Transition state structure of the formic acid isomeric reaction in solution

Isomeric proton transfer through a water molecule is studied using ab initio calculations. An important nuclear and electronic relaxation is obtained in the transition state structure when the solvent molecules which cause the non-specific effect are considered using the continuum model. In solution, the transition structure shows a clear ion pair nature. The validity of the separation between the chemical system and the solvent is discussed. © 1994.