title: Contrasting ion-association behaviour of Ta and Nb polyoxometalates.
abstract: Small-angle X-ray scattering (SAXS) studies of aqueous [Ta6O19](8-) compared to prior studies of aqueous [Nb6O19](8-) reveals key differences in behaviour, which is likely at the root of the difficultly in developing polyoxotantalate chemistry. Specifically, where contact ion-pairing dominates between [Nb6O19](8-) and its counterions, solvent-separated ion-pairing between [Ta6O19](8-) and its counterions has been unveiled in the current study.
authors.affiliation: Department of Chemistry, Oregon State University, Corvallis, OR 97331, USA. may.nyman@oregonstate.edu.
authors.forename: Lauren B
authors.initials: LB
authors.lastname: Fullmer
authors.forename: Pedro I
authors.initials: PI
authors.lastname: Molina
authors.forename: Mark R
authors.initials: MR
authors.lastname: Antonio
authors.forename: May
authors.initials: M
authors.lastname: Nyman