Bitte benutzen Sie diese Referenz, um auf diese Ressource zu verweisen:
doi:10.22028/D291-23946
Titel: | Structural links beetween zeolite-type and clathrate hydrate-type materials synthesis and crystal structure of [NMe4]16[Si8O20][OH]8.116H2O |
VerfasserIn: | Wiebcke, Michael Hoebbel, Dagobert |
Sprache: | Englisch |
Erscheinungsjahr: | 1992 |
Quelle: | Journal of the Chemical Society / Dalton transactions. - 1992, 1, S. 2451-2455 |
Kontrollierte Schlagwörter: | Hydroxide Fraktionierte Kristallisation Kristallisation Kristallstruktur |
DDC-Sachgruppe: | 540 Chemie |
Dokumenttyp: | Journalartikel / Zeitschriftenartikel |
Abstract: | A novel crystalline tetramethylammonium silicate hydroxide polyhydrate has been obtained by fractional crystallization at room temperature from a highly alkaline aqueous NMe4OH-SiO2 solution. X-Ray single-crystal studies at 200 K revealed the trigonal crystal system, the unit-cell constants (hexagonal setting) a = 18.126(2) and c = 57.529(9) A°, the space group R3 and Z = 3 formula units of [NMe4]16[Si8O20][OH] 8·116H2O per unit cell. The crystal structure has been determined from 1416 unique Mo-Ka¯ data and refined to R = 0.104. The host-guest compound is of polyhedral clathrate type with a mixed three-dimensional, (mainly) four-connected tetrahedral network composed of oligomeric silicate anions [Si8O20]8-, OH- ions and H2O molecules linked via hydrogen bonds O-H?O. The silicate anions are each built up of eight SiO4 tetrahedra sharing corners to form a cube (double four-ring structure). Cationic guest species NMe4+ are enclosed in large polyhedral cavities [4668], [425865], [51264] and [425867] of the host structure; small [46] cages (i.e. the double-ring anions) and [4356] cages are unoccupied. Each silicate anion is the centre of a specific and probably very stable finite cluster [(NMe4)6(Si8O20)·24H 2O]2-. It is suggested that the polyhydrate may be taken as a crystalline model system for studies on the structures of aqueous tetramethylammonium silicate solutions. |
Link zu diesem Datensatz: | urn:nbn:de:bsz:291-scidok-19518 hdl:20.500.11880/24002 http://dx.doi.org/10.22028/D291-23946 |
Datum des Eintrags: | 22-Dez-2008 |
Fakultät: | SE - Sonstige Einrichtungen |
Fachrichtung: | SE - INM Leibniz-Institut für Neue Materialien |
Sammlung: | INM SciDok - Der Wissenschaftsserver der Universität des Saarlandes |
Dateien zu diesem Datensatz:
Datei | Beschreibung | Größe | Format | |
---|---|---|---|---|
hoeb199205.pdf | 700,12 kB | Adobe PDF | Öffnen/Anzeigen |
Alle Ressourcen in diesem Repository sind urheberrechtlich geschützt.