ISSN:
0009-2940
Schlagwort(e):
Self-assembling frameworks
;
Thermal stability
;
Chemistry
;
Inorganic Chemistry
Quelle:
Wiley InterScience Backfile Collection 1832-2000
Thema:
Chemie und Pharmazie
Notizen:
Here we report on investigations that have revealed for the first time that the Cs+ ion templates the same metal germanium sulfide open-framework as (CH3)4N+ (TMA+), and that metal complexing agents enhance crystal size by at least two orders of magnitude. The synthesis, structures and thermal properties of Cs2FeGe4S10 ·× H2O and TMA2FeGe4S10 are also described. Both have 3D zinc blende-type open-framework structures. These materials have the same connectivity as TMA2MnGe4S10. The tetrahedral sites in the lattice are alternately substituted by pseudo-tetrahedral Fe2+ and adamantanoid Ge4S104- building blocks, covalently linked together by Fe(μ-S)Ge bridge bonds, to give a tetragonal unit cell. The charge-balance of the anionic framework [Fe-Ge4S10]2- is maintained by either Cs+ or TMA+ ions in the cavity spaces. Synthesis of these materials demonstrates an interesting example of a self-assembly process in which a 3D framework is built from molecular precursors. Water adsorption-desorption cycling from room temperature to 200 °C reveals framework flexibility between larger and smaller tetragonal unit cell 14 isotypes. The compound TMA2FeGe4S10 is stable in nitrogen at 350 °C and under vacuum at 450 °C. The corresponding temperatures for Cs2FeGe4S10 are 530 °C and 630°C; it is stable on cooling to room temperature under vacuum, and after subsequent exposure to air. Six hundred thirty degrees celsius is the highest recorded temperature at which the integrity of a non-oxide framework has been maintained. The framework stability and flexibility of “all-inorganic” Cs2FeGe4S10 provides an encouraging example for researchers interested in developing sulfide-based framework materials with practical applications.
Zusätzliches Material:
6 Ill.
Materialart:
Digitale Medien
URL:
http://dx.doi.org/10.1002/cber.19961290307
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