title: Direct 2H NMR observation of the proton mobility of the acidic sites of anhydrous 12-tungstophosphoric acid.
abstract: Flip and hop before you're caught! The proton dynamics of solid 12-tungstophosphoric acid (TPA) is probed by solid-state (2)H NMR in a temperature range from 293-503 K. Protons of TPA are shown to be involved in two types of molecular motion (see picture): the anisotropic local two-site flipping between the two possible orientations of the O-H bond at bridged oxygens of the Keggin anion, and the isotropic diffusion by hopping between neighboring surface oxygens of the anion.
authors.affiliation: Boreskov Institute of Catalysis, Siberian Branch of the Russian Academy of Sciences, Prospekt Akademika Lavrentieva 5, Novosibirsk 630090, Russia. kdi@catalysis.ru
authors.forename: Daniil I
authors.initials: DI
authors.lastname: Kolokolov
authors.forename: Maxim S
authors.initials: MS
authors.lastname: Kazantsev
authors.forename: Mikhail V
authors.initials: MV
authors.lastname: Luzgin
authors.forename: Hervé
authors.initials: H
authors.lastname: Jobic
authors.forename: Alexander G
authors.initials: AG
authors.lastname: Stepanov