A Self-assembled Fluoride-Water Cyclic Cluster of $[F(H_2O)]_4^{4-}$ in a Molecular Box

摘要

We present an unprecedented fluoride-water cyclic cluster of$[F(H_2O)]_4^{4-}$ assembled in a cuboid-shaped molecular box formed by twolarge macrocycles. Structural characterization reveals that the$[F(H_2O)]_4^{4-}$ is assembled by strong H-bonding interactions (OH...F =2.684(3) to 2.724(3) {\AA}), where a fluoride anion plays the topological roleof a water molecule in the classical cyclic water octamer. The interaction offluoride was further confirmed by $^{19}$F NMR and $^1$H NMR spectroscopies,indicating the encapsulation of the anionic species within the cavity insolution. High level DFT calculations and Bader topological analyses fullysupport the crystallographic results, demonstrating that the bondingarrangement in the fluoride-water cluster arises from the unique geometry ofthe host.