Collisional energy transfer, intramolecular vibrational relaxation and unimolecular reactions

Abstract

Experiments on (a) association reactions at very high pressures and (b) vibrational relaxation between species capable of forming a strong chemical bond have confirmed the hypothesis that, for the same chemical system, these two rates are essentially the same, both reflecting the rate of formation of collision complexes. The results of these measurements are reviewed. Subsequently, cases are discussed where the attraction between the collision partners is less strong. In these cases, it seems that the vibrational relaxation rate corresponds to a lower limit for complex formation, as complexes formed in collisions involving a vibrationally excited species may redissociate before intramolecular vibrational relaxation within the complex randomises the energy located in the initially excited vibration. A number of examples, CH+N₂, NO+NO₂, NO+NO, several ion–molecule systems and several involving OH and unsaturated molecules, where this behaviour seems to be occurring are discussed. It is emphasised that, whether or not the limiting, ‘strong attraction’, behaviour is observed will depend on the energy of the colliding species and therefore, in thermal experiments, on temperature. Finally, some consideration is given to the state-to-state aspects of vibrational energy transfer in collisions proceeding via collision complexes.

References

1. E. V. Waage and B. S. Rabinovitch, Chem. Rev., 1969, 70, 377.
2. K. A. Holbrook, M. J. Pilling and S. H. Robertson, Unimolecular Reactions, Wiley, Chichester, 1996.
3. C. B. Moore and I. W. M. Smith, J. Phys. Chem., 1996, 100, 12848.
4. I. W. M. Smith, Kinetics and Dynamics of Elementary Gas Reactions, Butterworths, Oxford, 1980.
5. (a) R. P. Fernando and I. W. M. Smith, Chem. Phys. Lett., 1979, 66, 218; (b) R. P. Fernando and I. W. M. Smith, J. Chem. Soc., Faraday Trans. 2, 1981, 77, 459.
6. M. J. Howard and I. W. M. Smith, Prog. Reac. Kinet., 1983, 12, 55.
7. E. Weitz and G. Flynn, Annu. Rev. Phys. Chem., 1974, 25, 275.
8. (a) C. T. Wickham-Jones, H. T. Williams and C. J. S. M. Simpson, J. Chem. Phys., 1987, 87, 5294; (b) G. J. Wilson, M. L. Turnidge, A. S. Solodukhin and C. J. S. M. Simpson, Chem. Phys. Lett., 1994, 207, 521; (c) J. P. Reid, C. J. S. M. Simpson, H. M. Quiney and J. M. Hutson, J. Chem. Phys., 1995, 103, 2528.
9. I. W. M. Smith, J. Chem. Soc., Faraday Trans., 1991, 87, 2271.
10. I. W. M. Smith, Acc. Chem. Res., 1976, 9, 161.
11. I. W. M. Smith and M. D. Williams, J. Chem. Soc., Faraday Trans. 2, 1985, 81, 1849.
12. (a) I. R. Sims and I. W. M. Smith, J. Chem. Soc. Faraday Trans. 2, 1988, 84, 527; (b) I. R. Sims and I. W. M. Smith, J. Chem. Soc., Faraday Trans., 1993, 89, 1.
13. R. Forster, M. Frost, D. Fulle, H. F. Hamann, H. Hippler, A. Schlepegrell and J. Troe, J. Chem. Phys., 1995, 103, 2949.
14. D. Fulle and H. Hippler, J. Chem. Phys., 1996, 105, 5423.
15. D. Fulle and H. Hippler, J. Chem. Phys., 1997, 106, 8691.
16. J. A. Dodd, S. M. Singleton, S. M. Miller, P. S. Armstrong and W. A. M. Blumberg, Chem. Phys. Lett., 1996, 260, 103.
17. (a) R. Atkinson, D. L. Baulch, R. A. Cox, R. F. Hampson, J. A. Kerr, M. J. Rossi and J. Troe, J. Phys. Chem Ref. Data, 1997, 26, 521; (b) W. B. Demore, S. P. Sander, D. M. Golden, R. F. Hampson, M. J. Kurylo, C. J. Howard, A. R. Ravishankara, C. E. Kolb and M. J. Molina, Chemical Kinetics and Photochemical Data for Use in Stratospheric Modeling Evaluation Number 11, NASA JPL-Publication 94-26, 1994.
18. H. Hippler, H. Stark and J. Troe, J. Chem. Phys., 1997, in press.
19. S. M. Anderson, F. S. Klein and F. Kaufman, J. Chem. Phys., 1985, 83, 1648.
20. L. B. Herbert, I. R. Sims, I. W. M. Smith, D. W. A. Stewart, A. C. Symonds, A. Canosa and B. R. Rowe, J. Phys. Chem., 1996, 100, 14928.
