On the question of ``dry'' proton motion in ionic liquids and plastic crystals

In supercooled water containing 0.01MHCl, the ionic conductivity at -32$^{o}$C is more than an order of magnitude higher than would be predicted from its fluidity. The developing tetrahedral order and the associated high vib-librational anharmonicity, permits efficient ``dry'' proton ``hopping'' transfer of protons between favorable sites. Reproducing this transport mechanism in non-aqueous (and preferably also solid) phases is a leading aim of current research. We report progress in this direction substituting water by spinning protonated cations such as NH$_{4}^{+}$ and CH$_{3}$NH$_{3}^{+}$, and anions such as HSO$_{4}^{-}$, HPO$_{3}$F$^{- }$and H$_{2}$PO$_{4}^{-}$ for the water molecules, studying both liquid and plastic crystal phases. We use pulsed field gradient NMR to distinguish proton motion from host $^{31}$P species motion, and use double quantum techniques to study $^{1}$H{\ldots}$^{31}$P separation kinetics.