Rate Constants for the Reaction of Cl with a Series of C<sub>4</sub> to C<sub>6</sub> Ketones Using the Relative Rate Method

Ew, Kaiser; Tj, Wallington

doi:10.1021/jp075088i

Cited by 10 publications

(13 citation statements)

References 8 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Included in Figure is the value reported for this rate constant at 297 K in ref (8.3 × 10 −11 cm 3 molecule −1 s −1 ) using propane as the reference species (diamond), which agrees well with the current data using ethane as the reference. Data from a recent determination of the temperature dependence of k 1 are also presented in Figure .…”

Section: Resultssupporting

confidence: 84%

See 1 more Smart Citation

Products and Mechanism of the Reaction of Chlorine Atoms with 3-Pentanone in 700−950 Torr of N₂/O₂ Diluent at 297−515 K

2009

Self Cite

View full text Add to dashboard Cite

The products, kinetics, and mechanism of the reaction Cl + 3-pentanone have been measured by UV irradiation of Cl(2)/3-pentanone/N(2) (O(2)) mixtures using primarily GC analysis with selected cross checks by FTIR. In the absence of O(2), the products are 1- and 2-chloro-3-pentanone with yields of 21 and 78%, respectively. As the temperature is increased, the yield of 1-chloro-3-pentanone increases modestly relative to the 2-chloro-3-pentanone yield. On the basis of this increase, the activation energy for hydrogen abstraction at the 1 position is determined to be 500 (+/-500) cal mole(-1) relative to abstraction at the 2 position. In the presence of 500 ppm of O(2) with 900-1000 ppm of Cl(2) at 297 K, the yield of 2-chloro-3-pentanone decreases dramatically from 78 to 2.5%, while the 1-chloro-3-pentanone decreases only modestly from 21 to 17%. The observed oxygenated species are acetaldehyde (59%), 2,3-pentanedione (9%), and propionyl chloride (56%). Increasing the temperature to 420 K (O(2) = 500 ppm) suppresses these oxygenated products, and 2-chloro-3-pentanone again becomes the primary product, indicating that the O(2) addition reaction to the 2-pentanonyl radical has become reversible. At 500 K and 10 000 ppm O(2), a new product channel opens which forms a small yield ( approximately 4%) of ethylvinylketone. Computer modeling of the product yields has been performed to gain an understanding of the overall reaction mechanism in the presence and absence of O(2). The reaction of chlorine atoms with 3-pentanone proceeds with a rate constant of 8.1 (+/-0.8) x 10(-11) cm(3) molecule(-1) s(-1) independent of temperature over the range of 297-490 K (E(a) = 0 +/- 200 cal mole(-1)). Rate constant ratios of k(C(2)H(5)C(O)CHCH(3) + Cl(2))/k(C(2)H(5)C(O)CHCH(3) + O(2)) = 0.0185 +/- 0.0037 and k(C(2)H(5)C(O)CH(2)CH(2) + Cl(2))/k(C(2)H(5)CH(2)C(O)CH(2)CH(2) + O(2)) = 2.7 +/- 0.4 were determined at 297 K in 800-950 Torr of N(2)/O(2) diluent. In 800-950 Torr of N(2)/O(2) diluent, the major fate of the alkoxy radical CH(3)CH(O)C(O)C(2)H(5) is decomposition to give C(2)H(5)C(O) radicals and CH(3)CHO. These results show that the chemical mechanisms of the 3-pentanone reactions are very similar to those observed for butanone. In addition, the rate constants of the reactions of chlorine atoms with 1-chloro-3-pentanone [3 (+/-0.6) x 10(-11) over the range of 297-460 K], 2,3-pentanedione [1.4 (+/-0.3) x 10(-11) at 297 K], and ethylvinylketone [1.9 (+/-0.4) x 10(-10) over the range of 297-400 K, decreasing rapidly above 400 K] were measured at ambient pressure.

show abstract

Section: Resultssupporting

confidence: 84%

“…In addition, an irradiation experiment was performed in the absence of Cl 2 to verify that direct photolysis of 3-pentanone does not occur. No photolysis was observed in this experiment (see ref 6).…”

