New isopolyoxovanadate ions identified by electrospray mass spectrometry

Characterization of isopoly metal oxyanions using electrospray time-of-flight mass spectrometry

“…The spectra observed for vanadate solutions here differ from results of another study published recently; 12 that study reported the detection of a large number of previously unreported vanadate species. Since most of the potentials used for the electrospray mass spectrometer to obtain these spectra were not reported, it is difficult to conclude whether the species detected are in fact present in solution or simply due to fragments caused by the electrospray process.…”

“…Tungstate forms four different species in aqueous solution depending on the pH and the concentration of the solution; 9 in dilute solutions the two major species are the monomer in basic solutions, [WO 4 ] 2 , and the dodecamer, [W 12 O 39 ] 6 , in acidic solutions. Two other species tend to form at higher concentrations and at neutral to slightly acidic pH values.…”

“…4(b). The most prominent peak is at m/z 1426.09, and there is a cluster about 9 u lower corresponding to loss of water, [H 4 W 12 O 39 ] 2 , and two clusters 9 and 18 u higher which correspond to the addition of one and two water molecules, [H 8 W 12 O 41 ] 2 and [H 10 W 12 O 42 ] 2 , respectively.…”

Reaction Dynamics and Solution Chemistry of Polyoxometalates by Electrospray Ionization Mass Spectrometry

“…Truebenbach et al [29] investigated basic and acidic solutions of V V and W VI by ESI-TOF-MS. In particular, their observations differed from those of Walanda et al [22] in terms of species observed for V V solutions. The authors suggested that this discrepancy was due to fragmentation in the latter study.…”

“…The potential of ESI-MS to resolve aqueous speciation was investigated early on. A comprehensive series of studies was carried out by von Nagy-Felsobuki and co-workers, who investigated the solution chemistry of V, [22,23] W, [24] Mo, [25] Cr, [26] Nb, and Ta polyoxo ions by ESI-MS. [27] In all cases they observed signals which were assigned to new species that have not been reported by other methods. While the only homoleptic isopolyoxoniobates that have been unambigiously characterized to date are [Nb 6 O 19 ] 8À , [Nb 10 O 28 ] 6À , and [Nb 20 O 54 ] 8À , [28] the authors also observed species with 4, Figure 5.…”