Low-Energy Electrons as Resonance-Controlled Cooperative Catalysts with π-Stacked Molecular Assemblies

Low-energy electrons (LEEs) offer a uniquely controllable form of redox reactivity because their chemical activity can be tuned by matching their kinetic energy to the resonant electron-capture energies of molecules. This tunable, state-selective reactivity has previously been exploited to catalyze unimolecular bond dissociation reactions; however, the potential of LEEs to mediate catalytic redox activation of molecules remains largely unexplored. Here we demonstrate that LEEs can act as cooperative catalysts with π-stacked molecular assemblies to enable CO2 activation. Resonant electron capture at a specific kinetic energy transiently converts a noncovalent pyridine dimer into a covalently interacting negative-ion state that functions as a nucleophilic catalytic intermediate. This activated dimer selectively attacks CO2, forming an anionic adduct in which CO2 is reductively activated. Subsequent transformations regenerate the pyridine dimer, establishing a closed catalytic cycle in which LEEs operate as kinetic-energy-selective redox catalysts. More broadly, this work demonstrates how resonance-controlled electron capture in weakly bound molecular assemblies can generate chemically productive transient anions, providing a physical framework linking electron-molecule scattering dynamics to chemical activation of small molecules.