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Termolecular kinetics for the Mu+CO+M recombination reaction: A unique test of quantum rate theory

J. Chem. Phys. 125, 014307 (2006); doi:10.1063/1.2209679

Published 5 July 2006

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James J. Pan, Donald J. Arseneau, Masayoshi Senba, David M. Garner, and Donald G. Fleming
TRIUMF and Department of Chemistry, University of British Columbia, 4004 Wesbrook Mall, Vancouver, British Columbia V6T 2A3, Canada

Tiao Xie and Joel M. Bowman
Department of Chemistry, and Cherry L. Emerson Center for Scientific Computation, Emory University, Atlanta, Georgia 30322
The room-temperature termolecular rate constants, k0, for the Mu+CO+M[r harp over l]MuCO+M (M=He, N2, Ar) recombination reaction have been measured by the µSR technique, and are reported for moderator gas pressures of up to ~200  bar (densities <~0.4×1022  molec  cm–3). The experimental relaxation rates reveal an unusual signature, in being dominated by the electron spin-rotation interaction in the MuCO· radical that is formed in the addition step. In N2 moderator, k0=1.2±0.1×10–34  cm6  s–1, only about 30% higher than found in Ar or He. The experimental results are compared with theoretical calculations carried out on the Werner-Keller-Schinke (WKS) surface [Keller et al., J. Chem. Phys. 105, 4983 (1996)], within the framework of the isolated resonance model (IRM). The positions and lifetimes of resonance states are obtained by solving the complex Hamiltonian for the nonrotating MuCO system, using an L2 method, with an absorbing potential in the asymptotic region. Accurate values of the vibrational bound and resonance states of MuCO reveal unprecedented isotope effects in comparisons with HCO, due to the remarkable effect of replacing H by the very light Mu atom (mMu[approximate](1/9)mH). Due to its pronounced zero-point energy shift, there are only two (J=0) bound states in MuCO. Contributions from nonzero J states to the termolecular rate constants are evaluated through the J-shifting approximation, with rotational constants evaluated at the potential minimum. The value of the important A constant (181  cm–1) used in this approximation was supported by accurate J=K=1 calculations, from which A=180  cm–1 was obtained by numerical evaluation. The calculations presented here, with a "weak collision factor" betac=0.001, indicative of the very sparse density of MuCO states, give a very good account of both the magnitude and pressure dependence of the experimental rates, but only when the fact that the two initially bound (J=0) states become resonances for J>0 is taken into account. This is the first time in IRM calculations of atom-molecule recombination reactions where J[not-equal]0 states have proven to be so important, thus providing a truly unique test of quantum rate theory. ©2006 American Institute of Physics
History: Received 5 December 2005; accepted 9 May 2006; published 5 July 2006
Permalink: http://link.aip.org/link/?JCPSA6/125/014307/1
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KEYWORDS and PACS

Keywords
PACS
  • 82.30.Nr
    Association, addition, insertion, cluster formation (chemical reactions)
  • 82.20.Pm
    Chemical rate constants, reaction cross sections, and activation energies
  • 82.20.Hf
    Product distribution in chemical kinetics
  • 82.20.Tr
    Isotope effects in chemical kinetics including muonium
  • 82.20.Db
    Transition state theory and statistical theories of rate constants (chemical kinetics)
  • 36.10.Dr
    Positronium, muonium, muonic atoms and molecules
  • YEAR: 2006

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ISSN:
0021-9606 (print)   1089-7690 (online)
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REFERENCES (66)

