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.

  • Article
  • Published:

The rate of the F + H2 reaction at very low temperatures

Nature Chemistry volume 6, pages 141–145 (2014)Cite this article

Subjects

Abstract

The prototypical F + H2 → HF + H reaction possesses a substantial energetic barrier (~800 K) and might therefore be expected to slow to a negligible rate at low temperatures. It is, however, the only source of interstellar HF, which has been detected in a wide range of cold (10–100 K) environments. In fact, the reaction does take place efficiently at low temperatures due to quantum-mechanical tunnelling. Rate constant measurements at such temperatures have essentially been limited to fast barrierless reactions, such as those between two radicals. Using uniform supersonic hydrogen flows we can now report direct experimental measurements of the rate of this reaction down to a temperature of 11 K, in remarkable agreement with state-of-the-art quantum reactive scattering calculations. The results will allow a stronger link to be made between observations of interstellar HF and the abundance of the most common interstellar molecule, H2, and hence a more accurate estimation of the total mass of astronomical objects.

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

Access options

Buy this article

  • Purchase on Springer Link
  • Instant access to full article PDF
Buy now

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

Figure 1: Results for the determination of the F + H2 reaction rate coefficient at 77 K.
Figure 2: Hydrogen atom product LIF intensity as a function of photolysis–probe laser delay time.
Figure 3: Comparison of rate coefficients k for the F(2PJ) + n-H2 → HF + H reaction as a function of temperature.
Figure 4: Low-temperature F + H2 (j = 0, 1) rate coefficients.
Figure 5: Values of the predicted abundance ratio n(HF) to n(H2) for typical diffuse interstellar cloud conditions.

Similar content being viewed by others

References

  1. Levine, R. D. & Bernstein, R. B. Molecular Reaction Dynamics and Chemical Reactivity (Oxford Univ. Press, 1987).

    Google Scholar 

  2. Neumark, D. M., Wodtke, A. M., Robinson, G. N., Hayden, C. C. & Lee, Y. T. Molecular-beam studies of the F + H2 reaction. J. Chem. Phys. 82, 3045–3066 (1985).

    Article  CAS  Google Scholar 

  3. Skodje, R. T. et al. Resonance-mediated chemical reaction: F +HD → HF + D. Phys. Rev. Lett. 85, 1206–1209 (2000).

    Article  CAS  Google Scholar 

  4. Qiu, M. H. et al. Observation of Feshbach resonances in the F + H2 → HF + H reaction. Science 311, 1440–1443 (2006).

    Article  CAS  Google Scholar 

  5. Che, L. et al. Breakdown of the Born–Oppenheimer approximation in the F + o-D2 → DF + D reaction. Science 317, 1061–1064 (2007).

    Article  CAS  Google Scholar 

  6. Althorpe, S. C. Setting the trap for reactive resonances. Science 327, 1460–1461 (2010).

    Article  CAS  Google Scholar 

  7. Stark, K. & Werner, H. J. An accurate multireference configuration interaction calculation of the potential energy surface for the F + H2 → HF + H reaction. J. Chem. Phys. 104, 6515–6530 (1996).

    Article  CAS  Google Scholar 

  8. Li, G., Werner, H-J., Lique, F. & Alexander, M. H. New ab initio potential energy surfaces for the F + H2 reaction. J. Chem. Phys. 127, 174302 (2007).

    Article  Google Scholar 

  9. Alexander, M. H., Manolopoulos, D. E. & Werner, H. J. An investigation of the F + H2 reaction based on a full ab initio description of the open-shell character of the F(2P) atom. J. Chem. Phys. 113, 11084–11100 (2000).

    Article  CAS  Google Scholar 

  10. Aquilanti, V. et al. Benchmark rate constants by the hyperquantization algorithm. The F + H2 reaction for various potential energy surfaces: features of the entrance channel and of the transition state, and low temperature reactivity. Chem. Phys. 308, 237–253 (2005).

    Article  CAS  Google Scholar 

  11. Manolopoulos, D. E. The dynamics of the F + H2 reaction. J. Chem. Soc. Faraday Trans. 93, 673–683 (1997).

    Article  CAS  Google Scholar 

  12. Lique, F. et al. Evidence for excited spin–orbit state reaction dynamics in F + H2: theory and experiment. J. Chem. Phys. 128, 084313 (2008).

    Article  Google Scholar 

  13. Neufeld, D. A., Zmuidzinas, J., Schilke, P. & Phillips, T. G. Discovery of interstellar hydrogen fluoride. Astrophys. J. 488, L141–L144 (1997).

