Vibrational Predissociation of van der Waals Molecules and Intermolecular Potential Energy Surfaces

  • George E. Ewing

Abstract

Historically, spectroscopic experiments have been primarily responsible for defining structures and potential energy surfaces of chemically bonded molecules. These experimental results and the theoretical models of quantum chemistry have been worked up together to give us the detailed understanding of the chemical bond that we now have. In the last decade this history is being rerun, but now the objects of study are van der Waals molecules. Spectroscopy on these weakly bound complexes, produced at low temperatures where their stability is favored, has yielded structures and, often with the help of scattering experiments, rather complete intermolecular potential energy surface mappings. The structures that have been found are often surprising since for van der Waals molecules we do not have the reliable guides for geometries that we have for chemically bonded molecules.

Keywords

Potential Energy Surface Vibrational Energy Energy Transfer Process Isotropic Potential Centrifugal Barrier 
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.

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References

  1. 1.
    W. Klemperer, Molecular spectroscopy of weakly bound complexes, Ber. Bunsenges. Phys. Chem. 18: 128 (1974).Google Scholar
  2. 2.
    G. Ewing, Structure and properties of van der Waals molecules, Acc. Chem. Res. 8: 185 (1975).CrossRefGoogle Scholar
  3. 3.
    B. Blaney and G. Ewing, Van der Waals molecules, Ann. Rev. Phys. Chem. 27: 553 (1976).CrossRefGoogle Scholar
  4. 4.
    G. Ewing, The spectroscopy of van der Waals molecules, Can. J. Phys. 54: 487 (1976).CrossRefGoogle Scholar
  5. 5.
    R. J. LeRoy and J. S. Carley, Spectroscopy and potential energy surfaces of van der Waals molecules, Advan. Chem. Phys. 42: 353 (1980).CrossRefGoogle Scholar
  6. 6.
    D. H. Levy. Laser spectroscopy of cold gas-phase molecules, Annu. Rev. Phys. Chem. 31: 197 (1980).CrossRefGoogle Scholar
  7. 7.
    J. D. van der Waals, Dissertation, Leiden, The Netherlands, 1972.Google Scholar
  8. 8.
    T. Kihara, “Intermolecular Forces”, Wiley, New York (1978).Google Scholar
  9. 9.
    J. M. Parson, P. E. Siska, and Y. T. Lee, Intermolecular potentials from crossed-beam differential elastic scattering measurements. IV. Ar + Ar, J. Chem. Phys. 56: 1511 (1972).CrossRefGoogle Scholar
  10. 10.
    K. Docken and T. P. Schafer, Spectroscopic information on ground state Ar2, Kr2 and Xe2 from interatomic potentials, J. Mol. Spectry. 46: 454 (1973).CrossRefGoogle Scholar
  11. 11.
    G. Henderson and G. Ewing, Infrared spectrum, structure and properties of the N2-Ar van der Waals molecule, Mol. Phys. 27: 903 (1974).CrossRefGoogle Scholar
  12. 12.
    A. R. W. McKellar and H. L. Welsh, Spectra of (H2)2, (D2)2 and H2-D2 van der Waals complexes, Can. J. Phys. 52: 1082 (1974).Google Scholar
  13. 13.
    L. A. Curtiss and J. A. Pople, Ab initio calculation of the force field of the hydrogen fluoride dimer. J. Mol. Spectry 61: 1 (1976).Google Scholar
  14. 14.
    D. Stogryn and J. Hirschfelder, Contribution of bound, meta-stable, and free molecules to the second virial coefficient and some properties of double molecules, J. Chem. Phys. 31: 1531 (1959).CrossRefGoogle Scholar
