figshare
Browse
jp3c04257_si_001.pdf (4.75 MB)

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

Download (4.75 MB)
journal contribution
posted on 2023-11-09, 13:04 authored by Xiao Chen, Yuxiang Bu
Perfluoro-[n]prismanes ((C2F2)n, n = 3–8) and [n]asteranes ((C3F4)n, 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 (esol) not only changes the molecular structure but also affects the nuclear spin properties. In this work, we reveal how the esol enhances and regulates indirect nuclear spin–spin coupling between two coupled F nuclei (JFF-coupling). Results show that esol 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 esol creates a novel esol based coupling mechanism, including the newly generated through-esol (TSE) and esol-enhanced traditional through-bonds and through-space (esol-enhanced TB+TS) pathways, enhancing and regulating N(e)JFF-coupling, which crosses N bonds in the shortest TB pathway and is affected by esol. The contribution of the TSE (JTSE) is positive and increases with the increase of the central angle between two coupled F nuclei (∠F⊗F), and the contribution of the esol-enhanced TB+TS (JTB+TS) is negative and |JTB+TS| decreases with the increase of N and straight linear distance between two coupled F nuclei (dFF). Interestingly, N(e)JFF exhibits a special dependence on N/dFF and ∠F⊗F due to the cooperation and competition between JTSE and JTB+TS. When ∠F⊗F < 70°, the esol-enhanced TB+TS can play a role; JTB+TS determines sign and magnitude of N(e)JFF. When ∠F⊗F > 70°, the TSE dominates, and JTSE determines sign and magnitude of N(e)JFF. This work not only further enriches information on the states, distributions, and properties of esol but also provides insights into the nuclei spin properties in perfluorinated polyhedrons triggered by esol.

History