Intramolecular Processes in Isolated Polyatomic Molecules

  • Martin R. Levy
  • Anita M. Renlund
  • Tom A. Watson
  • Metin S. Mangir
  • Hanna Reisler
  • Curt Wittig
Conference paper


This paper deals with certain rather well known unimolecular processes which occur in isolated polyatomic molecules. These processes are (i) chemical reactions, forming fragments with identifiable internal and translational energy distributions, and (ii) the coupling of vibrational and electronic degrees of freedom, a phenomenon which is responsible for so-called radiationless transitions. The work is mainly experimental, and capitalizes on the fact that infrared lasers can be used to excite the vibrations of polyatomics in the absence of collisions. Thus, parent translational and rotational energies are near ambient, while vibrations can be excited rather easily, allowing us to measure elementary unimolecular processes of these species without interference from collisions. Although molecular excitation cannot be adjusted to yield monoenergetic species of excitation, still the “average excitation level” can be controlled, enabling us to determine effects qualitatively. Above dissociation threshold, the balance between the optical pumping rate and the dissociation rate results in a rather narrow range of energies from which dissociation occurs, and by adjusting the laser intensity the mean unimolecular rate can be controlled.


Rotational Temperature Single Longitudinal Mode Unimolecular Reaction Dissociation Threshold Intramolecular Process 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.


Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.