  15. 15.
    G. Mahan and M. Lapp, Bound states of alkali and noble-gas atoms, Phys. Rev. 179: 19 (1969).CrossRefGoogle Scholar
  16. 16.
    G. Ewing, The role of van der Waals molecules in vibrational relaxation processes, Chem. Phys. 29: 253 (1978).CrossRefGoogle Scholar
  17. 17.
    L. Pauling, “The Nature of the Chemical Bond”, 2nd edition, Cornell University Press, Ithaca (1948).Google Scholar
  18. 18.
    R. W. G. Wyckoff, “Crystal Structures”, 2nd edition, Vol. 1, Interscience, New York (1960).Google Scholar
  19. 19.
    A. R. W. McKellar and H. L. Welsh, Anisotropic intermolecular force effects in spectra of H2-and D2-rare gas complexes, J. Chem. Phys. 55: 595 (1971).CrossRefGoogle Scholar
  20. 20.
    S. E. Novick, S. J. Harris, and W. Klemperer, Determination of the structure of ArHCl, J. Chem. Phys. 59: 2273 (1973).CrossRefGoogle Scholar
  21. 21.
    A. M. Dunker and R. G. Gordon, Calculations on the HCl-Ar van der Waals complex, J. Chem. Phys. 64: 354 (1975).CrossRefGoogle Scholar
  22. 22.
    T. Dyke, B. J. Howard, and W. Klemperer, Radiofrequency and microwave spectrum of the hydrogen fluoride dimer: A nonrigid molecule, J. Chem. Phys. 56: 2442 (1972).CrossRefGoogle Scholar
  23. 23.
    C. A. Long and G. Ewing, Spectroscopic investigation of van der Waals molecules. I. The infrared and visible spectra of (O2)2, J. Chem. Phys. 58: 4824 (1973).CrossRefGoogle Scholar
  24. 24.
    J. E. Grabenstetter and R. J. LeRoy, Widths (lifetimes) and energies for metastable levels of atom-diatom complexes, Chem. Phys. 42: 41 (1979).CrossRefGoogle Scholar
  25. J. A. Beswick and A. Reguena, Rotational predissociation of triatomic van der Waals molecules, J. Chem. Phys. 72: 3018 (1980).CrossRefGoogle Scholar
  26. 25.
    R. E. Leckenby and E. J. Robbins, The observation of double molecules in gases, Proc. Roy. Soc. Lond., Ser. A 291: 389 (1966).CrossRefGoogle Scholar
  27. 26.
    R. E. Smalley, L. Wharton, and D. H. Levy, Molecular optical spectroscopy with supersonic beams and jets. Acc. Chem. Res. 10: 139 (1977).CrossRefGoogle Scholar
  28. 27.
    K. E. Johnson, L. Wharton, and D. H. Levy, The photodissociation lifetime of the van der Waals molecule I2He, J. Chem. Phys. 69: 2719 (1978).CrossRefGoogle Scholar
  29. 28.
    T. E. Gough, K. E. Miller, and G. Scoles, Photo-induced vibrational predissociation of the van der Waals molecule (N2O)2, J. Chem. Phys. 69: 1588 (1978).CrossRefGoogle Scholar
  30. 29.
    L. S. Bernstein and C. E. Kolb, Understanding the infrared continuum spectrum of the N2O dimer and other van der Waals complexes at low temperatures, J. Chem. Phys. 71: 2818 (1979).CrossRefGoogle Scholar
  31. 30.
    W. R. Gentry, M. Hoffbauer, and C. Giese, Photodissociation of van der Waals dimers in pulsed molecular beams, IV International Symposium on Molecular Beams, Trento, Italy (1979).Google Scholar
  32. 31.
    M. P. Casassa, D. S. Bomse, J. L. Beauchamp, and K. C. Janda, Infrared photochemistry of ethylene clusters, J. Chem. Phys. 72: 6805 (1980).CrossRefGoogle Scholar
  33. 32.
    T. Hirooka, S. L. Anderson, P. Tiedemann, B. Mahan, and Y. T. Lee, Vibrational predissociation of vibrationally excited hydrogen molecule dimers, Lawrence Berkeley Laboratory, preprint LBL-8034.Google Scholar
