Electron-Driven Acid-Base Chemistry: Proton Transfer from Hydrogen Chloride to Ammonia

Journal Article
Science, vol. 319, iss. 5865, pp. 936-939, 2008
Authors
Soren N. Eustis, Dunja Radisic, Kit H. Bowen, Rafał A. Bachorz, Maciej Harańczyk, Gregory K. Schenter, Maciej Gutowski
Abstract
In contrast to widely familiar acid-base behavior in solution, single molecules of NH 3 and HCl do not react to form the ionic salt, NH + 4 Cl , in isolation. We applied anion photoelectron spectroscopy and ab initio theory to investigate the interaction of an excess electron with the hydrogen-bonded complex NH 3 ···HCl. Our results show that an excess electron induces this complex to form the ionic salt. We propose a mechanism that proceeds through a dipole-bound state to form the negative ion of ionic ammonium chloride, a species that can also be characterized as a deformed Rydberg radical, NH 4 , polarized by a chloride anion, Cl .
English