Steering polyoxometalate transformation from octahedral to tetrahedral coordination by counter-cations

Abstract

Polyoxometalates (POMs) are intriguing catalysts for various reactions. However, the function of their counter-cations is overlooked. Here, we show that flexible counter-cations of methyltrioctylammonium can trigger polyoxovanadates to transform from octahedrally coordinated H₂V₁₀O₂₈⁴⁻ to tetrahedrally coordinated V₁₀O₂₆²⁻. This structural transformation enhances the performance tunability of POM chemistry and improves catalyst design.