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  1. D. L. Baulch, et al., J. Phys. Chem. Ref. Data 23, 847 (1994).
  2. J. A. Miller, R. J. Kee, and C. Westbrook, Annu. Rev. Phys. Chem. 41, 345 (1990).
  3. S. Cheskis, J. Chem. Phys. 102, 1851 (1995).
  4. J. M. Bowman, J. Phys. Chem. 102, 3006 (1998).
  5. M. Stumpf, A. J. Dobbyn, D. H. Mordaunt, H.-M. Keller, H. Fluethmann, R. Schinke, H.-J. Werner, and K. Yamashita, Faraday Discuss. 102, 193 (1995).
  6. R. Schinke, H.-M. Keller, M. Stumpf, and A. J. Dobbyn, J. Phys. B 28, 3081 (1995).
  7. J. M. C. Marques, J. L. Llanio-Trujillo, and A. J. C. Varandas, Phys. Chem. Chem. Phys. 2, 3583 (2000).
  8. A. F. Wagner and J. M. Bowman, J. Phys. Chem. 91, 5314 (1987).
  9. J. Qi and J. M. Bowman, J. Phys. Chem. 100, 15165 (1996);
  10. 105, 9884 (1996).
  11. H.-M. Keller, H. Floethmann, A. J. Dobbyn, R. Schinke, H.-J. Werner, C. Bauer, and P. Rosmus, J. Chem. Phys. 105, 4983 (1996).
  12. J. J. Ahumada, J. V. Michael, and D. T. Osborne, J. Chem. Phys. 57, 3736 (1972).
  13. C. J. Hochanadel, T. J. Sworski, and P. J. Ogren, J. Phys. Chem. 84, 231 (1980).
  14. R. S. Timonen, E. Ratajczak, D. Gutman, and A. F. Wagner, J. Phys. Chem. 91, 5325 (1987).
  15. H.-M. Keller and R. Schinke, J. Chem. Phys. 110, 9887 (1999).
  16. S.-W. Cho, A. F. Wagner, and B. Gazdy, J. Chem. Phys. 96, 2799 (1992);
  17. 95, 9897 (1991).
  18. H.-M. Keller, M. Stumpf, T. Schroder, C. Stock, F. Temps, R. Schinke, H.-J. Werner, C. Bauer, and P. Rosmus, J. Chem. Phys. 106, 5359 (1997).
  19. C. Stock, X. Li, H.-M. Keller, R. Schinke, and F. Temps, J. Chem. Phys. 106, 5333 (1997).
  20. H.-J. Werner, C. Bauer, P. Rosmus, H.-M. Keller, M. Stumpf, and R. Schinke, J. Chem. Phys. 102, 3593 (1995).
  21. J. D. Tobiason, J. R. Dunlop, and E. A. Rohlfing, J. Chem. Phys. 103, 1448 (1995).
  22. H. Hippler, N. Krasteva, and F. Striebel, Phys. Chem. Chem. Phys. 6, 3383 (2004).
  23. L. N. Krasnoperov, E. N. Chesnokov, H. Stark, and A. R. Ravishankara, J. Phys. Chem. A 108, 11526 (2004).
  24. L. N. Krasnoperov, Phys. Chem. Chem. Phys. 7, 2074 (2005);
  25. H. Hippler, N. Krasteva, and F. Striebel, ibid. 7, 2077 (2005).
  26. D. E. Woon, J. Chem. Phys. 105, 9921 (1996).
  27. J. M. Bowman, J. S. Bittman, and L. B. Harding, J. Chem. Phys. 85, 911 (1986).
  28. M. R. Manaa, J. Chem. Phys. 112, 8789 (2000).
  29. F. Renth, F. Temps, and A. Tröllsch, J. Chem. Phys. 118, 659 (2003).
  30. I. D. Reid, D. M. Garner, L. Y. Lee, M. Senba, D. J. Arseneau, and D. G. Fleming, J. Chem. Phys. 86, 5578 (1987).
  31. J. J. Pan, D. J. Arseneau, M. Senba, D. G. Fleming, U. Himmer, and Y. Suzuki, Phys. Chem. Chem. Phys. 2, 621 (2000).
  32. U. Himmer, H. Dilger, E. Roduner, J. J. Pan, D. J. Arseneau, D. G. Fleming, and M. Senba, J. Phys. Chem. A 103, 2076 (1999).
  33. U. Himmer and E. Roduner, Phys. Chem. Chem. Phys. 2, 339 (2000).
  34. S. Baer, D. G. Fleming, M. Senba, and A. Gonzalez, in Isotope Effects in Gas-Phase Chemistry (American Chemical Society, Washington, 1992), Chap. 11.
  35. L. Harding, J. Troe, and V. Ushakov, Phys. Chem. Chem. Phys. 2, 631 (2000);
  36. 3, 2630 (2001).
  37. J. Marques and A. Varandas, Phys. Chem. Chem. Phys. 3, 505 (2001);
  38. 3, 2632 (2001).
