Thermodynamical analysis of the atmospheric fate of the CH₃SCH₂O₂ radical

Abstract

The thermodynamic properties of nine possible reactions for the atmospheric fate of the CH₃SCH₂O₂ radical are analysed in this work. The reactant species considered were NO, NO₂, HO₂, CH₃O₂, CH₃S, CH₃SO, CH₃SO₂, O and O₂. The calculations were performed at the UCCSD(T)/cc-pVTZ//MP2/6-31G(d) level of theory. Reactions of the CH₃SCH₂O₂ radical with NO, NO₂, HO₂, CH₃S, CH₃SO, CH₃SO₂ and O are exothermic and spontaneous. In the reaction with NO₂, the equilibrium will be highly dislocated towards the reactants. The reaction with CH₃O₂ radical is endothermic by a small quantity, but spontaneous. The estimated rate constant indicates that it will not be important. Reaction with O₂ leading to the CH₃SCH₂O and O₃ products is thermodynamically unfavourable, having a positive reaction enthalpy. The thermodynamical features of the reactions with O and HO₂ radicals indicate that these reactions should be important in this process, and kinetic studies of these reactions are strongly suggested. The heats of formation of the CH₃O₂, CH₃SO, CH₃SO₂, CH₃SO₃, CH₃SCH₂O, CH₃SCH₂O₂H, CH₃SCH₂O₂NO, CH₃SCH₂O₂NO₂, CH₃SCH₂O₃ and CH₃SCH₂O₄ species were determined.

References

1. J. E. Lovelock, R. J. Maggs and R. A. Rasmussen, Nature, 1972, 237, 452.
2. E. S. Saltzman and W. J. Cooper, in Biogenic Sulfur in the Environment, American Chemical Society, Washington, DC 1989.
3. A. J. Hynes, P. H. Wine and D. H. Semmes, J. Phys. Chem., 1986, 90, 4148.
4. N. I. Butkovskaya and G. LeBras, J. Phys. Chem., 1994, 98, 2582.
5. S. M. Resende and W. B. De Almeida, J. Phys. Chem. A, 1997, 101, 9738.
6. T. J. Wallington, T. Ellermann and O. J. Nielsen, J. Phys. Chem., 1993, 97, 8442.
7. S. M. Resende and W. B. De Almeida, J. Phys. Chem. A, in the press.
8. F. Yin, D. Grosjean and J. Seinfeld, Atmos. Chem., 1990, 11, 309; F. Yin, D. Grosjean and J. Seinfeld, Atmos. Chem., 1990, 11, 365.
9. N. R. Jensen, J. Hjorth, C. Lohse, H. Skov and G. Restelli, J. Atmos. Chem., 1992, 14, 95.
10. S. Sorensen, H. Falbe-Hansen, M. Mangoni, J. Hjorth and N. R. Jensen, J. Atmos. Chem., 1996, 24, 299.
11. A. Turnipseed, S. B. Barone and A. R. Ravishankara, J. Phys. Chem., 1996, 100, 14703.
12. S. P. Urbanski, R. E. Stickel, Z. Zhao and P. H. Wine, J. Chem. Soc., Faraday Trans., 1997, 93, 2813.
13. R. E. Stickel, Z. Zhao and P. H. Wine, Chem. Phys. Lett., 1993, 212, 312.
14. N. R. Jensen, J. Hjorth, C. Lohse., H. Skov and G. Restelli, Atmos. Environ., 1991, 25A, 1897.
15. O. J. Nielsen, J. Sehested and T. J. Wallington, Chem. Phys. Lett., 1995, 236, 385.
16. U. B. Pavanaja, H. P. Upadhyaya, A. V. Sapre, K. V. S. Rama Rao and J. P. Mittal, J. Chem. Soc., Fadaray Trans., 1991, 90, 825.
17. R. J. Cvetanovic, D. L. Singleton and R. S. Irwin, J. Am. Chem. Soc., 1981, 103, 3530.
18. A. A. Turnipseed, S. B. Barone and A. R. Ravishankara, J. Phys. Chem., 1992, 96, 7502.
19. G. S. Tyndall and A. R. Ravishankara, J. Phys. Chem., 1989, 93, 2426.
20. J. Baker and J. M. Dyke, Chem. Phys. Lett, 1993, 213, 257.
21. M. L. McKee, Chem. Phys. Lett., 1994, 231, 257.
22. D. W. Kuhns, T. B. Tran., S. A. Shaffer and F. Turecek, J. Phys. Chem., 1994, 98, 4845.
23. Gaussian 94, Revision D.4, M. J. Frisch, G. W. Trucks, H. B. Schlegel, P. M. W. Gill, B. G. Johnson, M. A. Robb, J. R. Cheeseman, T. Keith, G. A. Petersson, J. A. Montgomery, K. Raghavachari, M. A. Al-Laham, V. G. Zakrzewski, J. V. Ortiz, J. B. Foresman, J. Cioslowski, B. B. Stefanov, A. Nanayakkara, M. Challacombe, C. Y. Peng, P. Y. Ayala, W. Chen, M. W. Wong, J. L. Andres, E. S. Replogle, R. Gomperts, R. L. Martin, D. J. Fox, J. S. Binkley, D. J. Defrees, J. Baker, J. P. Stewart, M. Head-Gordon, C. Gonzalez and J. A. Pople, Gaussian, Inc., Pittsburgh PA, 1995.
24. R. H. Nobes, W. J. Bouma and L. Radom, Chem. Phys. Lett., 1982, 89, 497.
25. L. A. Curtiss, K. Raghavachari and J. A. Pople, J. Chem. Phys., 1993, 98, 1293.
26. P. O. Lowdin, Phys. Rev., 1955, 97, 1509.
27. M. W. Chase, Jr., C. A. Davies, J. R. Downey, Jr., D. J. Frurip, R. A. McDonald and A. N. Syverud, JANAF Thermochemical Tables, 3rd edn., J. Phys. Chem. Ref. Data, 1985, 14, Suppl. 1.
28. A. J. Hills and C. J. Howard, J. Chem. Phys., 1984, 81, 4458.
29. W. Tsang, in Energetics of Organic Free Radicals, ed. J. A. Martinho Simoes, A. Greenberg and J. F. Liebman, Blackie Academic and Professional, London, 1996, pp 25–58.
30. L. S. G. Shum and S. W. Benson, Int. J. Chem. Kinet., 1983, 15, 433.
31. W. Hung, M. Shen, Y. Lee, N. Wang and B. Cheng, J. Chem. Phys., 1996, 105, 7402.
32. I. R. Slagle and D. Gutman, J. Phys. Chem., 1985, 107, 5342.
33. G. S. Tyndall and A. R. Ravishankara, J. Phys. Chem., 1989, 93, 4707.
34. S. W. Benson, Chem. Rev., 1978, 78, 23.
35. F. Dominé, T. P. Murrels and C. J. Howard, J. Phys. Chem., 1994, 94, 5839.
36. G. P. Ayers, J. M. Cainey, H. Granek and C. Leck, J. Atmos. Chem., 1996, 25, 307.
37. S. Koga and H. Tanaka, J. Atmos. Chem., 1996, 23, 163.
38. H. Okabe, Photochemistry of small molecules, Wiley, New York, 1978.