Unravelling the complexities of polyoxometalates in solution using mass spectrometry: Protonation versus heteroatom inclusion

A route to unravel and the complexities of polyoxometalates in solution using electrospray mass spectrometry is presented. This reveals the limited speciation of the clusters in organic solvent compared to that in aqueous solution and allows the unambiguous assignment of the protonation states of the cluster as a function of heteroatom inclusion.