ISSN:
1572-8862
Schlagwort(e):
Clusters
;
vanadium oxide
;
size dependence
;
gas phase
;
reactivities
Quelle:
Springer Online Journal Archives 1860-2000
Thema:
Maschinenbau
,
Physik
Notizen:
Abstract This article is intended to summarize recent studies on the reactivity and dynamics of gas-phase vanadium oxide cluster cations in terms of their dependence on the size and stoichiometry of the selected clusters. In addition, the effects of coordination, oxidation states of the vanadium atoms, influence of charge, and ionization potentials on the reactivity of these clusters are presented. Reactions of the clusters V3 O 7 + and V5 O 12 + with 1-butene, 1,3-butadiene, and difluoromethane differ significantly from those of similar clusters such as V3 O 6 + and V5 O 11 + . While oxygen transfer and carbon–carbon cracking reactions are observed for the former clusters, the latter primarily associate the neutral reactant species. These differences are largely related to the oxidation states of the vanadium atoms within the cluster, but also display a dependence on the size of the cluster, with the smaller clusters being more reactive than the larger ones. Reactions with carbon tetrachloride display a dependence on the coordination of the clusters, but also display a distinct change in reaction channels from the chloride transfer reaction for the smaller clusters to the oxidative chloride transfer and formation of neutral phosgene for cluster with more than three vanadium atoms. In contrast, the dehydrohalogenation reactions of CH3CF3 display little dependence on the size of the clusters.
Materialart:
Digitale Medien
URL:
http://dx.doi.org/10.1023/A:1021952907867
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