Uncovering an oxide ion substitution for the OH- + CH3F reaction.

Theoretical investigations on chemical reactions allow us to understand the dynamics of the possible pathways and identify new unexpected routes. Here, we develop a global analytical potential energy surface (PES) for the OH- + CH3F reaction in order to perform high-level dynamics simulations. Besides bimolecular nucleophilic substitution (SN2) and proton abstraction, our quasi-classical trajectory computations reveal a novel oxide ion substitution leading to the HF + CH3O- products. This exothermic reaction pathway occurs via the CH3OH⋯F- deep potential well of the SN2 product channel as a result of a proton abstraction from the hydroxyl group by the fluoride ion. The present detailed dynamics study of the OH- + CH3F reaction focusing on the surprising oxide ion substitution demonstrates how incomplete our knowledge is of fundamental chemical reactions.