21. R. A. Brownsword, A. Canosa, B. R. Rowe, I. R. Sims, I. W. M. Smith, D. W. A. Stewart, A. C. Symonds and D. Travers, J. Chem. Phys., 1997, 106, 7662.
22. R. A. Brownsword, L. B. Herbert, I. W. M. Smith and D. W. A. Stewart, J. Chem. Soc., Faraday Trans., 1996, 92, 1087.
23. I. R. Sims, J.-L. Queffelec, A. Defrance, C. Rebrion-Rowe, D. Travers, P. Bocherel, B. R. Rowe and I. W. M. Smith, J. Chem. Phys., 1994, 100, 4229.
24. I. R. Sims and I. W. M. Smith, Annu. Rev. Phys. Chem., 1995, 46, 109.
25. (a) M. Aoyagi, R. Shepard, A. F. Wagner, T. H. Dunning, Jr. and F. B. Brown, J. Phys. Chem., 1990, 94, 3236; (b) M. Aoyagi, R. Shepard and A. F. Wagner, Int. J. Supercomputer Appl., 1991, 5, 72.
26. J. M. L. Martin and P. R. Taylor, Chem. Phys. Lett., 1993, 209, 143.
27. Z. S. Huang, K. W. Jucks and R. E. Miller, J. Chem. Phys., 1986, 85, 6905.
28. R. E. Miller, Science, 1988, 240, 447.
29. D. C. Dayton, P. A. Block and R. E. Miller, J. Phys. Chem., 1991, 95, 2881.
30. J. R. Hetzler, M. P. Casassa and D. S. King, J. Phys. Chem., 1991, 95, 8086.
31. B. Abel, H. H. Hamann and N. Lange, Faraday Discuss., 1995, 102, 147.
32. (a) G. V. Hartland, D. Qin and H. L. Dai, J. Chem. Phys., 1994, 100, 7832; (b) G. V. Hartland, D. Qin and H. L. Dai, J. Chem. Phys., 1995, 102, 8677.
33. J. C. Stephenson, J. Chem. Phys., 1974, 60, 4289.22.
34. (a) I. J. Wysong, Chem. Phys. Lett., 1994, 227, 69; (b) I. J. Wysong, J. Chem. Phys., 1994, 101, 2800.
35. (a) I. W. M. Smith and G. Yarwood, Chem. Phys. Lett., 1986, 130, 24; (b) I. W. M. Smith and G. Yarwood, Faraday Discuss. Chem. Soc., 1987, 84, 205.
36. B. Markwalder, P. Gozel and H. van den Bergh, J. Phys. Chem., 1993, 97, 5260.
37. L. A. Chewter, I. W. M. Smith and G. Yarwood, Mol. Phys., 1988, 63, 843.
38. P. L. James, I. R. Sims and I. W. M. Smith, Chem. Phys. Lett., 1997, in press.
39. E. E. Ferguson, J. Phys. Chem., 1987, 90, 731.
40. I. Dotan, S. E. Barlow and E. E. Ferguson, Chem. Phys. Lett., 1985, 121, 38.
41. A. A. Viggiano, R. A. Morris, F. Dale, J. F. Paulson and E. E. Ferguson, J. Chem. Phys., 1989, 90, 1648.
42. M. Kriegel, R. Richter, P. Tosi, W. Federer, W. Lindinger and E. E. Ferguson, Chem. Phys. Lett., 1986, 124, 583.
43. R. Richter, W. Lindinger and E. E. Ferguson, J. Chem. Phys., 1988, 89, 5962.
44. M. Hawley and M. A. Smith, J. Chem. Phys., 1991, 95, 8662.
45. E. Silvente, R. C. Richter and A. J. Hynes, J. Chem. Soc. Faraday Trans., 1997, 93, 2821.
46. J. Brunning, D. W. Derbyshire, I. W. M. Smith and M. D. Williams, J. Chem. Soc. Faraday Trans. 2, 1988, 84, 105.
47. J. A. Dodd, S. J. Lipson and W. A. M. Blumberg, J. Chem. Phys., 1991, 95, 3572.
48. K. J. Rensberger, J. B. Jeffries and D. R. Crosley, J. Chem. Phys., 1989, 90, 2174.
49. G. A. Raiche, J. B. Jeffries, K. J. Rensberger and D. R. Crosley, J. Chem. Phys., 1990, 92, 7258.
50. B. R. Chalamala and R. A. Copeland, J. Chem. Phys., 1993, 99, 5807.
51. K. Knutsen, M. J. Dyer and R. A. Copeland, J. Chem. Phys., 1996, 104, 5798.
52. W. H. Green and J. K. Hancock, IEEE J. Quantum Electron., 1973, QE-9, 50.
53. (a) J. F. Bott and N. Cohen, J. Chem. Phys., 1973, 58, 4539; (b) F. Bott and N. Cohen, J. Chem. Phys., 1974, 61, 681.
54. S. R. Leone, J. Phys. Chem., Ref. Data, 1982, 11, 953.
55. R. N. Sileo and T. A. Cool, J. Chem. Phys., 1976, 65, 117.
56. D. D. Nelson Jr., A. Schiffman, D. J. Nesbitt, J. J. Orlando and J. B. Burkholder, J. Chem. Phys., 1990, 93, 7003.
57. J. A. Dodd, S. J. Lipson, J. R. Lowell, P. S. Armstrong, W. A. M. Blumberg, R. M. Nadile, S. M. Adler-Golden, W. J. Marinelli, K. W. Holtzclaw and B. D. Green, J. Geophys. Res., 1994, 99, 3559.
58. A. B. Meinel, Astrophys. J., 1950, 111, 555.
59. (a) D. V. Shalashilin, S. Ya. Umanskii and Y. M. Gershenzon, Chem. Phys., 1992, 68, 315; (b) D. V. Shalashilin, A. V. Michtchenko, S. Ya. Umanskii and Y. M. Gershenzon, J. Phys. Chem., 1995, 99, 11627.