Isopolyoxorhenates observed by positive ion electrospray mass spectrometry

Unravelling the complexities of inorganic and supramolecular self-assembly in solution with electrospray and cryospray mass spectrometry

“…ESI-MS has been used extensively to investigate many types of polyoxometalates including vanadates, 26 niobates, 27 tantalates, 28 chromates, 28 molybdates, 29 tungstates, [30][31][32][33] and rhenates. 34 Howarth et al investigated aqueous solutions of isopolytungstates, Fig. 1 Self-assembly of polyoxometalate clusters from {Mo 12 } 15d to the protein-sized {Mo 368 }.…”

Gas-Phase Fragmentation of Polyoxotungstate Anions

“…The advent of electrospray ionization mass spectrometry (ESI-MS) has transformed the analysis of complex inorganic ions . The technique has been used recently to analyze a range of characterized polyoxoanions, as well as complex mixtures of oxoanions (present due to pH and concentration-dependent equilibria). − The approach has now been extended to larger and more complex species and to their identification in synthetic media. − A common feature is the observation of charge reduction during the electrospray process, presumably driven by the instability of highly charged clusters due to the Coulombic repulsion in the bare clusters following desolvation. − The charge reduction commonly involves (i) ion association to form gas-phase ion clusters comprised of multiply charged polyoxoanions and available counterions or (ii) protonation of oxo ligands of the polyoxoanion cluster to form hydroxo ligands, which is often followed by a loss of water from the cluster framework. The net result of the latter process is the formal removal of O 2− from the cluster.…”