APPLICATION OF ELECTROSPRAY-IONIZATION MASS-SPECTROMETRY TO THE STUDYOF DILUTE AQUEOUS OLIGOMERIC ANIONS AND THEIR REACTIONS

For the first time, electrospray ionisation mass spectrometry has been carried out on purely aqueous solutions of anions, specifically dilut e (10(-3) mol dm(-3) isopolytungstates, peroxotungstates and heteropol ymolybdates and tungstates. Many new species have been detected that h ave not previously been reported in water, including [W6O19](2-) and [ W2O7](2-). To demonstrate its investigative potential, the method was used to identify the complex and previously uncharacterised reaction p roducts from the reaction of H2O2 on powdered tungsten metal, where he xametalates form with up to four peroxo ligands, and also to track kin etic processes such as the course of metal-ion exchange between phosph ododecametalates, and the attack of H2O2 on paratungstate B.