A molecular dynamics/EVB study of an S(N)2 reaction in water clusters

作者：Nelson Katherine V; Benjamin Ilan^*

来源：Chemical Physics Letters, 2010, 492(4-6): 220-225.

DOI：10.1016/j.cplett.2010.04.057

The benchmark nucleophilic substitution reaction Cl- + CH3Cl in water clusters of different sizes is studied using an empirical valence-bond model. The reaction activation-free energy, the variation in the system's electronic structure and other system properties are determined as a function of cluster size from 3 to 40 water molecules. The barrier height increases monotonically with the number of water molecules and reaches 90% of the value in bulk water with about 15 water molecules. The contribution of the water is analyzed utilizing a solvent coordinate and its coupling to the electronic state of the solute. The dynamical correction to the rate due to barrier re-crossing is small.

• 出版日期2010-6-7