table 1: high temperature rate data for oh + neo...
TRANSCRIPT
Site-Specific Reaction Rate Constant Measurements for Various Secondary and Tertiary H-Abstraction by
OH Radicals
Jihad Badra, Aamir Farooq*
Supplementary Material: Tables S1-S3, Figures S1-S5
Table S1: Sub-mechanism for 2,2-dimethyl-pentane.
ReactionPre-exponential Factor (A) (cm,
mol, s)
Temperature exponent
(B)
Activation energy
(cal/mol)
c7h16-2-2 + oh c7h15-2-2a + h2o 1.578E+10 0.97 1590c7h16-2-2 + oh c7h15-2-2b + h2o 4.68E+07 1.61 -35c7h16-2-2 + oh c7h15-2-2c + h2o 4.68E+07 1.61 -35c7h16-2-2 + oh c7h15-2-2d + h2o 5.28E+09 0.97 1590c7h15-2-2a ic4h8 + nc3h7 3.68E+15 -0.56 31359c7h15-2-2a ch3 + dc6h12 9.55E+14 -0.59 30592c7h15-2-2b ch3 + cc6h12 5.31E+13 0.11 30542c7h15-2-2c c3h6 + ic4h9 2.64E+15 -0.55 31136c7h15-2-2d c2h4 + neoc5h11 2.64E+15 -0.55 31136neoc5h11 ic4h8 + ch3 8.466E+17 -1.111 32930
1
a
b
cd
a
a
Table S2: Sub-mechanism for 2,4-dimethyl-pentane.
ReactionPre-exponential Factor (A) (cm,
mol, s)
Temperature exponent (B)
Activation energy
(cal/mol)
c7h16-2-4 + oh c7h15-2-4a + h2o 2.112E+10 0.97 1590c7h16-2-4 + oh c7h15-2-4b + h2o 1.146E+11 0.51 63c7h16-2-4 + oh c7h15-2-4c + h2o 4.68E+7 1.61 -35c7h15-2-4a ic4h9 + c3h6 3.68E+15 -0.56 31359c7h15-2-4a ch3 + dc6h12 9.55E+14 -0.59 30592c7h15-2-4b c3h7 + ic4h8 1.71E+12 0.31 26610c7h15-2-4c ch3 + cc6h12 9.55E+14 -0.59 30592
2
ab
b
a
a
c
a
Table S3: Sub-mechanism for 2,2,4,4-tetramethyl-pentane.
Reaction
Pre-exponential Factor (A)
(cm, mol, s)
Temperature exponent
(B)
Activation energy
(cal/mol)
c9h20-2-2-4-4 + oh c9h19-2-2-4-4a + h2o 3.168E+10 0.97 1590c9h20-2-2-4-4 + oh c9h19-2-2-4-4b + h2o 4.68E+7 1.61 -35c9h19-2-2-4-4a ic4h8 + neoc5h11 3.68E+15 -0.56 31359neoc5h11 ic4h8 + ch3 8.466E+17 -1.111 32930c9h19-2-2-4-4a ch3 + c8h16-1-2 9.55E+14 -0.59 30592c9h19-2-2-4-4b ch3 + c8h16-2-2 1.90E+15 -0.59 30592
3
a
ba
a
a
aa
Fig. S1. Effect of methyl branching on OH + alkane rate constants at low temperatures
The experimental data of 2-methyl-butane + OH is taken from: Atkinson et al.1, Cox et al.2, Darnall et al.3 and Lloyd et al.4.The experimental data of 2,2-dimethyl-propane + OH is taken from: Greiner5, Darnall et al.3, Paraskevopoulos and Nip6, Atkinson et al.7, Tully et al.8 and Nielsen et al.9.The experimental data of 2,3-dimethyl-butane + OH is taken from: Wilson et al.10, Atkinson et al.7, Darnall et al.3 and Darnall et al.11.The experimental data of 2,2-dimethyl-butane + OH is taken from: Atkinson et al.1 and Harris and Kerr12.
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Fig. S2. Comparison of the rate constants of iso-octane + OH and 2,2,3,3-tetramethyl-
butane + OH.
The experimental data of iso-octane + OH is taken from: the current work, Bott and Cohen13, Greiner5 and Atkinson et al.1.The experimental data of 2,2,3,3-tetramethyl-butane + OH is taken from: Bott and Cohen13, Greiner5, Tully et al.8, Atkinson et al.1 and Baldwin et al.14.
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Fig. S3. Comparison of the rate constants of n-hexane + OH and 3-methyl-pentane + OH.
n-hexane experimental data is taken from: Badra et al.15, Koffend and Cohen16, DeMore and Bayes17, Donahue and Anderson18, Campbell et al.19 and Atkinson et al.1. 3-methyl-pentane experimental data is taken from: Badra et al.15, Lloyd et al.4 and Atkinson et al.1.
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7
P3
P3
P3
S31S10
P1
P2
P2
P2
P2
S22
T100
T100
P3
P3
P3
P2
P2
S32
T100P3
P3
P3
P3
P3
P3
S33
P1
P1
S10
S10
S11
S11
P2
P2
T100
S21
S10
P1
n-Hexane 2-Methyl-Pentane
2-2-4-Trimethyl-Pentane (Iso-Octane)
2,2,4,4-Tetramethyl-Pentane
2,2-Dimethyl-Pentane 2,4-Dimethyl-Pentane
3-Methyl-Pentane
P1
P1
P2
S20 S20
T101
2,2-Dimethyl-Butane
P3
P3
P3S30
P1
Fig. S4. Schematics showing the molecular structures of the eleven studied alkanes with the locations of the site-specific rate constants. Black means it is available from literature,
Red indicates it is derived in the current work.
