Electron-transfer-coupled SN2 reaction mechanism in the gas phase

This calculation introduces a promising way to catalyze gas-phase SN2 reactions at a unimolecular level by using an excess electron (EE) as an “electron solvent”. The EE participation leads to very favorable energetics for the reaction, by neutralizing the created positive charge as the reaction proceeds, and by also positioning the transition state earlier. The reaction occurs via an unusual electron-transfer-coupled SN2 mechanism. EE-transfer from its binding zone to the attacking group is a key step. This work provides additional insights into the unimolecular SN2 mechanism catalyzed by an EE acting as an “electron solvent”.