This paper is dedicated to Richard M. Crooks, an old friend, on the occasion of his 65 th birthday.N-methyl-4,4'-bipyridinium (Mebipy + ) can be reduced in two separate one-electron steps in 1-butyl-1-methylpyrrolidinium bis(trifluoromethylsulfonyl)imide (BMPTFSI). The first reduction product Mebipy, a radical species, is shown to have no significant interaction with dissolved CO 2 . In contrast, the second reduction product, Mebipy À , forms an adduct with CO 2 . This adduct has a relatively strong CÀ N bond from nucleophilic interaction of the non-quaternized nitrogen of the anion with the electrophilic carbon of CO 2 . These interactions are characterized using density functional theory (DFT). During electro-chemical reduction of Mebipy + in the presence of dissolved CO 2 , this strong interaction of Mebipy À drives a disproportionation reaction in which two Mebipy radicals react to produce Mebipy + and Mebipy À , which subsequently reacts with CO 2 to form the nitrogen-bound adduct, Mebipy-CO 2 À , a type of carbamate. This electrochemical DISP mechanism is simulated, providing a good fit with experimental results. The overall stoichiometry for the electrochemical capture and release of CO 2 in this system is that two electrons are required to bind one equivalent of CO 2 .[a] Dr.