Enhanced J-Couplings through Specially Solvated Electron in Perfluoro-[n]Prismanes and [n]Asteranes

Perfluoro-[n]prismanes ((C₂F₂), n = 3-8) and [n]asteranes ((C₃F₄), n = 3-5) exhibit a strong perfluoro cage effect that can stably encapsulate an additional electron inside the cage. The 2s-like distribution of solvated electron (e_sol^-) not only changes the molecular structure but also affects the nuclear spin properties. In this work, we reveal how the e_sol^- enhances and regulates indirect nuclear spin-spin coupling between two coupled F nuclei (J_FF-coupling). Results show that e_sol^- is mainly distributed in the central cavity, and a part of it penetrates into the C-shell and C-F bond regions due to the unique polyhedral C-shell structure. Such a 2s-like e_sol^- creates a novel e_sol^- based coupling mechanism, including the newly generated through-e_sol^- (TSE) and e_sol^--enhanced traditional through-bonds and through-space (e_sol^--enhanced TB+TS) pathways, enhancing and regulating J_FF-coupling, which crosses N bonds in the shortest TB pathway and is affected by e_sol^-. The contribution of the TSE (J_TSE) is positive and increases with the increase of the central angle between two coupled F nuclei (∠F⊗F), and the contribution of the e_sol^--enhanced TB+TS (J_TB+TS) is negative and |J_TB+TS| decreases with the increase of N and straight linear distance between two coupled F nuclei (d_FF). Interestingly, J_FF exhibits a special dependence on N/d_FF and ∠F⊗F due to the cooperation and competition between J_TSE and J_TB+TS. When ∠F⊗F < 70°, the e_sol^--enhanced TB+TS can play a role; J_TB+TS determines sign and magnitude of J_FF. When ∠F⊗F > 70°, the TSE dominates, and J_TSE determines sign and magnitude of J_FF. This work not only further enriches information on the states, distributions, and properties of e_sol^- but also provides insights into the nuclei spin properties in perfluorinated polyhedrons triggered by e_sol^-.