The degree of proton transfer for XH center dot center dot center dot NH3 (X = F, Br, HS, and HCOO) heterodimers upon attachment of an excess electron

A DFT method is employed to elucidate the degree of proton transfer (PT) for XH center dot center dot center dot NH3 (X = F, Br. HS, and HCOO) heterodimers upon an excess electron attachment. Only the anionic complex of (BrH center dot center dot center dot NH3)(-) has an intermolecular barrier-free proton transfer (BFPT) with a larger vertical detachment energy (VDE) of 16.60 kcal/mol. The anionic complexes without BFPT have only one (F-H center dot center dot center dot NH3- and HCOO-H center dot center dot center dot NH3-) or two minima (HS-H center dot center dot center dot NH3- and HS-NH4+) in the potential energy surfaces (PESs). In the latter case, there is a transition state with an energy barrier of 1.76 kcal/mol. When solvent is considered as the environmental conditions, intermolecular PT occurs for anionic complexes of (H2O)(n)(FH center dot center dot center dot NH3)(-) and (H2O)(n)(HCOOH center dot center dot center dot NH3)(-). The minimum number of water molecules is three for the former and two for the latter respectively. (C) 2012 Elsevier B.V. All rights reserved.