Section: Methodsmentioning

confidence: 65%

Products and Mechanism of the Reaction of Chlorine Atoms with 3-Pentanone in 700−950 Torr of N₂/O₂ Diluent at 297−515 K

2009

Self Cite

View full text Add to dashboard Cite

show abstract

“…Although this value of F (C(O)) has a large uncertainty (with an upper limit of F (C(O)) < 0.3), it is clear that the CO group in the ketones is highly deactivating and that H‐atom abstraction from the neighboring CH 2  groups in the cycloketones studied is of minor importance. The use of F (C(O)) = 0.04 combined with the other group rate constants and substituent factors given above leads to predicted rate constants which agree with the recommended room temperature rate constants of Calvert et al 15 (and those of Kaiser and Wallington 28), for acetone, 2‐butanone, 2‐pentanone, 3‐pentanone, 3‐methyl‐2‐butanone, 2‐hexanone, 3‐hexanone, 4‐methyl‐2‐pentanone, and 5‐methyl‐2‐hexanone to within a factor of 1.3. A value of F (C(O)) = 0.10 also leads to good agreement with the recommendations for these acyclic ketones, other than for acetone where the rate constant is overpredicted by a factor of 3.…”

Section: Discussionsupporting

confidence: 73%

“…A value of F (C(O)) = 0.10 also leads to good agreement with the recommendations for these acyclic ketones, other than for acetone where the rate constant is overpredicted by a factor of 3. In fact, a value of F (C(O)) = 0.10 gives a better fit to the recommended rate constants of Calvert et al 15, and those measured by Kaiser and Wallington 28, for 2‐butanone, 2‐pentanone, 3‐pentanone, 3‐methyl‐2‐butanone, 2‐hexanone and 3‐hexanone, ketones with a more extensive and reliable database than 4‐methyl‐2‐pentanone and 5‐methyl‐2‐hexanone, than does F (C(O)) = 0.04. A value of F (C(O)) = 0.10 also results in good agreement with the rate constants plotted in Fig.…”

Section: Discussionmentioning

confidence: 71%

Rate constants for the reactions of Cl atoms with a series of C₆–C₁₀ cycloalkanes and cycloketones at 297 ± 2 K

Aschmann

Atkinson

2012

Int J of Chemical Kinetics

View full text Add to dashboard Cite

Rate constants for the reactions of Cl atoms with cycloheptane, cyclooctane, cyclodecane, cyclohexanone, cycloheptanone, cyclooctanone, and cyclodecanone have been measured at 297 ± 2 K and atmospheric pressure of air using a relative rate method. n-Butane, with a rate constant of 2.05 × 10 −10 cm 3 molecule −1 s −1 , was used as the reference compound, and the rate constants obtained (in units of 10 −10 cm 3 molecule −1 s −1 ) were cycloheptane, 4.22 ± 0.15; cyclooctane, 4.57 ± 0.15; cyclodecane, 5.13 ± 0.15; cyclohexanone, 1.79 ± 0.06; cycloheptanone, 2.46 ± 0.07; cyclooctanone, 2.97 ± 0.09; and cyclodecanone, 3.65 ± 0.15, where the indicated errors are two least-squares standard deviations and do not include uncertainties in the rate constant for the reference compound n-butane. Room temperature rate constants for the C 5 -C 10 cycloketones indicate that the CH 2 groups adjacent to the carbonyl group are almost totally deactivated toward H-atom abstraction by Cl atoms, and this also applies to acyclic ketones. A previous structure-reactivity relationship for Cl + alkanes has been extended to include acyclic and cyclic ketones.

show abstract

“…Reactions of Cl atoms with many volatile organic compounds (VOCs) proceed with high rate coefficients 9 and, therefore, may play an important role in the atmospheric chemistry of remote marine boundary layer 8 as well as the polluted urban areas, with significant anthropogenic emission of Cl 2 10. Hence, measurement of rate coefficients of reactions of Cl atoms with different VOCs has become important 4, and the same has been reported for a large number of saturated and unsaturated organic molecules with different substitutions 11–15. In the case of alkenes, the rate coefficients of reactions of Cl atoms have been measured by different groups 11,16.…”

