Abstract
Symmetry induced kinetic isotope effects (SIKIE) have been observed mass spectrometrically in the termolecular association reaction of Ar and CO2+ to produce Ar-CO2+ making this the first example of SIKIE in a system where the reactants have no atoms in common. The 18O SIKIE shows a pronounced dependence on whether the CO2+ are produced directly by electron ionization or indirectly by charge transfer from Ar+. The results can be understood generally in terms of reaction restrictions based on a symmetry correlation scheme recently developed by one of the authors. This scheme indicates that CO2+ ions can have very different clustering reactivity with Ar depending on whether the ion is in an e (restricted) or an / (allowed) parity label state. Kinetic modeling of the 18O SIKIE indicates that CO2+(e)/CO2+(f)≈60 for CO2+ produced by 21 eV electron ionization.
Original language | English |
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Pages (from-to) | 177-185 |
Number of pages | 9 |
Journal | Journal of Chemical Physics |
Volume | 105 |
Issue number | 1 |
DOIs | |
State | Published - 1996 |