Skip to main content

Thank you for visiting nature.com. You are using a browser version with limited support for CSS. To obtain the best experience, we recommend you use a more up to date browser (or turn off compatibility mode in Internet Explorer). In the meantime, to ensure continued support, we are displaying the site without styles and JavaScript.

  • Letter
  • Published:

Vibrational Relaxation of HBr(ν″ = 1) by HCl at 300 K

Abstract

RECENT interest in chemical lasers has been strongly directed towards systems which give rise to vibrationally excited hydrogen halide molecules1–7. The efficiency of such systems will clearly depend on the rate at which vibrational energy is removed from the products of the chemical reaction, and considerable effort has been made to obtain the relevant rate data. Airey8 has described a pulsed laser system based on the reaction9,10 and has discussed the various energy transfer processes which may be involved. Moore et al. and Airey (see ref. 11) have further used reaction (1) to obtain rate data for the process. We have independently undertaken an extensive study of energy transfer processes involving the hydrogen bromide molecule using rather different techniques to monitor the vibrationally excited species and wish to report here rate data for the vibrational relaxation of HBr(ν″ = 1) by HCl. In our system, vibrationally excited HBr is produced by the fast reaction9,10 following the flash photolysis of HBr (pHBr = 33.3 Nm−2) in the presence of Br2 ( p Br 2 = 4.1 Nm−2), and excess Ar (pAr = 13.3 k Nm−2) to prevent a significant rise above room temperature (T = 300 K). Near resonant exchange processes rapidly reduced the initial vibrational distribution in HBr to a condition where a non-Boltzmann distribution in HBr(ν″ = 1) is observed. Relaxation from this level to ν″ = 0 can then be conveniently monitored, using kinetic absorption spectroscopy in the vacuum ultraviolet12, to observe the (0,1) transition of the strongly predissociated system connecting the ground state with “state [6]” (ν0 = 70,526 cm−1) (refs. 13, 14).

This is a preview of subscription content, access via your institution

Access options

Rent or buy this article

Prices vary by article type

from$1.95

to$39.95

Prices may be subject to local taxes which are calculated during checkout

Similar content being viewed by others

References

  1. Parker, J. H., and Pimentel, G. C., J. Chem. Phys., 51, 91 (1969).

    Article  ADS  CAS  Google Scholar 

  2. Berry, M. J., and Pimentel, G. C., J. Chem. Phys., 51, 2274 (1969).

    Article  ADS  CAS  Google Scholar 

  3. Berry, M. J., and Pimentel, G. C., J. Chem. Phys., 49, 5190 (1969).

    Article  ADS  Google Scholar 

  4. Kasper, J. V. V., and Pimentel, G. C., Phys. Rev. Lett., 14, 352 (1965).

    Article  ADS  CAS  Google Scholar 

  5. Corneil, P. H., and Pimentel, G. C., J. Chem. Phys., 49, 1379 (1968).

    Article  ADS  CAS  Google Scholar 

  6. Spencer, D. J., Jacobs, T. A., Minols, H., and Gross, B. W. F., Intern. J. Chem. Kinetics, 1, 493 (1969).

    Article  CAS  Google Scholar 

  7. Cool, T. A., Stephens, R. R., and Falk, T. J., Intern. J. Chem. Kinetics, 1, 495 (1969).

    Article  CAS  Google Scholar 

  8. Airey, J. R., J. Chem. Phys., 52, 156 (1970).

    Article  ADS  CAS  Google Scholar 

  9. Anlauf, K. G., Maylotte, D. H., Pacey, P. D., and Polanyi, J. C., Phys. Lett., 24, 209 (1967).

    Article  Google Scholar 

  10. Anlauf, K. G., Kuntz, P. J., Maylotte, D. H., Pacey, P. D., and Polanyi, J. C., Disc. Faraday Soc., 44, 183 (1967).

    Article  Google Scholar 

  11. Cohen, N., Report of Second Conference on Chemical and Molecular Lasers (May 1969, St Louis, Missouri), Intern. J. Chem. Kinetics, 1, 479 (1969).

    Google Scholar 

  12. Donovan, R. J., Husain, D., and Stevenson, C. D., Trans. Faraday Soc., 65, 2941 (1969).

    Article  CAS  Google Scholar 

  13. Barrow, R. F., and Stamper, J. G., Proc. Roy. Soc., A, 263, 259 (1961).

    Article  ADS  CAS  Google Scholar 

  14. Barrow, R. F., and Stamper, J. G., Proc. Roy. Soc., A, 263, 277 (1961).

    Article  ADS  Google Scholar 

  15. Wheaton, J. E. G., Appl. Optics, 3, 1247 (1964).

    Article  ADS  Google Scholar 

  16. Chen, H. L., Stephenson, J. C., and Moore, C. B., Chem. Phys. Lett., 2, 593 (1968).

    Article  ADS  CAS  Google Scholar 

  17. Lambert, J. D., and Salter, R., Proc. Roy. Soc., A, 253, 277 (1959).

    Article  ADS  CAS  Google Scholar 

Download references

Author information

Authors and Affiliations

Authors

Rights and permissions

Reprints and permissions

About this article

Cite this article

DONOVAN, R., HUSAIN, D. & STEVENSON, C. Vibrational Relaxation of HBr(ν″ = 1) by HCl at 300 K. Nature 227, 602–603 (1970). https://doi.org/10.1038/227602a0

Download citation

  • Received:

  • Revised:

  • Issue Date:

  • DOI: https://doi.org/10.1038/227602a0

Comments

By submitting a comment you agree to abide by our Terms and Community Guidelines. If you find something abusive or that does not comply with our terms or guidelines please flag it as inappropriate.

Search

Quick links

Nature Briefing

Sign up for the Nature Briefing newsletter — what matters in science, free to your inbox daily.

Get the most important science stories of the day, free in your inbox. Sign up for Nature Briefing