Crystalline oxyfluorinated open-framework compounds: Silicates, metal phosphates, metal fluorides and metal-organic frameworks (MOF)
| Autor: | Gerard Ferey, Thierry Loiseau |
|---|---|
| Rok vydání: | 2007 |
| Předmět: |
Coordination sphere
Chemistry Organic Chemistry Inorganic chemistry chemistry.chemical_element Microporous material Biochemistry Inorganic Chemistry Metal Trigonal bipyramidal molecular geometry Octahedron visual_art visual_art.visual_art_medium Fluorine Environmental Chemistry Hydrothermal synthesis Metal-organic framework Physical and Theoretical Chemistry |
| Zdroj: | Journal of Fluorine Chemistry. 128:413-422 |
| ISSN: | 0022-1139 |
| DOI: | 10.1016/j.jfluchem.2006.09.009 |
| Popis: | This contribution is dedicated to a short overview on the utilization of fluorine for the preparation of crystalline microporous frameworks including different families of solids: zeolites, metal phosphates and metal-organic frameworks (MOF-type). Beside the silicates compounds, this presentation is focused on the different types of fluorinated aluminum or gallium phosphates hydrothermally obtained in the presence of organic structure-directing agent or templates. The structural features of aluminum fluorides synthesized with amines are also detailed as well as the influence of fluorine in the synthesis of the metal-organic frameworks involving trivalent metals. The role of fluorine is described for the hydrothermal synthesis of the different classes of materials. Fluorine is known for playing the role of mineralizing agent and favors the formation of well crystalline phases. The use of HF modifies the pH of the reaction, which allows for the insertion of additional metallic cations on the mineral network. From the structural point of view, fluoride anions can be located within small cavities of the 3D framework and interactions with metals T (T = Si, Al, Ga, …) are often observed, resulting in the coordination change (from tetrahedral unit TO 4 to trigonal bipyramid TO 4 F or octahedron TO 4 F 2 ). Several configurations are found for fluorine and it seems to favor the stabilization of the specific cubane-like building unit (D4R), in which it is trapped, or participates to the coordination sphere of the metal atoms with bridging or terminal bondings. In general, new three-dimensional topologies with extra-large pores are obtained. The synthesis of purely aluminum fluorides with structure-directing agent is considered but only molecular or low-dimensional structures (chain-like or layered) compounds have been described. Fluorine is also used as a mineralizing agent for the preparation of well crystalline porous aluminum or chromium carboxylates and it was observed to partly substitute the aquo ligands in the giant pore of the compound MIL-100. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|
Full Text from ScienceDirect