    Article  CAS  Google Scholar 

  14. Agundez, M. et al. HIFI detection of hydrogen fluoride in the carbon star envelope IRC+10216. Astron. Astrophys. 533, L6 (2011).

    Article  Google Scholar 

  15. Emprechtinger, M. et al. Hydrogen fluoride in high-mass star-forming regions. Astrophys. J. 756, 136 (2012).

    Article  Google Scholar 

  16. Monje, R. R. et al. Herschel/HIFI observations of hydrogen fluoride toward Sagittarius B2(M). Astrophys. J. 734, L23 (2011).

    Article  Google Scholar 

  17. Monje, R. R. et al. Discovery of hydrogen fluoride in the cloverleaf quasar at z = 2.56. Astrophys. J. 742, L21 (2011).

    Article  Google Scholar 

  18. Neufeld, D. A. et al. Strong absorption by interstellar hydrogen fluoride: Herschel/HIFI observations of the sight-line to G10.6-0.4 (W31C). Astron. Astrophys. 518, L108 (2010).

    Article  Google Scholar 

  19. Phillips, T. G. et al. Herschel observations of EXtra-Ordinary Sources (HEXOS): detection of hydrogen fluoride in absorption towards Orion KL. Astron. Astrophys. 518, L109 (2010).

    Article  Google Scholar 

  20. Sonnentrucker, P. et al. Detection of hydrogen fluoride absorption in diffuse molecular clouds with Herschel/HIFI: an ubiquitous tracer of molecular gas. Astron. Astrophys. 521, L12 (2010).

    Article  Google Scholar 

  21. van der Tak, F. The first results from the Herschel-HIFI mission. Adv. Space Res. 49, 1395–1407 (2012).

    Article  Google Scholar 

  22. Zhu, C., Krems, R., Dalgarno, A. & Balakrishnan, N. Chemistry of hydrogen fluoride in the interstellar medium. Astrophys. J. 577, 795–797 (2002).

    Article  CAS  Google Scholar 

  23. Neufeld, D. A., Wolfire, M. G. & Schilke, P. The chemistry of fluorine-bearing molecules in diffuse and dense interstellar gas clouds. Astrophys. J. 628, 260–274 (2005).

    Article  CAS  Google Scholar 

  24. Wurzberg, E. & Houston, P. L. The temperature-dependence of absolute rate constants for the F + H2 and F + D2 reactions. J. Chem. Phys. 72, 4811–4814 (1980).

    Article  CAS  Google Scholar 

  25. Stevens, P. S., Brune, W. H. & Anderson, J. G. Kinetic and mechanistic investigations of F + H2O/D2O and F + H2/D2 over the temperature-range 240–373 K. J. Phys. Chem. 93, 4068–4079 (1989).

    Article  CAS  Google Scholar 

  26. Lique, F., Li, G. L., Werner, H. J. & Alexander, M. H. Communication: non-adiabatic coupling and resonances in the F + H2 reaction at low energies. J. Chem. Phys. 134, 231101 (2011).

    Article  Google Scholar 

  27. Jaques, C. et al. Photoinitiated processes in complexes—subpicosecond studies of CO2-HI and stereospecificity in Ar-HX. J. Chem. Soc. Faraday Trans. 89, 1419–1425 (1993).

    Article  CAS  Google Scholar 

  28. Persky, A. & Kornweitz, H. The kinetics of the reaction F + H2 → HF + H. A critical review of literature data. Int. J. Chem. Kinet. 29, 67–71 (1997).

    Article  CAS  Google Scholar 

  29. Aquilanti, V. et al. Exact activation energies and phenomenological description of quantum tunneling for model potential energy surfaces. The F + H2 reaction at low temperature. Chem. Phys. 398, 186–191 (2012).

    Article  CAS  Google Scholar 

  30. Neufeld, D. A. & Wolfire, M. G. The chemistry of interstellar molecules containing the halogen elements. Astrophys. J. 706, 1594–1604 (2009).

    Article  CAS  Google Scholar 

  31. Godard, B. et al. Comparative study of CH+ and SH+ absorption lines observed towards distant star-forming regions. Astron. Astrophys. 540, A87 (2012).

    Article  Google Scholar 

  32. Zhu, C., Krems, R., Dalgarno, A. & Balakrishnan, N. Erratum: ‘Chemistry of hydrogen fluoride in the interstellar medium’ (vol. 577, p. 795, 2002). Astrophys. J. 703, 1176 (2009).

