Prediction and observation of a new, ground state, dipole-bound dimer anion: The mixed water/ammonia system.

Abstract

The first study of very low energy electron attachment to mixed water-ammonia clusters is reported here. A ``magic'' cluster anion distribution with strong similarities to that of pure water cluster anions is observed. The mixed (${\mathrm{H}}_{2}$O . . .${\mathrm{NH}}_{3}$${)}^{\mathrm{\ensuremath{-}}}$ dimer is created under very specific experimental conditions and its existence is a test of the theory of electron binding by a dipole. This fragile species has a very small electron binding energy as inferred from field detachment experiments.