Carboxylic Acid-Doped SBA-15 Silica as a Host for Metallo-supramolecular Coordination Polymers
The adsorption of a metallo-supramolecular coordination polymer (Fe−MEPE) in the cylindrical pores of SBA-15 silica with pure and carboxylic acid (CA) carrying pore walls has been studied. Fe−MEPE is an intrinsically stiff polycation formed by complexation of Fe(II)−acetate with an uncharged ditopic...
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Published in | The journal of physical chemistry. B Vol. 112; no. 46; pp. 14637 - 14647 |
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Main Authors | , , , , , , , |
Format | Journal Article |
Language | English |
Published |
United States
American Chemical Society
20.11.2008
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Online Access | Get full text |
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Summary: | The adsorption of a metallo-supramolecular coordination polymer (Fe−MEPE) in the cylindrical pores of SBA-15 silica with pure and carboxylic acid (CA) carrying pore walls has been studied. Fe−MEPE is an intrinsically stiff polycation formed by complexation of Fe(II)−acetate with an uncharged ditopic bis-terpyridine ligand. The adsorption affinity and kinetics of the Fe−MEPE chains is strongly enhanced when the pore walls are doped with CA, and when the pH of the aqueous medium or temperature is increased. The initial fast uptake is connected with a decrease of pH of the aqueous solution, indicating an ion-exchange mechanism. It is followed by a slower (presumably diffusion-controlled) further uptake. The maximum adsorbed amount of Fe−MEPE in the CA-doped material corresponds to a monolayer of Fe−MEPE chains disposed side-by-side along the pore walls. The stoichiometry of Fe−MEPE in the pores (determined by XPS) was found to be independent of the loading and similar to that of the starting material. The mean chain length of Fe−MEPE before and after embedding in the CA-doped matrix was studied by solid-state 15N NMR using partially 15N-labeled Fe−MEPE. It is shown that the average chain length of Fe−MEPE is reduced when the complex is incorporated in the pores. |
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Bibliography: | istex:37EE57D549839958AE31C86B14070448CBB7C2E3 Additional figures and explanations to support the material presented in this Article. This material is available free of charge via the Internet at http://pubs.acs.org. ark:/67375/TPS-0D57BJ4G-X ObjectType-Article-1 SourceType-Scholarly Journals-1 ObjectType-Feature-2 content type line 23 |
ISSN: | 1520-6106 1520-5207 |
DOI: | 10.1021/jp804712w |