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2,2-Dimethyl-Butane
P2
P2
P2
P2T200
T200
P2
P2
T100
S21S11’
S11S10
P1
2-Methyl-Heptane
4-Methyl-Heptane
P1P1
P2
S10S10S21 S21
Fig. S5. Arrhenius plot of the secondary site-specific rate constants for a temperature
range of 250 – 1450 K.
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References
1. Atkinson, R.; Carter, W. P. L.; Aschmann, S. M.; Winer, A. M.; Pitts, J. N., Kinetics of the reaction of oh radicals with a series of branched alkanes at 297 ± 2 K. Int. J. Chem. Kinet. 1984, 16, 469-481.2. Cox, R. A.; Derwent, R. G.; Williams, M. R., Atmospheric photooxidation reactions, reactivity, and mechanism for reaction of organic compounds with hydroxyl radicals. Environ. Sci. Technol. 1980, 14, 57-61.3. Darnall, K. R.; Atkinson, R.; Pitts, J. N., Rate constants for the reaction of the hydroxyl radical with selected alkanes at 300 K. J. Phys. Chem. 1978, 82, 1581-1584.4. Lloyd, A. C.; Darnall, K. R.; Winer, A. M.; Pitts, J. J. N., Relative rate constants for reaction of the hydroxyl radical with a series of alkanes, alkenes, and aromatic hydrocarbons. J. Phys. Chem. 1976, 80, 789-794.5. Greiner, N. R., Hydroxyl Radical Kinetics by Kinetic Spectroscopy. VI. Reactions with Alkanes in the Range 300–500°K. J. Chem. Phys. 1970, 53, 1070-1076.6. Paraskevopoulos, G.; Nip, W. S., Rates of OH radical reactions. VII. Reactions of OH and OD radicals with n-C4H10, n-C4D10, H2 and D2, and of OH with neo-C5H12 at 297 K1. Can. J. Chem. 1980, 58, 2146-2149.7. Atkinson, R.; Aschmann, S. M.; Carter, W. P. L.; Winer, A. M.; Pitts, J. N., Kinetics of the reactions of OH radicals with n-alkanes at 299 ± 2 K. Int. J. Chem. Kinet. 1982, 14, 781-788.8. Tully, F. P.; Koszykowski, M. L.; Stephen Binkley, J., Hydrogen-atom abstraction from alkanes by OH. I. Neopentane and neooctane. Proc. Combust. Inst. 1985, 20, 715-721.9. Nielsen, O. J.; O'Farrell, D. J.; Treacy, J. J.; Sidebottom, H. W., Rate constants for the gas-phase reactions of hydroxyl radicals with tetramethyllead and tetraethyllead. Environmental Science & Technology 1991, 25, 1098-1103.10. Wilson, E. W.; Hamilton, W. A.; Kennington, H. R.; Evans, B.; Scott, N. W.; DeMore, W. B., Measurement and Estimation of Rate Constants for the Reactions of Hydroxyl Radical with Several Alkanes and Cycloalkanes. J. Phys. Chem. A 2006 , 110, 3593-3604.11. Darnall, K. R.; Winer, A. M.; Lloyd, A. C.; Pitts Jr, J. N., Relative rate constants for the reaction of OH radicals with selected C6 and C7 alkanes and alkenes at 305 ± 2 K. Chem. Phys. Lett. 1976, 44, 415-418.12. Harris, S. J.; Kerr, J. A., Relative rate measurements of some reactions of hydroxyl radicals with alkanes studied under atmospheric conditions. Int. J. Chem. Kinet. 1988, 20, 939-955.13. Bott, J. F.; Cohen, N., A Shock Tube Study of the Reaction of Methyl Radicals with Hydroxyl Radicals. Int. J. Chem. Kinet. 1991, 23, 1017-1033.14. Baldwin, R. R.; Walker, R. W., Rate constants for hydrogen + oxygen system, and for H atoms and OH radicals + alkanes. J. Chem. Soc., Faraday Trans. 1 1979 , 75, 140-154.15. Badra, J.; Elwardany, A.; Farooq, A., Shock Tube Measurements of the Rate Constants for Seven Large Alkanes + OH. Proc. Combust. Inst. 2014, In Press.16. Koffend, J. B.; Cohen, N., Shock tube study of OH reactions with linear hydrocarbons near 1100 K. Int. J. Chem. Kinet. 1996, 28, 79-87.
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17. DeMore, W. B.; Bayes, K. D., Rate Constants for the Reactions of Hydroxyl Radical with Several Alkanes, Cycloalkanes, and Dimethyl Ether. J. Phys. Chem. A 1999, 103, 2649-2654.18. Donahue, N. M.; Anderson, J. G.; Demerjian, K. L., New Rate Constants for Ten OH Alkane Reactions from 300 to 400 K: An Assessment of Accuracy. J. Phys. Chem. A 1998, 102, 3121-3126.19. Campbell, I. M.; McLaughlin, D. F.; Handy, B. J., Rate constants for reactions of hydroxyl radicals with alcohol vapours at 292 K. Chem. Phys. Lett. 1976, 38, 362-364.
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