The Polyhedral Clathrate Hydrates, Part 2. Structure of the Hydrate of Tetra <i>Iso</i>-Amyl Ammonium Fluoride

Abstract

The hydrate [i—C5H11]4N+·F—·38H2O belongs to a type of polyhedral clathrate structure in which the water molecules and the anions form the ``host'' structure and the cations are the ``guests''. The structural unit of the hydrogen-bonded clathrate cage is the H40O20 pentagonal dodecahedron. These dodecahedra are regularly associated in the crystal lattice by sharing faces, giving rise, therefore, to other polyhedra. In this hydrate, the other polyhedra are the tetrakaidecahedron and pentakaidecahedron, which form the cages enclosing the cations. A detailed three-dimensional single crystal structure analysis has been completed.