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:

Quantum-induced symmetry breaking explains infrared spectra of CH5+ isotopologues

Nature Chemistry volume 2, pages 298–302 (2010)Cite this article

Subjects

Abstract

For decades, protonated methane, CH5+, has provided new surprises and challenges for both experimentalists and theoreticians. This is because of the correlated large-amplitude motion of its five protons around the carbon nucleus, which leads to so-called hydrogen scrambling and causes a fluxional molecular structure. Here, the infrared spectra of all its H/D isotopologues have been measured using the ‘Laser Induced Reactions’ technique. Their shapes are found to be extremely dissimilar and depend strongly on the level of deuteration (only CD5+ is similar to CH5+). All the spectra can be reproduced and assigned based on ab initio quantum simulations. The occupation of the topologically different sites by protons and deuterons is found to be strongly non-combinatorial and thus non-classical. This purely quantum-statistical effect implies a breaking of the classical symmetry of the site occupations induced by zero-point fluctuations, and this phenomenon is key to understanding the spectral changes studied here.

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: Important structures of protonated methane.
Figure 2: Experimental and computed IR spectra of CH5+ and of all its H/D isotopologues.
Figure 3: Disentangling the IR spectrum of the isotopologue CHD4+ in terms of all its isotopomer contributions.

Similar content being viewed by others

References

  1. Saykally, R. J. Infrared laser spectroscopy of molecular ions. Science 239, 157–161 (1988).

    Article  CAS  Google Scholar 

  2. Scuseria, G. E. The elusive signature of CH5+. Nature 366, 512–513 (1993).

    Article  Google Scholar 

  3. Boo, D. W., Liu, Z. F., Suits, A. G., Tse, J. S. & Lee, Y. T. Dynamics of carbonium ions solvated by molecular hydrogen: CH5+(H2)n (n = 1,2,3). Science 269, 57–59 (1995).

    Article  CAS  Google Scholar 

  4. Marx, D. & Parrinello, M. Structural quantum effects and three-centre two-electron bonding in CH5+. Nature 375, 216–218 (1995).

    Article  CAS  Google Scholar 

  5. White, E. T., Tang, J. & Oka, T. CH5+: The infrared spectrum observed. Science 284, 135–137 (1999).

    Article  CAS  Google Scholar 

  6. Marx, D. & Parrinello, M. CH5+: The cheshire cat smiles. Science 284, 59–61 (1999).

    Article  CAS  Google Scholar 

  7. Marx, D. & Parrinello, M. CH5+ stability and mass spectrometry (Response). Science 286, 1051a (1999); see www.sciencemag.org/cgi/content/full/286/5442/1051a.

    Article  Google Scholar 

  8. Asvany, O. et al. Understanding the infrared spectrum of bare CH5+. Science 309, 1219–1222 (2005).

    Article  CAS  Google Scholar 

  9. Borman, S. Protonated methane probed. Chem. Eng. News 83, 45–48 (2005).

    Google Scholar 

  10. Borman, S. Chemistry highlights 2005. Chem. Eng. News 83, 15–20 (2005).

    Google Scholar 

  11. Huang, X. et al. Quantum deconstruction of the infrared spectrum of CH5+. Science 311, 60–63 (2006).

    Article  CAS  Google Scholar 

  12. Olah, G. A. & Rasul, G. From Kekulé's tetravalent methane to five-, six-, and seven-coordinate protonated methanes. Acc. Chem. Res. 30, 245–250 (1997).

    Article  CAS  Google Scholar 

  13. Olah, G. A., Prakash, G. K. S. & Sommer, J. Superacids Ch. 3, 5 (Wiley, 1985).

    Google Scholar 

  14. Olah, G. A., Prakash, G. K. S., Williams, R. E., Field, L. D. & Wade, K. Hypercarbon Chemistry Ch. 1, 5, 7 (Wiley, 1987).

