Location of Repository

Kinetics and equilibria of ion-molecule association reactions : studied using temperature variable high pressure ion sources

By Richard Thomas Gallagher

Abstract

Interest in termolecular association reactions of the type shown below, stems from their\ud importance in the chemistry of planetary atmospheres, gas-cooled nuclear reactors and\ud gas-phase cluster ions. This study is concerned with evaluating the rate constants of such\ud X+ + X + M ------> X2+ + M k3 (1)\ud reactions as both a function of temperature and of the third body M. The values of the third\ud order rate constant k3 are expressed conventionally in terms of k3 = CT-m where T is the\ud temperature and C and m are constants characteristic of the reaction which depend also on the\ud nature of M. Literature now shows a general measure of agreement on values of C and m in\ud several studies for which X=M, however, inconsistent values have been reported on the M=He system. This thesis describes an investigation of the two systems X=N2, CO and M= the\ud reactant or a rare gas.\ud Experiments were conducted in a conventional high pressure ion source and a pulsed drift\ud ion source fitted to an updated Kratos MS9 mass spectrometer.\ud Results obtained for the one component studies show good agreement with other literature\ud values for the temperature dependence, m. In general, for both N2 and CO systems, He was\ud found to have the same efficiency as the parent molecule as a third body at 300K, but the\ud temperature dependence of k3 is markedly lower. Ar was found to behave very similarly to the\ud parent molecule in both systems. For the CO system, although good agreement is found for the\ud temperature dependence result with literature, there is still an uncertainty of about a factor of 2\ud in the room temperature values of k3

Topics: QC
OAI identifier: oai:wrap.warwick.ac.uk:4160

Suggested articles

Preview

Citations

  1. (1976). Advances in Mass Spectrometry'. doi
  2. (1970). Bohme et al,
  3. C overnight to cure. (v) The plastic covers are then removed and the samples are ground and polished to a smooth finish using carborundum paper and diamond paste.
  4. (1964). Collision Phenomena in Ionised Gases',
  5. (1978). Collision Spectroscopy', doi
  6. Communication to previous reference.
  7. (1976). Data Tables, doi
  8. (1962). Faraday Soc., doi
  9. (1982). Faraday Trans. doi
  10. (1979). Gas Phase Ion Chem. ', doi
  11. (1979). Gas Phase Ion Chemistry, doi
  12. (1979). Gas Phase Ion Chemistry', doi
  13. Ion Cyclotron Resonance Spectroscopy', doi
  14. (1973). Ion Phys.,
  15. (1983). Ion Proc.,
  16. (1975). Ion-Molecule Reactions - Their role in Radiation Chemistry', doi
  17. (1970). Kinetics of Ion-Molecule Reactions in Molecular Beams',
  18. (1983). Reactions of Small Transient Species',
  19. (1973). Schummer et al,
  20. (1973). Schummers et al,
  21. (1977). SIMION is an electrostatic lens analysis and design program originally developed by D. C. McGilvery at
  22. (1981). Soft Ionisation Biological Mass Spectrometry', doi
  23. Tandem Mass Spectrometry', doi
  24. (1983). The Mobility and Diffusion of Ions in Gases',
  25. (1941). The Theory of Rate Processes', doi
  26. Transient Species in the Gas Phase', Ed. Foutijna and Clyne. -
  27. u w ceN ý w w Li cr a- > 9 Q a = CY 0 L z a f- Q a vo M_ ýO x
  28. w Li u X cm W -116-v w t--

To submit an update or takedown request for this paper, please submit an Update/Correction/Removal Request.