Water effect on the bond dissociation energy of O-H and N-H bonds in phenol and aniline: The testing of simple molecular dynamics model

A chemical microsolvation model for solution phase bond dissociation enthalpy (BDE) evaluation by means of molecular dynamics is presented. In this simple model, the primary solvent effect on the BDE values was estimated by placing of five water molecules nearby the studied functional groups evenly. Furthermore, the secondary solvent effect was reflected using the conductor like screening model (COSMO). From the quantum-chemical point of view, the molecular dynamics simulations based on the B3LYP functional in rather small basis set were performed. Despite of the constitutional limitations of the proposed model, the obtained O-H and N-H BDE values in phenol (363 kJ mol(-1)) and aniline (369 kJ mol(-1)) are in good agreement with the experimental solution phase data.