Hydrogen-Bond Dynamics in a Protic Ionic Liquid: Evidence of Large-Angle Jumps

Abstract

We study the mol. rotation of the protic room-temp. ionic liq. ethylammonium nitrate with dielec. relaxation spectroscopy and femtosecond-IR spectroscopy (fs-IR) of the ammonium N-H vibrations. The results suggest that the rotation of ethylammonium ion takes place via large angular jumps. Such nondiffusive reorientational dynamics is unique to strongly hydrogen-bonded liqs. such as water and indicates that the intermol. interaction is highly directional in this class of ionic liqs.