| Autor: |
Mair, C., Herman, Z., Fedor, J., Lezius, M., Märk, T. D. |
| Předmět: |
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| Zdroj: |
Journal of Chemical Physics; 1/15/2003, Vol. 118 Issue 3, p1479, 8p, 1 Chart, 8 Graphs |
| Abstrakt: |
Dissociations and reactions induced by impact of acetonitrile monomer ions (CH[sub 3]CN[sup +], CD[sub 3]CN[sup +]), dimer ions [(CH[sub 3]CN)[sub 2, sup +], (CD[sub 3]CN)[sub 2, sup +]] and trimer ions [(CD[sub 3]CN)[sub 3, sup +]] on a hydrocarbon-covered stainless-steel surface were investigated over the projectile energy range of 3-70 eV. Both simple dissociations of the projectile ion and chemical reactions of H-atom transfer from the surface material (followed by dissociations of the protonated projectile ion formed) were observed for the monomer ions. Results obtained for the dimer ions (CD[sub 3]CN)[sub 2, sup +] indicate the formation of the protonated acetonitrile ions via surface-induced reactions in two ways: (i) an intracluster ionmolecule reaction followed by dissociation to form CD[sub 3]CND[sup +], and (b) a hydrogen pick-up reaction from the surface material during the interaction of the dimer ion with the surface leading to CD[sub 3]CNH[sup +]. A simple model based on the Brauman double-well potential—suggested earlier to explain the occurrence of analogous reactions in acetone cluster ion/surface interactions—accounts well for the formation of both product ions. Moreover, in adition to these protonated species, considerable amounts of nondissociated dimer ions were observed after acetonitrile dimer cation/ surface collisions with energies up to 25 eV. Similarly, both trimer ions (up to 20 eV) and dimer ions (up to 30 eV) were observed in acetonitrile trimer cation/surface interactions. This indicates that unimolecular dissociation kinetics governs the product formation for these cluster ion/surface interactions. [ABSTRACT FROM AUTHOR] |
| Databáze: |
Complementary Index |
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