  34. 33.
    R. Schultz, A. Sudbo, Y. T. Lee, and Y. R. Shen, International Quantum Electronics Conference, Optical Society of America, Atlanta (1978).Google Scholar
  35. 34.
    D. A. Dixon and D. R. Herschbach, Energy transfer process involving van der Waals bonds, Ber. Bunsenges. Phys. Chem. 81: 145 (1977).CrossRefGoogle Scholar
  36. 35.
    C. A. Coulson and G. N. Robertson, A theory of the infrared absorption spectra of hydrogen-bonded species. I, Proc. Roy. Soc. Lond., Ser. A 337: 167 (1974).CrossRefGoogle Scholar
  37. 36.
    J. Beswick and J. Jortner, Vibrational predissociation of triatomic van der Waals molecules, J. Chem. Phys. 68: 2277 (1978).CrossRefGoogle Scholar
  38. 37.
    G. Ewing, Vibrational predissociation in hydrogen bonded complexes, J. Chem. Phys. 72: 2096 (1980).CrossRefGoogle Scholar
  39. 38.
    K. F. Herzfeld and T. A. Litovitz, “Absorption and Dispersion of Ultrasonic Waves”, Academic, New York (1959).Google Scholar
  40. 39.
    E. Bauer, Method of calculating cross sections for molecular collisions, J. Chem. Phys. 23: 1087 (1955).CrossRefGoogle Scholar
  41. 40.
    R. G. Gordon and J. K. Cashion, Intermolecular potentials and the infrared spectrum of the molecular complex (H2)2, J. Chem. Phys. 44: 1190 (1966).CrossRefGoogle Scholar
  42. 41.
    J. Beswick and J. Jortner, Intermolecular dynamics of some van der Waals dimers, J. Chem. Phys. 71: 4737 (1979).CrossRefGoogle Scholar
  43. 42.
    J. A. Beswick, G. Delgado-Barrio, and J. Jortner, Vibrational predissociation lifetimes of the van der Waals molecule HeI2, J. Chem. Phys. 70: 3895 (1979).CrossRefGoogle Scholar
  44. 43.
    G. Ewing, A guide to the lifetimes of vibrationally excited van der Waals molecules: The momentum gap, J. Chem. Phys. 71: 3143 (1979).CrossRefGoogle Scholar
  45. 44.
    P. Dehmer and W. Chupka, Very high resolution study of photo-absorption, photoionization, and predissociation of H2 +, J. Chem. Phys. 65: 2243 (1976).CrossRefGoogle Scholar
  46. 45.
    J. D. Lambert, “Vibrational and Rotational Relaxation in Gases”, Clarendon, Oxford (1977).Google Scholar
  47. 46.
    D. Morales and G. Ewing, Vibrational predissociation of the van der Waals molecule (N2O)2, Chem. Phys. 53: 141 (1980).CrossRefGoogle Scholar
  48. 47.
    M. S. Child and C. J. Ashton, General discussion, Faraday Disc. Chem. Soc. 62: 307 (1976).Google Scholar
  49. 48.
    F. Legay, Vibrational relaxation in matrices, in: “Chemical and Biological Applications of Lasers”, C. B. Moore, ed., Academic, New York (1977), p. 43.CrossRefGoogle Scholar
  50. 49.
    T. Gough, personal communication.Google Scholar
  51. 50.
    R. A. Marcus, Energy distributions in unimolecular reactions, Ber. Bunsenges. Phys. Chem. 81: 190 (1977).CrossRefGoogle Scholar
  52. 51.
    D. Lucas and G. Ewing, IR photodesorption of hydrogen isotopes, Amer. Chem. Soc. Las Vegas, NV (1980), paper 73.Google Scholar

Copyright information

© Springer Science+Business Media New York 1981

Authors and Affiliations

  • George E. Ewing
    • 1
  1. 1.Department of ChemistryIndiana UniversityBloomingtonUSA

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