Aqueous speciation of polyoxometalates

Polyoxometalates self-assembly in aqueous solution is still a subject under study. This is due to the high complexity that involves describing all the chemical equilibria. Experimental techniques investigated this matter with great successes yet more efforts are needed to potentiate the applications of these metal oxides in material science (review). Last year researchers at ICIQ developed POMSimulator, which described the aqueous speciation of small molybdenum clusters.

This year the code was expanded in order to fully reproduce the aqueous speciation of not only molybdenum but also tungsten oxides. To do so, 122 metal oxides structures were optimized and their analytical frequencies calculated with ADF. The results were passed on to POMSimulator which predicted the equilibrium constants of all the polyoxometalates considered. The theoretical constants are linearly related to the experimental ones, thus suggesting that the free energies coming from ADF can be rescaled in a direct manner.

Petrus, E.; Segado, M.; Bo, C. Nucleation Mechanisms and Speciation of Metal Oxide Clusters, Chemical Science 2020, 11, 8448
Petrus, E.; Bo, C. Unlocking Phase Diagrams for Molybdenum and Tungsten Nanoclusters and Prediction of Their Formation Constants, J. Phys. Chem. A 2021, 125, 5212