STRUCTURAL LINKS BETWEEN ZEOLITE-TYPE AND CLATHRATE HYDRATE-TYPE MATERIALS - STRANDS OF SMALL CLUSTERS OF WATER-MOLECULES INTERCONNECT OLIGOMERIC SILICATE [SI8O18(OH)2]6- ANIONS TO GENERATE THE 3D HOST STRUCTURE OF THE HETERONETWORK CLATHRATE [DMPI]6[SI8O18(OH)2].48.5H2O (DMPI = 1,1-DIMETHYLPIPERIDINIUM)

The mixed silicate-water host framework, 3infinity[{[Si8O18(OH)2]6-}2[H2O]97], of the title compound contains unprecedented and remarkable structural features, e.g. pseudo-hexagonal layer-like subunits with large circular apertures (free diameter ca. 7.9 angstrom) that resemble layer-like structural units of large-pore zeolite-type materials; the preparation and X-ray structure of the heteronetwork clathrate are reported.