  1. 1.
    See, for example, R.V. Ambartzumian and V.S. Letokhov, in “Chemical and Biochemical Applications of Lasers, II” (C.B. Moore Ed., Academic Press, N.Y., 1977), and references cited therein.Google Scholar
  2. 2.
    H. Reisler, M.S. Mangir, and C. Wittig, unpublished.Google Scholar
  3. 3.
    H. Reisler and C. Wittig, Adv. Chem. Phys., in press.Google Scholar
  4. 4.
    M.H. Yu, H. Reisler, M. Mangir, and C. Wittig, Chem. Phys. Lett. 62, 439 (1979).ADSCrossRefGoogle Scholar
  5. 5.
    M.H. Yu, M.R. Levy, and C. Wittig, J. Chem. Phys. 72, 3789 (1980).ADSCrossRefGoogle Scholar
  6. 6.
    Y. Haas and G. Yahav, Chem. Phys. Lett. 48, 63 (1977).ADSCrossRefGoogle Scholar
  7. 7.
    G. Yahav and Y. Haas, Chem. Phys. 31, 41 (1978).ADSCrossRefGoogle Scholar
  8. 8.
    J.W. Hudgens, J.L. Durant Jr., D.J. Bogan, and R.A. Coveleskie, a) Bull. Am. Phys. Soc. 24, 638 (1979). b) J. Chem. Phys. 70, 5906 (1979).Google Scholar
  9. 9.
    R.V. Ambartzumian, Yu. A. Gorokhov, G.N. Makarov, A.A. Puretzky, and N.P. Furzikov, Chem. Phys. Lett. 45, 231 (1977).ADSCrossRefGoogle Scholar
  10. 10.
    R.V. Ambartzumian, G.N. Makarov, and A.A. Puretzky, Appl. Phys. 22, 71 (1980).ADSCrossRefGoogle Scholar
  11. 11.
    Z. Karny, A. Gupta, R.N. Zare, S.T. Lin, J. Nieman, and A.M. Ronn, Chem. Phys. 37, 15 (1979).CrossRefGoogle Scholar
  12. 12.
    J. Nieman and A.M. Ronn, Opt. Eng. 19, 39 (1980).Google Scholar
  13. 13.
    I. Burak and J.Y. Tsao, Chem. Phys. Lett. 77, 53 (1981).CrossRefGoogle Scholar
  14. 14.
    A. Nitzan and J. Jortner, a) Chem Phys. Lett. 60,1 (1978). b) J. Chem. Phys. 71, 3524 (1979)ADSCrossRefGoogle Scholar
  15. 15.
    T.A. Watson, M. Mangir, C. Wittig, and M.R. Levy, J. Chem Phys., in press.Google Scholar
  16. 16.
    T.A. Watson, M. Mangir, C. Wittig, and M.R. Levy, J. Phys. Chem., in press.Google Scholar
  17. 17.
    S.W. Benson, private communication.Google Scholar
  18. 18.
    N.V. Chekalin, V.S. Dolzhikov, V.S. Letokhov, V.N. Lokhman, and A.N. Shibanov, Appl. Phys. 12, 191 (1977).ADSCrossRefGoogle Scholar
  19. 19.
    J.H. Hall, Jr., M.L. Lesiecki, and W.A. Guillory, J. Chem. Phys. 68, 2247 (1978).ADSCrossRefGoogle Scholar
  20. 20.
    N.V. Chekalin, V.S. Letokhov, V.N. Lokhman, and A.N. Shibanov, Chem. Phys. 36, 415 (1979).CrossRefGoogle Scholar
  21. 21.
    S.V. Filseth, J. Danon, D. Feldmann, J.D. Campbell, and K.H. Welge, Chem. Phys. Lett. 66, 329 (1979).ADSCrossRefGoogle Scholar
  22. 22.
    C.R. Quick, Jr., A.B. Horwitz, R.E. Weston, Jr., and G.W. Flynn, Chem. Phys. Lett. 72, 352 (1980); see also references cited therein.ADSCrossRefGoogle Scholar
  23. 23.
    C. Reiser, F.M. Lussier, C.G. Jensen, and J.I. Steinfeld, J. Am. Chem. Soc. 101, 350 (1979).CrossRefGoogle Scholar
  24. 24.
    Aa.S. Sudbo, P.A. Schulz, E.R. Grant, Y.R. Shen, and Y.T. Lee, J. Chem. Phys. 68, 1306 (1978).ADSCrossRefGoogle Scholar
  25. 25.
    J. Caballero and C. Wittig, submitted.Google Scholar
  26. 26.
    M. Spoliti, J.H. Thirtle, and T.M. Dunn, J. Mol. Spectr. 52, 146 (1974).ADSCrossRefGoogle Scholar
  27. 27.
    V.E. Bondybey, Chem. Phys. 18, 293 (1974).ADSCrossRefGoogle Scholar
  28. 28.
    J.R. McDonald, Chem. Phys. 19, 423 (1975).ADSCrossRefGoogle Scholar
  29. 29.
    R.N. Dixon and C.R. Webster, J. Mol. Spectr. 62, 271 (1976).ADSCrossRefGoogle Scholar
  30. 30.
    W.R. Gentry and C.F. Giese, Rev. Sci. Instr. 49, 595 (1978).ADSCrossRefGoogle Scholar
  31. 31.
    E.A. Entemann and D.R. Herschbach, Disc. Farad. Soc. 44, 289 (1967).CrossRefGoogle Scholar
  32. 32.
