gasoline [7].…”

“…These aim to gain insight into their combustion properties and fundamentally uncover the detailed chemical mechanisms, particularly for low temperature oxidation chemistry, to promote stable, efficient, and clean combustion in practical applications [8,9,11,12]. On base of the cornerstone studies for cyclohexane (CH), methylcyclohexane (MCH), and ethylcyclohexane (ECH) [7-9, 11, 13-16], multiple alkyl-substituted cycloalkanes have been further investigated, but the limited kinetic data were provided for several types of reactions, including ring cleavage reactions of 1,2DMCH and 1,3DMCH by Dokjampa et al [17,18] and Do et al [19], isomerization of cis-1,2DMCH by Rosado-Reyes and Tsang [20], and H-abstractions of dimethyl-and trimethylcyclohexanes by Sway [6]. Additionally, some studies tried to keep a foothold on the molecular reactivity for multiple alkyl-substituted cycloalkanes.…”