AQUEOUS COORDINATION CHEMISTRY USING ELECTROSPRAY MASS-SPECTROMETRY OF ANIONS - METAL(VI)-MONOSACCHARIDE COMPLEXES (M = W OR MO)

Electrospray mass spectrometry has been applied for the first time to the co-ordination chemistry of aqueous anions, using as a model system the reaction of tungstate or molybdate with galactaric (mucic) acid a nd galacturonic acid; 1 : 1, 2: 1 and 1 :2 complexes are found, thus c onfirming and extending previous solution-state studies. The gas-phase ions may undergo minor dehydration, and some decarboxylation. Neverth eless, the method is shown to provide a rapid and simple means for ide ntifying mixtures of anionic complexes in dilute aqueous solution, eve n when their binding constants are modest.