  15. Oka, T. Infrared spectroscopy of carbo-ions. Phil. Trans. R. Soc. Lond. A 324, 81–95 (1988).

    Article  CAS  Google Scholar 

  16. Herbst, E. Chemistry of star-forming regions. J. Phys. Chem. A 109, 4017–4029 (2005).

    Article  CAS  Google Scholar 

  17. Gerlich, D. Probing the structure of CH5+ ions and deuterated variants via collisions. Phys. Chem. Chem. Phys. 7, 1583–1591 (2005).

    Article  CAS  Google Scholar 

  18. Kumar, P. P. & Marx, D. Understanding hydrogen scrambling and infrared spectrum of bare CH5+ based on ab initio simulations. Phys. Chem. Chem. Phys. 8, 573–586 (2006).

    Article  Google Scholar 

  19. Schlemmer, S., Lescop, E., von Richthofen, J., Gerlich, D. & Smith, M. A. Laser induced reactions in a 22-pole ion trap: C2H2+ + hν3 + H2 → C2H3+ + H. J. Chem. Phys. 117, 2068–2075 (2002).

    Article  CAS  Google Scholar 

  20. Schlemmer, S. & Asvany, O. Laser induced reactions in a 22-pole ion trap. J. Phys.: Conf. Series 4, 134–141 (2005).

    CAS  Google Scholar 

  21. Marx, D. & Hutter, J. Ab Initio Molecular Dynamics: Basic Theory and Advanced Methods (Cambridge Univ. Press, 2009).

    Book  Google Scholar 

  22. Wilson, E. B. Jr, Decius, J. C. & Cross, P. C. Molecular Vibrations: The Theory of Infrared and Raman Vibrational Spectra (McGraw-Hill, 1955).

    Google Scholar 

  23. Wolfsberg, M. Isotope effects. Annu. Rev. Phys. Chem. 20, 449–478 (1969).

    Article  CAS  Google Scholar 

  24. Dyczmons, V. & Kutzelnigg, W. Ab initio calculations of small hydrides including electron correlation XII. The ions CH5+ and CH5−. Theoret. Chim. Acta (Berlin) 33, 239–247 (1974).

    Article  CAS  Google Scholar 

  25. Schreiner, P. R., Kim, S.-J., Schaefer, H. F. III & von Ragué Schleyer, P. CH5+: The never-ending story or the final word? J. Chem. Phys. 99, 3716–3720 (1993).

    Article  CAS  Google Scholar 

  26. Marx, D. & Savin, A. Topological bifurcation analysis: Electronic structure of CH5+. Angew. Chem. Int. Ed. Engl. 36, 2077–2080 (1997).

    Article  CAS  Google Scholar 

  27. Müller, H., Kutzelnigg, W., Noga, J. & Klopper, W. CH5+: The story goes on. An explicitly correlated coupled-cluster study. J. Chem. Phys. 106, 1863–1869 (1997).

    Article  Google Scholar 

  28. Deskevich, M. P., McCoy, A. B., Hutson, J. M. & Nesbitt, D. J. Large-amplitude quantum mechanics in polyatomic hydrides. II. A particle-on-a-sphere model for XHn (n = 4,5). J. Chem. Phys. 128, 094306 (2008).

    Article  Google Scholar 

  29. McCoy, A. B. et al. Ab initio diffusion Monte Carlo calculations of the quantum behavior of CH5+ in full dimensionality. J. Phys. Chem. A 108, 4991–4994 (2004).

    Article  CAS  Google Scholar 

  30. Huang, X., Johnson, L. M., Bowman, J. M. & McCoy, A. B. Deuteration effects on the structure and infrared spectrum of CH5+. J. Am. Chem. Soc. 128, 3478–3479 (2006).

    Article  CAS  Google Scholar 

  31. Johnson, L. M. & McCoy, A. B. Evolution of structure in CH5+ and its deuterated analogues. J. Phys. Chem. A 110, 8213–8220 (2006).

    Article  CAS  Google Scholar 

  32. Asvany, O. et al. High-resolution rotational spectroscopy in a cold ion trap: H2D+ and D2H+. Phys. Rev. Lett. 100, 233004 (2008).

