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