摘要：

Laser ablation of vanadium pentoxide (V2O5) powder produces VO3, V2O5, V3O7, V3O8, and V4O10 cluster ions which have subsequently been reacted with methyl isobutyrate, methyl methacrylate monomer and its dimer in the ion cell region of a Fourier transform ion cyclotron resonance mass spectrometer. Gas phase ion/molecule chemistry has revealed that reactivity decreases with increased mass of the vanadium oxide cluster anions. VO3, V2O5, and V3O7 ions react with the three reagents, methyl isobutyrate, methyl methacrylate and its dimer, respectively, either by addition of a whole reagent molecule or an associated fragment. All products formed are a result of parallel processes. V4O10 undergoes no reaction for reaction times of up to 500 s, while V3O8 adds a water molecule. Although the ions possess a net negative charge, the reactive site toward electron rich reagents such as methyl isobutyrate, methyl methacrylate and its dimer is the under-coordinated vanadium atom. This observation is supported by the lack of reactivity toward the studied reagents by those anions (V3O8 and V4O10) whose most likely stable structures contain fully coordinated vanadium atoms.

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