Microhydration Effects on the Intermediates of the S_N2 Reaction of Iodide Anion with Methyl Iodide

摘要

Reactions of halide anions with methyl halides X~-+CH3Y→ XCH3+Y~- are bimolecular nucleophilic substitution (S_N2) reactions that have been well investigated in the last few decades. Figure 1 shows the typical potential energy surfa- ces (PES) proposed for symmetric X~-+CH3X→XCH3+X~-S_N2 reactions along the reaction coordinate. In the gas phase, the PES has two minima, which correspond to the stable X~-(CH3X) complexes. The PES is substantially distorted by solvation.