  39. J. L. Llanio-Trujillo, J. M. C. Marques, and A. J. C. Varandas, J. Phys. Chem. A 103, 10907 (1999).
  40. D. G. Fleming and M. Senba, in Perspectives of Meson Science (North Holland, Amsterdam, 1992), pp. 219–264.
  41. R. J. Duchovic, A. F. Wagner, R. E. Turner, D. M. Garner, and D. G. Fleming, J. Chem. Phys. 94, 2794 (1991).
  42. J. J. Pan, D. J. Arseneau, M. Senba, M. Shelley, and D. G. Fleming, Hyperfine Interact. 106, 181 (1997).
  43. D. J. Arseneau, J. J. Pan, M. Senba, M. Shelly, and D. G. Fleming, Hyperfine Interact. 106, 151 (1997).
  44. E. Roduner, Appl. Magn. Reson. 13, 1 (1997).
  45. R. E. Turner and R. F. Snider, Phys. Rev. A 58, 4431 (1998).
  46. D. G. Fleming, J. J. Pan, M. Senba, D. J. Arseneau, R. Kiefl, M. Shelley, S. F. J. Cox, P. Percival, and J.-C. Brodovitch, J. Chem. Phys. 105, 7517 (1996).
  47. F. James and M. Roos, MINUIT, CERN, 1994.
  48. J. J. Pan, M. Senba, D. J. Arseneau, J. R. Kempton, D. G. Fleming, S. Baer, A. C. Gonzalez, and R. Snooks, Phys. Rev. A 48, 1218 (1993).
  49. M. Senba, J. Phys. B 26, 3213 (1993).
  50. M. Senba, J. J. Pan, D. J. Arseneau, S. Baer, M. Shelley, R. Snooks, and D. G. Fleming, Hyperfine Interact. 87, 965 (1994).
  51. M. Senba, D. G. Fleming, D. J. Arseneau, D. M. Garner, and I. D. Reid, Phys. Rev. A 39, 3871 (1989).
  52. W. Weltner, Jr., Magnetic Atoms and Molecules (Dover, New York, 1983).
  53. M. V. Fedin, P. A. Purtov, and E. G. Bagryanskaya, J. Chem. Phys. 118, 192 (2003).
  54. F. Grein, Chem. Phys. 296, 71 (2004).
  55. B. Webster, J. Chem. Soc., Faraday Trans. 93, 205 (1997).
  56. T. A. Claxton and S. F. J. Cox, Philos. Mag. B 72, 267 (1995).
  57. J. J. Pan, D. G. Fleming, M. Senba, et al., Hyperfine Interact. 87, 865 (1994).
  58. H. Dilger, E. Roduner, M. Stolmar, I. D. Reid, D. G. Fleming, et al., Hyperfine Interact. 106, 137 (1997).
  59. R. Span, E. W. Lemmon, R. T. Jacobsen, W. Wagner, and A. Yokozeki, J. Phys. Chem. Ref. Data 29, 1361 (2000).
  60. R. B. Stewart and R. T. Jacobsen, J. Phys. Chem. Ref. Data 18, 639 (1989).
  61. CRC Handbook of Chemistry and Physics, 59th ed., edited by R. C. Weast (CRC Press, Boca Raton, 1979).
  62. B. J. Boland, J. M. Brown, A. Carrington, and A. C. Nelson, Proc. R. Soc. London, Ser. A 360, 507 (1978).
  63. H. Paul, Chem. Phys. Lett. 32, 472 (1975).
  64. The value of 3100  ns–1 given in Ref. 38 was inadvertant, and is 10× too high.
  65. S. Nordholm and A. Back, Phys. Chem. Chem. Phys. 3, 2289 (2001).
  66. J. Troe, Annu. Rev. Phys. Chem. 29, 223 (1978);
  67. J. Troe, J. Phys. Chem. 83, 114 (1978).
  68. J. Qi and J. M. Bowman, Chem. Phys. Lett. 276, 371 (1997);
  69. J. M. Bowman, J. Phys. Chem. 95, 4960 (1991).
  70. H. O. Pritchard, J. Phys. Chem. 92, 4333 (1988).
  71. D. Wang and J. M. Bowman, J. Chem. Phys. 100, 1021 (1994).
  72. D. J. Arseneau, D. G. Fleming, M. Senba, I. D. Reid, and D. M. Garner, Can. J. Chem. 66, 2018 (1988).
  73. In He, as a result of muon thermalization and charge exchange processes, only muon molecular ions (HeMu+) are observed, mainly the result of the high ionization potential (IP) of He, 24.6  eV (Refs. 35,65). Thus a trace amount (~1%) of an inert gas of IP lower than that of Mu itself (13.6  eV), either Xe or CH4, was added to produce Mu by charge exchange.

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