Synthesis, Characterization, and Crystal Structure of the New Clathrasil Phase Octadecasil.-A new clathrasil (silica-only porous tectosilicate) named octadecasil is prepared hydrothermally (170 • C, autoclave, 10-15 d) from aqueous silica (or aluminosilica) gels at near neutral pH in the presence of quinuclidine (Q) or Me4N+ cations as a template and F-ion as a mobilizing agent. The structure of octadecasil is closely related to that of the natural mineral zunyite and AlPO4-16. Among clathrasils, octadecasil is an exception, insofar as the all-silica framework consists of 4-and 6-membered rings only. The truncated rhombododecahedral (46612) cages and the hexahedral (46) cages are occupied by Q+ and F-ions, resp. (single crystal XRD, DTA, TG, 29Si, 13C, 19F MAS NMR data). -(CAULLET, P.; GUTH, J. L.; HAZM, J.; LAMBLIN, J. M.; GIES, H.; Eur. J. Solid State Inorg. Chem. 28 (1991) 2, 345-361; Lab. Mater. Miner., CNRS, Ec. Natl. Super. Chim. Mulhouse, Univ. Haute-Alsace, 68093 Mulhouse, Fr.; EN)

No abstract

No abstract

No abstract

No abstract