    Article  CAS  Google Scholar 

  33. Indriolo, N., Neufeld, D. A., Seifahrt, A. & Richter, M. J. Direct determination of the HF/H2 abundance ratio in interstellar gas. Astrophys. J. 764, 188 (2013).

    Article  Google Scholar 

  34. Sims, I. R. et al. Ultralow temperature kinetics of neutral–neutral reactions—the technique and results for the reactions CN + O2 down to 13 K and CN + NH3 down to 25 K. J. Chem. Phys. 100, 4229–4241 (1994).

    Article  CAS  Google Scholar 

  35. Nizkorodov, S. A., Harper, W. W. & Nesbitt, D. J. State-to-state reaction dynamics in crossed supersonic jets: threshold evidence for non-adiabatic channels in F + H2 . Faraday Discuss. 113, 107–117 (1999).

    Article  CAS  Google Scholar 

  36. Werner, H. J., Kallay, M. & Gauss, J. The barrier height of the F + H2 reaction revisited: coupled-cluster and multireference configuration-interaction benchmark calculations. J. Chem. Phys. 128, 034305 (2008).

    Article  Google Scholar 

  37. Skouteris, D., Castillo, J. F. & Manolopoulos, D. E. ABC: a quantum reactive scattering program. Comput. Phys. Commun. 133, 128–135 (2000).

    Article  CAS  Google Scholar 

Download references

Acknowledgements

The authors acknowledge support from the French Agence Nationale de Recherche (ANR Blanc Programme, Project CRNS) and the Centre National de la Recherche Scientifique (CNRS) via the Institut National des Sciences de l'Univers (INSU) Programme National de Physique et Chimie du Milieu Interstellaire. The authors thank D. Travers, J. Courbe, E. Gallou and J. Sorieux for technical support. M.T. thanks the French Ministère de l'Enseignement Supérieur et de la Recherche for a research studentship (Allocation Fléchée). S.D.L.P. acknowledges financial support from the Institut Universitaire de France. M.H.A. is grateful to the US National Science Foundation for support (grant CHE–1213332), to H-J. Werner and G. Li for their invaluable contributions in the construction of the LWAL FH2 PESs and to N. Brown for her help in estimating the F–H2 and H–H2 diffusion rate coefficients. The authors thank B. Godard for discussions regarding his astrochemical model.

Author information

Authors and Affiliations

  1. Institut de Physique de Rennes, UMR CNRS-UR1 6251, Université de Rennes 1, 263 Avenue du Général Leclerc, Rennes Cedex, 35042, France

    Meryem Tizniti, Sébastien D. Le Picard, Coralie Berteloite, André Canosa & Ian R. Sims

  2. LOMC, UMR 6294, CNRS-Université du Havre, 25 rue Philippe Lebon, BP 540, Le Havre, 76058, France

    François Lique

  3. Department of Chemistry and Biochemistry and Institute for Physical Science and Technology, University of Maryland, College Park, Maryland, 20742-2021, USA

    Millard H. Alexander

Authors
  1. Meryem Tizniti
    View author publications

    You can also search for this author in PubMed Google Scholar

  2. Sébastien D. Le Picard
    View author publications

    You can also search for this author in PubMed Google Scholar

  3. François Lique
    View author publications

    You can also search for this author in PubMed Google Scholar

  4. Coralie Berteloite
    View author publications

    You can also search for this author in PubMed Google Scholar

  5. André Canosa
    View author publications

    You can also search for this author in PubMed Google Scholar

  6. Millard H. Alexander
    View author publications

    You can also search for this author in PubMed Google Scholar

  7. Ian R. Sims
    View author publications

    You can also search for this author in PubMed Google Scholar

Contributions

M.T., S.D.L.P., C.B. and I.R.S. carried out the experimental measurements and data analysis. A.C. designed the low-temperature hydrogen Laval nozzles. F.L. and M.H.A. performed the theoretical calculations. All authors discussed the results and commented on the manuscript.

Corresponding authors

Correspondence to Millard H. Alexander or Ian R. Sims.

Ethics declarations

Competing interests

The authors declare no competing financial interests.

Supplementary information

Supplementary information

Supplementary information (PDF 1483 kb)

Rights and permissions

Reprints and permissions

About this article

Cite this article

Tizniti, M., Le Picard, S., Lique, F. et al. The rate of the F + H2 reaction at very low temperatures. Nature Chem 6, 141–145 (2014). https://doi.org/10.1038/nchem.1835

Download citation

  • Received:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1038/nchem.1835

This article is cited by

Search

Advanced 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