Effect of heterometal‐functionalization and template exchange on the redox chemistry of molecular vanadium oxides

Abstract

The substitution effect: Electrochemical structure‐property relationships are reported for a metal‐functionalized dodecavanadate cluster. To this end, the effects of heterometal substitution and template exchange on the redox properties are studied. The type of heterometal and the resulting structural distortion of the cluster shell are main factors controlling the cluster properties, while the redox potentials correlate with the overall cluster charge. Exchange of the template anion from chloride to bromide shows no major effect. Polyoxometalates (POMs) have emerged as material of interest in many applications such as energy storage and conversion due to their redox activity and molecularly defined structure. However, especially for polyoxovanadates a lack of understanding between structural modifications and physicochemical properties remains. The present study leverages a lacunary dodecavanadate to systematically investigate the electronic effect of heterometal functionalization. While structural distortion affects the stability of the cluster, the redox potentials correlate with the overall cluster charge. Furthermore, we report the first bromide‐templated analogue of this cluster family. While the halide anion is crucial for the formation of the cluster, no major effect on the electrochemical properties is observed. By improving the understanding of structure‐property relationship in this work, we hope to enable a more predictable tuning of redox‐properties of polyoxovandates.