Formamide hydrolysis investigated by multiple-steering ab initio molecular dynamics

The first step of formamide hydrolysis in aqueous solution has been studied coupling ab initio molecular dynamics to the multiple-steering molecular dynamics approach. We have investigated the reaction at both neutral (water addition) and alkaline (hydroxyl ion addition) pH. The activation barrier of the water-addition reaction (44 kcal mol(-1)) is much larger than that of the reaction catalyzed at alkaline pH (15 kcal mol(-1)). The solvation shell structure of the hydroxyl anion plays an important role in the dynamical and energetic properties. In particular, the free-energy profile for the hydroxyl ion addition is completely solvent induced, and its transition state properties can be essentially related to the dynamics of the hydration shell of the hydroxyl ion.