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:

Inelastic scattering of hydroxyl radicals with helium and argon by velocity-map imaging

Abstract

The hydroxyl radical (OH) is one of the most interesting molecules in molecular dynamics. In particular, inelastic collisions of free radicals such as OH are profoundly important in environments ranging from combustion to astrochemistry. However, measuring the velocities of OH molecules in specific internal quantum states has proven to be very difficult. A method that can provide this important information is velocity-map imaging. Although this technique is very widely applicable in principle, it does require a sensitive and selective laser-ionization scheme. Here we show that, under the right conditions, velocity-map imaging can be applied to the study of the inelastic scattering of OH using crossed-molecular-beam methods. We measure fully quantum-state-specified product angular distributions for OH collisions with helium and argon. The agreement between exact close-coupling quantum scattering calculations on ab initio potential energy surfaces and experimental data is generally very satisfactory, except for scattering in the most forward directions.

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

Access options

Buy this article

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

Figure 1: Schematic of the VMI setup together with the geometry of the crossed molecular beams.
Figure 2: Velocity-map images and DCSs for inelastic scattering of OH(j = 1.5f,F1) with He and Ar.
Figure 3: Three-dimensional contour plots of OH radical angular distributions.

Similar content being viewed by others

References

  1. Miller, J. A., Pilling, M. J. & Troe, J. Unravelling combustion mechanisms through a quantitative understanding of elementary reactions. Proc. Combust. Inst. 30, 43–88 (2005).

    Article  Google Scholar 

  2. Heard, D. E. & Pilling, M. J. Measurement of OH and HO2 in the troposphere. Chem. Rev. 103, 5163–5198 (2003).

    Article  CAS  Google Scholar 

  3. Ausfelder, F. & McKendrick, K. G. The dynamics of reactions of O(3P) atoms with saturated hydrocarbons and related compounds. Prog. React. Kinet. Mech. 25, 299–370 (2000).

    Article  CAS  Google Scholar 

  4. Yang, X. Multiple channel dynamics in the O(1D) reaction with alkanes. Phys. Chem. Chem. Phys. 8, 205–215 (2006).

    Article  CAS  Google Scholar 

  5. Engel, V. et al. Photodissociation of water in the first absorption band: a prototype for dissociation on a repulsive potential energy surface. J. Phys. Chem. 96, 3201–3213 (1992).

    Article  CAS  Google Scholar 

  6. Andresen, P. Classification of pump mechanisms for astronomical OH masers and a maser model for the H2O photodissociation pump mechanism. Astron. Astrophys. 154, 42–54 (1986).

    CAS  Google Scholar 

  7. Kirste, M. et al. Low-energy inelastic collisions of OH radicals with He atoms and D2 molecules. Phys. Rev. A 82, 042717 (2010).

    Article  Google Scholar 

  8. Andresen, P., Häusler, D. & Lülf, H. W. Selective Λ-doublet population of OH in inelastic collisions with H2: a possible pump mechanism for the 2Π1/2 astronomical OH maser. J. Chem. Phys. 81, 571–572 (1984).

    Article  CAS  Google Scholar 

  9. Costen, M. L., Marinakis, S. & McKendrick, K. G. Do vectors point the way to understanding energy transfer in molecular collisions? Chem. Soc. Rev. 37, 732–743 (2008).

    Article  CAS  Google Scholar 

  10. Costen, M. L. et al. Elastic depolarization of OH(A) by He and Ar: a comparative study. J. Phys. Chem. A 113, 15156–15170 (2009).

    Article  CAS  Google Scholar 

  11. Paterson, G. et al. Orientation and alignment depolarization in OH(X2Π)+Ar/He collisions. J. Chem. Phys. 129, 074304 (2008).

    Article  Google Scholar 

  12. Van Beek, M. C., Berden, G., Bethlem, H. L. & ter Meulen, J. J. Molecular reorientation in collisions of OH + Ar. Phys. Rev. Lett. 86, 4001–4004 (2001).

