Correction: A shock tube study of the branching ratios of propene + OH reaction.

Correction for 'A shock tube study of the branching ratios of propene + OH reaction' by Jihad Badra et al., Phys. Chem. Chem. Phys., 2015, 17, 2421-2431.

A shock tube study of the branching ratios of propene + OH reaction.

Absolute rate coefficients for the reaction of the OH radical with propene (C3H6) and five deuterated isotopes, propene-1-D1 (CDHCHCH3), propene-1,1-D2 (CD2CHCH3), propene-1,1,2-D3 (CD2CDCH3), propene-3,3,3-D3 (CH2CHCD3), and propene-D6 (C3D6), were measured behind reflected shock waves over the temperature range of 818-1460 K and pressures near 1 atm. The reaction progress was followed by monitoring the OH radical near 306.7 nm using UV laser absorption. Kinetic isotope effects in the measured rate coefficients are discussed and rationalized for the site-specific H-abstraction by the OH radical. The first experimental measurements for the branching ratio of the title reaction are reported and compared with transition state theory calculations. The allylic H-atom abstraction of propene by OH radicals was found to be the most dominant reaction pathway followed by propen-1-yl and propen-2-yl channels over the entire temperature range of this study. The derived Arrhenius expressions for various site-specific rate coefficients over 818-1442 K are (the subscript in the rate coefficient identifies the position of H or D atom according to the IUPAC nomenclature of alkenes):

Site-specific rate constant measurements for primary and secondary H- and D-abstraction by OH radicals: propane and n-butane.

Site-specific rate constants for hydrogen (H) and deuterium (D) abstraction by hydroxyl (OH) radicals were determined experimentally by monitoring the reaction of OH with two normal and six deuterated alkanes. The studied alkanes include propane (C3H8), propane 2,2 D2 (CH3CD2CH3), propane 1,1,1-3,3,3 D6 (CD3CH2CD3), propane D8 (C3D8), n-butane (n-C4H10), butane 2,2-3,3 D4 (CH3CD2CD2CH3), butane 1,1,1-4,4,4 D6 (CD3CH2CH2CD3), and butane D10 (C4D10). Rate constant measurements were carried out over 840-1470 K and 1.2-2.1 atm using a shock tube and OH laser absorption. Previous low-temperature data were combined with the current high-temperature measurements to generate three-parameter fits which were then used to determine the site-specific rate constants. Two primary (P1,H and P1,D) and four secondary (S00,H, S00,D, S01,H, and S01,D) H- and D-abstraction rate constants, in which the subscripts refer to the number of C atoms connected to the next-nearest-neighbor C atom, are obtained. The modified Arrhenius expressions for the six site-specific abstractions by OH radicals are P1,H = 1.90 × 10(-18)T(2.00) exp(-340.87 K/T) cm(3) molecule(-1) s(-1) (210-1294 K); P1,D = 2.72 × 10(-17) T(1.60) exp(-895.57 K/T) cm(3) molecule(-1) s(-1) (295-1317 K); S00,H = 4.40 × 10(-18) T(1.93) exp(121.50 K/T) cm(3) molecule(-1) s(-1) (210-1294 K); S00,D = 1.45 × 10(-20) T(2.69) exp(282.36 K/T) cm(3) molecule(-1) s(-1) (295-1341 K); S01,H = 4.65 × 10(-17) T(1.60) exp(-236.98 K/T) cm(3) molecule(-1) s(-1) (235-1407 K); S01,D = 1.26 × 10(-18) T(2.07) exp(-77.00 K/T) cm(3) molecule(-1) s(-1) (294-1412 K).

Reaction rate constants of H-abstraction by OH from large ketones: measurements and site-specific rate rules.

Reaction rate constants of the reaction of four large ketones with hydroxyl (OH) are investigated behind reflected shock waves using OH laser absorption. The studied ketones are isomers of hexanone and include 2-hexanone, 3-hexanone, 3-methyl-2-pentanone, and 4-methl-2-pentanone. Rate constants are measured under pseudo-first-order kinetics at temperatures ranging from 866 K to 1375 K and pressures near 1.5 atm. The reported high-temperature rate constant measurements are the first direct measurements for these ketones under combustion-relevant conditions. The effects of the position of the carbonyl group (C=O) and methyl (CH3) branching on the overall rate constant with OH are examined. Using previously published data, rate constant expressions covering, low-to-high temperatures, are developed for acetone, 2-butanone, 3-pentanone, and the hexanone isomers studied here. These Arrhenius expressions are used to devise rate rules for H-abstraction from various sites. Specifically, the current scheme is applied with good success to H-abstraction by OH from a series of n-ketones. Finally, general expressions for primary and secondary site-specific H-abstraction by OH from ketones are proposed as follows (the subscript numbers indicate the number of carbon atoms bonded to the next-nearest-neighbor carbon atom, the subscript CO indicates that the abstraction is from a site next to the carbonyl group (C=O), and the prime is used to differentiate different neighboring environments of a methylene group):