Stability of Cu(II)− and Fe(III)−Porphyrins on Montmorillonite Clay: An X-ray Absorption Study
Autor: | Kathleen A. Carrado, S. R. Wasserman |
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Rok vydání: | 1996 |
Předmět: | |
Zdroj: | Chemistry of Materials. 8:219-225 |
ISSN: | 1520-5002 0897-4756 |
DOI: | 10.1021/cm950330w |
Popis: | The Cu(II) and Fe(III) complexes of water-soluble tetrakis(N,N,N-trimethylanilinium)porphyrin (TTAP) and tetrakis(N-methylpyridyl)porphyrin (TMPyP) were placed within the interlayers of Ca(II)−montmorillonite through ion exchange. The free base forms of the porphyrins were also added to samples of Cu(II)− and Fe(III)−montmorillonites. X-ray absorption spectroscopy (XAS), both X-ray absorption near-edge structure (XANES) and extended X-ray absorption fine structure (EXAFS), were used to monitor the fate of the metal ions. The Cu(II)−metalloporphyrins do not demetalate upon contact with the acidic montmorillonite support. The XAS data also suggest that Fe(III)−porphyrin complexes are stable on smectite supports. XANES data demonstrate that the free base porphyrin TTAP metalates on the surface of a Cu(II)-exchanged clay to form a stable Cu(II)−porphyrin-clay complex. |
Databáze: | OpenAIRE |
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