Structural characterization of metal nanoclusters is challenging. Traditionally, nanoclusters are characterized using crystallography, which is limited to species that can be purified and crystallized. Ion mobility spectrometry (IMS) provides an opportunity to structurally characterize nanoclusters in the gas phase and obtain a qualitative understanding of subtle changes in structures that cannot be detected by other methods. IMS allows for the measurement of collisional cross sections (CCS) of individual ions by separating them based on shape, size, and charge as well as distinguishing structural isomers. Herein, we used multiplexing to improve the separation power of IMS for studying isomers of a series of polyoxovanadates (POV) with a V₆O₇ core. These POVs have applications in energy production because of the multiple, stable, and reversible electron transfer processes of the V₆O₇core. Furthermore, ligands attached to the V₆O₇ core have been shown to enhance the solubility of POV while maintaining redox activity. We use IMS to examine the position of the ligands on the POV core and provide insights into the structures of the previously unknown POV isomers. We use IMS to analyze mixtures of V₆O₇ with OEt ethoxy OEO glycol ether with species V₆O₇(OEt)_12,V₆O₇(OEt)₁₁(OEO), V₆O₇(OEt)₁₀(OEO)₂, V₆O₇(OEt)₉(OEO)₃, V₆O₇(OEt)₈(OEO)₄, V₆O₇(OEt)₇(OEO)₅, and V₆O₇(OEt)₆(OEO)₆. The experimental CCS values are compared with theoretically predicted values to provide insights into the structures of POV using Density Functional Theory calculations and IMos CCS simulator.

Solita Wilson

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