Section: Introductionmentioning

confidence: 99%

Rate coefficients and products for gas‐phase reactions of chlorine atoms with cyclic unsaturated hydrocarbons at 298 K

Sharma

Pushpa

Dhanya

et al. 2009

Int J of Chemical Kinetics

View full text Add to dashboard Cite

Rate coefficients for the reaction of Cl atoms with cycloalkenes have been determined using the relative rate method, at 298 K and atmospheric pressure of N 2 . Reference molecule was n-hexane, and the concentrations of the organics were followed by gas chromatographic analysis. Cl atoms were prepared by photolysis of trichloroacetyl chloride at 254 nm. The relative rates of reactions of Cl atoms with cycloalkenes, with respect to n-hexane, are measured as 1.12 ± 0.38, 1.31 ± 0.14, and 1.69 ± 0.18 for cyclopentene, cyclohexene, and cycloheptene, respectively. Considering the absolute value of the rate coefficient of the reaction of Cl atom with n-hexane as 3.03 ± 0.06 × 10 −10 cm 3 molecule −1 s −1 , the rate coefficient values for cyclopentene, cyclohexene, and cycloheptene are calculated to be (3.39 ± 1.08) × 10 −10 , (3.97 ± 0.43) × 10 −10 , and (5.12 ± 0.55) × 10 −10 cm 3 molecule −1 s −1 , respectively. The experiments for each molecule were repeated six to eight times, and the slopes and the rate coefficients given above are the average values of these measurements, and the quoted error includes 2σ as well as all other uncertainties in the measurement and calculations. The rate coefficient increases linearly with the number of carbon atoms, with an increment per additional CH 2 group being (8.7 ± 1.6) × 10 −12 cm 3 molecule −1 s −1 . Chloroketones and chloroalcohols, along with unsaturated ketones and alcohols, were found to be the major products of Cl-atom-initiated oxidation of cycloalkenes in the presence of air. The atmospheric implications of these results are discussed, along with a comparison with the reported structure activity relationships.

show abstract

Rate Constants for the Reaction of Cl with a Series of C₄ to C₆ Ketones Using the Relative Rate Method

Cited by 10 publications

References 8 publications

Products and Mechanism of the Reaction of Chlorine Atoms with 3-Pentanone in 700−950 Torr of N₂/O₂ Diluent at 297−515 K

Products and Mechanism of the Reaction of Chlorine Atoms with 3-Pentanone in 700−950 Torr of N₂/O₂ Diluent at 297−515 K

Rate constants for the reactions of Cl atoms with a series of C₆–C₁₀ cycloalkanes and cycloketones at 297 ± 2 K

Rate coefficients and products for gas‐phase reactions of chlorine atoms with cyclic unsaturated hydrocarbons at 298 K

Contact Info

Product

Resources

About

Rate Constants for the Reaction of Cl with a Series of C4 to C6 Ketones Using the Relative Rate Method

Cited by 10 publications

References 8 publications

Products and Mechanism of the Reaction of Chlorine Atoms with 3-Pentanone in 700−950 Torr of N2/O2 Diluent at 297−515 K

Products and Mechanism of the Reaction of Chlorine Atoms with 3-Pentanone in 700−950 Torr of N2/O2 Diluent at 297−515 K

Rate constants for the reactions of Cl atoms with a series of C6–C10 cycloalkanes and cycloketones at 297 ± 2 K

Rate coefficients and products for gas‐phase reactions of chlorine atoms with cyclic unsaturated hydrocarbons at 298 K

Contact Info

Product

Resources

About

Rate Constants for the Reaction of Cl with a Series of C₄ to C₆ Ketones Using the Relative Rate Method

Products and Mechanism of the Reaction of Chlorine Atoms with 3-Pentanone in 700−950 Torr of N₂/O₂ Diluent at 297−515 K

Products and Mechanism of the Reaction of Chlorine Atoms with 3-Pentanone in 700−950 Torr of N₂/O₂ Diluent at 297−515 K

Rate constants for the reactions of Cl atoms with a series of C₆–C₁₀ cycloalkanes and cycloketones at 297 ± 2 K