24203-25-6Relevant articles and documents
Translational energy dependence of reaction mechanism: Xe+ + CH4->XeH+ + CH3
Miller, G. D.,Strattan, L. W.,Cole, C. L.,Hierl, P. M.
, p. 5082 - 5092 (1981)
The dynamics of the exoergic ion-molecule reaction Xe+(CH4,CH3)XeH+ were studied by chemical accelerator techniques over the relative translational energy range 0.2 to 8 eV.Results of the kinematic measurements are reported as scattering intensity contour maps in Cartesian velocity space.Center-of-mass angular and energy distributions, derived from these maps, provide information on the reaction mechanism and on the partitioning of available energy between internal and translational modes in the products.The results suggest that reaction proceeds via the formation of a long-lived complex at low collision energies (below 0.5 eV) and by a direct mechanism approaching spectator stripping at higher energies.
Brincourt, G.,Pacha, S. Rajab,Catella, R.,Zerega, Y.,Andre, J.
, p. 573 - 577 (1989)
The decay dynamics of photoexcited rare gas cluster ions
Jones,Jukes,Stace
, p. 959 - 968 (2007/10/03)
The kinetic energies of fast neutrals ejected from photoexcited rare gas cluster ions have been measured for the following systems: Arn+, Krn+, Xen+ at two photon wavelengths: 355 and 532 nm, and for n in the range 2-19. New data are presented for xenon at both wavelengths, and for argon and krypton cluster ions at 355 nm. For argon and krypton cluster ions at 532 nm, new data have been recorded which are more accurate than those presented previously. A Monte Carlo model of the experiment has been used to simulate the kinetic energy releases and also to investigate variations in the scattering anisotropy parameter (β) as a function of photon energy and cluster composition and size. Significant fluctuations in β are observed, and these are attributed to a combination of structural variation and changes to the nature of the central chromophore. For small cluster ions the kinetic energy release data show evidence of being influenced by the final spin-orbit state of the atomic ion. Overall, there is a gradual decline in kinetic energy release as a function of increasing cluster size; however, there are marked variations within this trend. For all three rare gas systems the results show that the primary response to photoexcitation is the ejection of a single atom with a high kinetic energy on a time scale that is short compared with the rotational period of a cluster.
Absolute cross sections for electron-impact ionization and dissociative ionization of the SiF free radical
Hayes, Todd R.,Wetzel, Robert C.,Baiocchi, Frank A.,Freund, Robert S.
, p. 823 - 829 (2007/10/02)
Absolute cross sections for electron-impact ionization of the SiF free radical from threshold to 200 eV are presented for formation of the parent SiF+ ion and the fragment Si+ and F+ ions.A fast beam of SiF is prepared by charge transfer neutralization of an SiF+ beam.The radicals form in the ground electronic state and predominantly in their ground vibrational state, as shown by agreement of the measured ionization threshold with the ionization potential.The absolute cross section for SiF -> SiF+ at 70 eV is 3.90 +/- 0.32 Angstroem2.The ratio of cross sections for formation of Si+ to that for SiF+ at 70 eV is 0.528 +/- 0.024; the ratio for formation of F+ to that of SiF+ is 0.060 +/- 0.008.The observed threshold energy for Si+ formation indicates the importance of ion pair formation SiF -> Si+ + F-.Breaks in the cross section at 14.3 and 17 eV are assigned as dissociative ionization thresholds.
