Polyhedral Clathrate Hydrates. IV. The Structure of the Tri n-Butyl Sulfonium Fluoride Hydrate

The preparation and crystal structure of (n-C4H9)3S+F—·20H2O is reported. This hydrate is isostructural with the chlorine gas hydrate, 6Cl2·46H2O, having a pseudo body-centered arrangement of H40O20 pentagonal dodecahedra in a cubic unit cell of approximately 12 Å edge. The cations occupy large voids formed by the tetrakaidecahedra in the structure and are statistically disordered. The water structure is distorted as compared with the idealized polyhedral framework and there is evidence that the pentagonal dodecahedra may be occupied by a water molecule or a fluoride ion.