    S.A. Safron, N.D. Weinstein, D.R. Herschbach, and J.C. Tully, Chem. Phys. Lett. 12, 564 (1972),ADSCrossRefGoogle Scholar
  33. 33.
    Aa.S. Sudbo, P.A. Schulz, E.H. Grant, Y.R. Shen, and Y.T. Lee, J. Chem. Phys. 70, 912 (1979).ADSCrossRefGoogle Scholar
  34. 34.
    Aa.S. Sudbo, P.A. Schulz, Y.R. Shen, and Y.T. Lee, J. Chem. Phys. 69, 2312 (1978).ADSCrossRefGoogle Scholar
  35. 35.
    G. Herzberg, “Electronic Spectra of Polyatomic Molecules” ( Van Nostrand, N.Y., 1966 ).Google Scholar
  36. 36.
    S. Trajmar, J.K. Rice, P.S.P. Wei, and A. Kuppermann, Chem. Phys. Lett. 1, 703 (1968).ADSCrossRefGoogle Scholar
  37. 37.
    D. Demoulin, Chem. Phys. 11, 329 (1975).ADSCrossRefGoogle Scholar
  38. 38.
    W.R.M. Graham, K.I. Dismuke, and W. Weltner, Jr., J. Chem. Phys. 60, 3817 (1974).ADSCrossRefGoogle Scholar
  39. 39.
    M. Okabe, J. Chem. Phys. 62 2782 (1975).ADSCrossRefGoogle Scholar
  40. 40.
    K.H. Becker, D, Maaks, and M. Shurgers, Z. Naturforsch. 26a, 1770 (1977).ADSGoogle Scholar
  41. 41.
    J.R. McDonald, A.P. Baronavski, and V.M. Donnelly, Chem. Phys. 33, 161 (1978).CrossRefGoogle Scholar
  42. 42.
    S. Shingkuo, S.D. Peyerimhoff, and R.J. Buenker, J. Mol. Spectr. 74, 124 (1979).ADSCrossRefGoogle Scholar
  43. 43.
    M.E. Jacox, Chem. Phys. 7, 424 (1975).ADSCrossRefGoogle Scholar
  44. 44.
    H. Reisler, M. Mangir, and C. Wittig, Chem Phys. 47, 49 (1980).CrossRefGoogle Scholar
  45. 45.
    V.A. Job and G.W. King, J. Mol. Spectr. 19, 155, 178 (1966).ADSCrossRefGoogle Scholar
  46. 46.
    M. Guelin and P. Thaddeus, Astrophys. J. 212, L81 (1977).ADSCrossRefGoogle Scholar
  47. 47.
    S. Wilson and S. Green, Astrophys. J. 212, L87 (1977).ADSCrossRefGoogle Scholar
  48. 48.
    R. Thomson and P.A. Warsop, Trans. Farad. Soc. 65, 2806 (1969).CrossRefGoogle Scholar
  49. 49.
    J.L. Lyman, J.W. Hudson, and S.M. Freund, Opt. Commun. 21, 119 (1977).ADSCrossRefGoogle Scholar
  50. 50.
    D.S. King and J.C. Stephenson, Chem. Phys. Lett. 66, 33 (1979).ADSCrossRefGoogle Scholar
  51. 51.
    A.M. Renlund, H. Reisler, and C. Wittig, Chem Phys. Lett. 78, 40 (1981).ADSCrossRefGoogle Scholar
  52. 52.
    H. Reisler, M.S. Mangir, and C. Wittig, J. Chem. Phys. 71, 2109 (1979).ADSCrossRefGoogle Scholar
  53. 53.
    R.A. Dougal, C.R. Jones, M. Gundersen and L.Y. Nelson, Appl. Optics 18, 1311 (1979).ADSCrossRefGoogle Scholar
  54. 54.
    H. Reisler, F. Kong, A.M. Renlund and C. Wittig, submitted.Google Scholar
  55. 55.
    G. Herzberg, “Molecular Spectra and Molecular Structure, Vol. 1, Spectra of Diatomic Molecules” (Van Nostrand, Princeton, 1950).Google Scholar
  56. 56.
    C.M. Miller and R.N. Zare, Chem. Phys. Lett. 71, 376 (1980).ADSCrossRefGoogle Scholar
  57. 57.
    M.N.R. Ashfold, G. Hancock, and M.L. Hardaker, J. Photochem. 14, 85 (1980).CrossRefGoogle Scholar
  58. 58.
    W.L. Hase and D.L. Bunker, Quantum Chemistry Program Exchange, No. 234.Google Scholar
  59. 59.
    See, e.g., P.J. Robinson and K.A. Holbrook, “Unimolecular Reactions”, (Wiley Interscience, N.Y. 1972); W. Forst, “Theory of Unimolecular Reactions” (Academic Press, N.Y. 1973).Google Scholar

Copyright information

© Plenum Press, New York 1983

Authors and Affiliations

  • Martin R. Levy
    • 1
  • Anita M. Renlund
    • 2
  • Tom A. Watson
    • 2
  • Metin S. Mangir
    • 2
  • Hanna Reisler
    • 2
  • Curt Wittig
    • 2
  1. 1.Corporate Research Science LaboratoriesExxon Research and Engineering CompanyLindenUSA
  2. 2.Departments of E. E., Physics, and ChemistryUniversity of Southern CaliforniaLos AngelesUSA

Personalised recommendations