Formation, distribution, and photoreaction of nano-sized vanadium oxide cluster anions

It is experimentally challenging to generate nano-sized metal oxide clusters with significant intensity as well as to resolve a single hydrogen atom by mass spectrometry (TOF-MS). Herein, the high-resolution tandem time-of-flight mass spectrometer is home-made and the experimental apparatus is capable to perform the reactivity study of nano-sized vanadium oxide clusters. The formation and distribution of nano-sized vanadium oxide cluster anions V_xO_y⁻ (x up to 70) were analyzed and the photoreaction of alkene attached complex V₄₀O₁₀₁C₂H₄⁻ (or V₄₀O₁₀₁C₃H₆⁻) was studied. Larger V_xO_y⁻ cluster anions can be generated typically under higher O₂ concentration and the intensity proportion (%) of vanadium oxide cluster with a certain oxygen-deficiency value Δ (Δ= [Formula presented] for V_xO_y⁻) in each V_x series is nearly invariant. In photoreaction of V₄₀O₁₀₁C₂H₄⁻ (or V₄₀O₁₀₁C₃H₆⁻), the transfer of two oxygen atoms from V₄₀O₁₀₁⁻ to C₂H₄ (or C₃H₆) and the generation of V₄₀O₉₉⁻ dominants the channel. The mass resolution of the primary TOF-MS for V₄₀O₁₀₁⁻ (∼1.5 nm) is up to 13002. The mass resolution of the secondary TOF-MS for photoreaction is calculated to be about 4530 to resolve parent (V₄₀O₁₀₁C₂H₄⁻) and daughter ions (V₄₀O₉₉⁻).