Intramolecular microsolvation of SN2 transition states

Introduction of an omega-substituent (CN, Cl, or OH) onto a primary n-alkyl chloride significantly enhances the rate of S(N)2 chloride exchange in the gas phase. Trends in reactivity suggest that the rate acceleration depends primarily on through-space solvation of the transition state, especially charge-dipole interactions. The potential energy surfaces and dynamics of these reactions are discussed.