    Article  CAS  Google Scholar 

  13. Baba, M., Brouard, M., Rayner, S. P. & Simons, J. P. Elastic scattering dynamics of translationally and rotationally aligned molecular fragments via Doppler-resolved laser spectroscopy. OH(X2Π3/2)+Ar/He. Chem. Phys. Lett. 220, 411–416 (1994).

    Article  CAS  Google Scholar 

  14. Eppink, A. T. J. B. & Parker, D. H. Velocity map imaging of ions and electrons using electrostatic lenses: application in photoelectron and photofragment ion imaging of molecular oxygen. Rev. Sci. Instrum. 68, 3477–3484 (1997).

    Article  CAS  Google Scholar 

  15. Buijsse, B. et al. Angular distributions for photodissociation of O2 in the Herzberg continuum. J. Chem. Phys. 108, 7229–7243 (1998).

    Article  CAS  Google Scholar 

  16. Lin, J. J., Zhou, J. G., Shiu, W. C. & Liu, K. State-specific correlation of coincident product pairs in the F + CD4 reaction. Science 300, 966–969 (2003).

    Article  CAS  Google Scholar 

  17. McRaven, C., Alnis, J., Furneaux, B. & Shafer-Ray, N. A 1 + 1 ionization scheme for sensitive detection of the OH radical. J. Phys. Chem. A 107, 7138–7141 (2003).

    Article  CAS  Google Scholar 

  18. Greenslade, M. E., Lester, M. I., Radenović, D. Č., van Roij, A. J. A. & Parker, D. H. (2+1) resonance-enhanced ionization spectroscopy of a state-selected beam of OH radicals. J. Chem. Phys. 123, 074309 (2005).

    Article  Google Scholar 

  19. Hama, T. et al. Translational and internal energy distributions of methyl and hydroxyl radicals produced by 157 nm photodissociation of amorphous solid methanol. J. Chem. Phys. 131, 224512 (2009).

    Article  Google Scholar 

  20. Wang, F. Y. et al. UV photodissociation dynamics of nitric acid: the hydroxyl elimination channel. Chin. J. Chem. Phys. 22, 191 (2009).

    Article  Google Scholar 

  21. Huang, C. S., Zhang, C. M. & Yang, X. M. State-selected imaging studies of formic acid photodissociation dynamics. J. Chem. Phys. 132, 154306 (2010).

    Article  Google Scholar 

  22. Lee, H-S., McCoy, A. B., Toczyłowski, R. R. & Cybulski, S. M. Theoretical studies of the and states of the He–OH and Ne–OH complexes. J. Chem. Phys. 113, 5736–5749 (2000).

    Google Scholar 

  23. Paterson, G. et al. Orientation and alignment depolarization in OH(X2Π) + Ar/He collisions. J. Chem. Phys. 129, 074304 (2008); erratum 131, 159901 (2009).

    Article  Google Scholar 

  24. Brown, J. M. & Carrington, A. Rotational Spectroscopy of Diatomic Molecules (Cambridge Univ. Press, 2003).

    Book  Google Scholar 

  25. McBane, G. C. IMSIM program, version 2.0; available at http://faculty.gvsu.edu/mcbaneg/

  26. Dagdigian, P. J. & Alexander, M. H. Tensor cross sections and collisional depolarization of OH(X2Π) in collisions with helium. J. Chem. Phys. 130, 164315 (2009).

    Article  Google Scholar 

  27. Dagdigian, P. J. & Alexander, M. H. Tensor cross sections and the collisional evolution of state multipoles: OH(X2Π)–Ar. J. Chem. Phys. 130, 094303 (2009).

    Article  Google Scholar 

  28. Pavlovic, Z., Tscherbul, T. V., Sadeghpour, H. R., Groenenboom, G. C. & Dalgarno, A. Cold collisions of OH(2Π) molecules with He atoms in external fields. J. Phys. Chem. A 113, 14670–14680 (2009).

