Direct capture of a low-energy free-electron into delocalized σ orbitals for enabling state- and bond-selective reactions.

Chemically activating a bond by capturing a low-energy free-electron directly and resonantly into its σ orbital is conceptually simple and yet the most fascinating possibility for achieving state-specific and bond-specific chemical control. But this direct approach has not been explored experimentally due to the very low resonant electron capture cross-section of electrons into the σ orbital. Here we report defunctionalization and dehydrogenation reactions that are bond-selectively enabled by the direct capture of a low-energy electron into the σ orbital. The remarkable efficiency of these reactions can be attributed to superpositions of the σ orbital with its vicinal or conjugated orbitals. The ubiquity of such quantum superpositions in molecules opens unprecedented experimental possibilities in the aspiration to control chemical reactions using low-energy free-electrons.