Reactions of vanadium oxide cluster ions with 1,3-butadiene and isomers of butene

The gas-phase reactions of vanadium oxide cluster ions with 1,3-butadiene and the isomers of butene are examined. The correlation between the reaction products and the cluster stoichiometry, oxidation and charge-state are explored by studying the reactivity of 1,3-butadiene (C4H6) and the deuterated 1,3-butadienes C4D6 and 1,1,4,4-C4D4H2 with the clusters cations V3O6+, V3O7+, and V3O8+ and the anions VO2,3-, V2O4-6-, V3O6-9- and V4O10,11-. These studies further our understanding of the reactions of VxOy+ clusters with hydrocarbons, as reported previously [Bell, R. C.; Zemski, K. A.; Kerns, K. P.; Deng, H. T.; Castleman, Jr., A. W. J. Phys. Chem. A 1998, 102, 1733], by examining the reaction of the anions (VxOy-), deuterated butadiene species and the 2-butenes. The reactions of C4D6 and 1,1,4,4-C4D4H2 with the cluster V3O7+ demonstrate pathways for the loss of a single oxygen; oxidative dehydrogenation, and molecular association, as well as other minor products, analogous to the products previously reported for the reactions of these clusters with C4H6. The reactions of V3O7+ with the isomers of butene (1-butene, cis-2-butene and traps-2-butene) display many of the same reaction pathways that are observed for 1,3-butadiene, namely, oxidation of the hydrocarbon, oxidative dehydrogenation, and molecular association. In addition, a major channel representing the dehydrogenation of the alkene and a minor channel for C2-C3 cracking of the alkene, along with other minor products is also observed. The anionic clusters VO2,3-, V2O4,5-, V3O6-8-, and V4O10- do not react with either 1,3-butadiene or 1-butene, whereas clusters of higher oxygen content, V2O6-, V3O9-, and V4O11- display a minor reaction channel for the loss of a single oxygen atom, presumably through oxidation of the hydrocarbon and resulting in the cluster VxOy-1-.