Physical nature of environmental effects on intermolecular proton transfer in (O2NOH⋯NH3)(H2O)n and (ClH⋯NH3)(H2O)n (n=1–3) complexes Original Research Article

The activity of the water molecules inducing proton transfer in (O2NOH⋯NH3)(H2O)n and (ClH⋯NH3)(H2O)n (n=1–3) complexes has been analyzed within the differential product/transition state stabilization approach expressing molecular environment activity in electrostatic, exchange, delocalization, and correlation contributions. In both cases the activity is determined by two-body interactions and dominated by the multipole electrostatic term whereas other contributions constitute up to 20% and cancel each other to significant extent. In addition, the performance of the quantum mechanical/molecular mechanical method has been tested indicating the need for sufficiently accurate representation of the molecular charge distribution of the environment.