    Article  CAS  Google Scholar 

  29. Sawyer, B. C., Stuhl, B. K., Wang, D., Yeo, M. & Ye, J. Molecular beam collisions with a magnetically trapped target. Phys. Rev. Lett. 101, 203203 (2008).

    Article  Google Scholar 

  30. Tscherbul, T. V., Pavlovic, Z., Sadeghpour, H. R., Côté, R. & Dalgarno, A. Collisions of trapped molecules with slow beams. Phys. Rev. A 82, 022704 (2010).

    Article  Google Scholar 

  31. Dong, F., Lee, S. H. & Liu, K. Reactive excitation functions for F + p-H2/n-H2/D2 and the vibrational branching for F + HD. J. Chem. Phys. 113, 3633 (2000).

    Article  CAS  Google Scholar 

  32. Schreel, K., Schleipen, J., Eppink, A. & ter Meulen, J. J. State-to-state cross-sections for rotational-excitation of OH by collisions with He and Ar. J. Chem. Phys. 99, 8713 (1993).

    Article  CAS  Google Scholar 

  33. Yang, C. H. et al. Communication: mapping water collisions for interstellar space conditions. J. Chem. Phys. 133, 131103 (2010).

    Article  Google Scholar 

  34. Marinakis, S., Paterson, G., Kłos, J., Costen, M. L. & McKendrick, K. G. Inelastic scattering of OH(X2Π) with Ar and He: a combined polarization spectroscopy and quantum scattering study. Phys. Chem. Chem. Phys. 9, 4414–4426 (2007).

    Article  CAS  Google Scholar 

  35. Alexander, M. H., Manolopoulos, D. E., Werner, H-J. & Follmeg, B. HIBRIDON; available at http://www2.chem.umd.edu/groups/alexander/hibridon/hib43/hibhelp.html

  36. Degli Esposti, A., Berning, A. & Werner, H-J. Quantum scattering studies of the Λ doublet resolved rotational energy transfer of OH(X2Π) in collisions with He and Ar. J. Chem. Phys. 103, 2067–2082 (1995).

    Article  CAS  Google Scholar 

Download references

Acknowledgements

Research in Nijmegen was supported by the Netherlands NWO-CW project 700.58.029, the Dutch Astrochemistry Network, and the EU-ITN Network ‘ICONIC’ 238671. S. Marinakis was supported by EPSRC (UK) and the British Council–Platform Bèta Techniek Programme in Science. K.G.M. was supported by EPSRC (UK). S. Marinakis thanks S. Cybulski and J. Kłos for providing the HeOH/ArOH PES, J. Kłos for many useful discussions and suggestions, B.J. Howard (Oxford) and F.J. Aoiz (Madrid) for encouraging discussions, and the use of the Oxford Supercomputing Centre in carrying out this work.

Author information

Authors and Affiliations

Authors

Contributions

D.H.P., J.J.tM. and K.G.M. supervised the project and designed the experiments. G.S. performed the VMI experiments and collected and analysed the data with assistance from S.M., who performed the quantum calculations with assistance in interpretation from K.G.M. G.S. and D.H.P. wrote the manuscript with significant input from J.J.tM., S.M. and K.G.M.

Corresponding author

Correspondence to David H. Parker.

Ethics declarations

Competing interests

The authors declare no competing financial interests.

Supplementary information

Supplementary information

Supplementary information (PDF 819 kb)

Rights and permissions

Reprints and permissions

About this article

Cite this article

Sarma, G., Marinakis, S., ter Meulen, J. et al. Inelastic scattering of hydroxyl radicals with helium and argon by velocity-map imaging. Nature Chem 4, 985–989 (2012). https://doi.org/10.1038/nchem.1480

Download citation

  • Received:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1038/nchem.1480

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