    Article  Google Scholar 

  33. Oepts, D., van der Meer, A. F. G. & van Amersfoort, P. W. The free-electron-laser user facility Felix . Infrared Phys. Technol. 36, 297–308 (1995).

    Article  CAS  Google Scholar 

  34. Marx, D. & Hutter, J. Modern Methods and Algorithms of Quantum Chemistry (ed. Grotendorst, J.) 301–449 (NIC, FZ Jülich, 2000).

  35. Hutter, J. et al. CPMD Software Package, see www.cpmd.org.

Download references

Acknowledgements

The Bochum group is grateful to H. Forbert for useful discussions and technical help and is supported by Deutsche Forschungsgemeinschaft (DFG) (Normalverfahren MA 1547/4) and Fonds der Chemischen Industrie (FCI) (Chemiefonds–Stipendium to A.W. and general grant to D.M.). The simulations were carried out at HLRB II (München), Bovilab@RUB (Bochum) and Rechnerverbund–NRW (Dortmund). The Köln group gratefully acknowledges the help of their mechanical workshop (J. Krause, D. Moratschke and their team) as well as FOM for providing beam time. The skilful assistance provided by the Felix staff is greatly appreciated. Financial support by DFG through SFB 494 and the European QUASAAR network and the Initiative ‘Integrating Activity on Synchrotron and Free Electron Laser Science’ is also acknowledged.

Author information

Author notes

  1. Gerald Mathias

    Present address: Present address: Lehrstuhl für BioMolekulare Optik, Ludwig–Maximilians–Universität, Oettingenstrasse 67, 80538 München, Germany,

  2. Sergei D. Ivanov and Oskar Asvany: These authors contributed equally to this work

Authors and Affiliations

  1. Lehrstuhl für Theoretische Chemie, Ruhr-Universität Bochum, Bochum, 44780, Germany

    Sergei D. Ivanov, Alexander Witt, Gerald Mathias & Dominik Marx

  2. I. Physikalisches Institut, Universität zu Köln, Zülpicher Strasse 77, Köln, 50937, Germany

    Oskar Asvany, Edouard Hugo & Stephan Schlemmer

  3. Felix Facility, FOM–Institute for Plasma Physics ‘Rijnhuizen’, Nieuwegein, 3430 BE, The Netherlands

    Britta Redlich

Authors
  1. Sergei D. Ivanov
    View author publications

    You can also search for this author in PubMed Google Scholar

  2. Oskar Asvany
    View author publications

    You can also search for this author in PubMed Google Scholar

  3. Alexander Witt
    View author publications

    You can also search for this author in PubMed Google Scholar

  4. Edouard Hugo
    View author publications

    You can also search for this author in PubMed Google Scholar

  5. Gerald Mathias
    View author publications

    You can also search for this author in PubMed Google Scholar

  6. Britta Redlich
    View author publications

    You can also search for this author in PubMed Google Scholar

  7. Dominik Marx
    View author publications

    You can also search for this author in PubMed Google Scholar

  8. Stephan Schlemmer
    View author publications

    You can also search for this author in PubMed Google Scholar

Contributions

D.M. and S.S. designed the research. O.A., E.H., B.R. and S.S. performed the experiments. S.D.I. and A.W. performed the calculations. S.D.I., O.A., A.W., G.M., D.M. and S.S. analysed the data. S.D.I., O.A., A.W., D.M. and S.S. wrote the paper.

Corresponding authors

Correspondence to Sergei D. Ivanov or Oskar Asvany.

Ethics declarations

Competing interests

The authors declare no competing financial interests.

Supplementary information

Supplementary information

Supplementary information (PDF 1542 kb)

Rights and permissions

Reprints and permissions

About this article

Cite this article

Ivanov, S., Asvany, O., Witt, A. et al. Quantum-induced symmetry breaking explains infrared spectra of CH5+ isotopologues. Nature Chem 2, 298–302 (2010). https://doi.org/10.1038/nchem.574

Download citation

  • Received:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1038/nchem.574

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