Luminescence of europium and cerium ([Eu.cntnd.2.2.1]3+ and [Ce.cntnd.2.2.1]3+) cryptates adsorbed on oxide surfaces
| Autor: | N. Sabbatini, M. F. Hazenkamp, G. Blasse |
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| Rok vydání: | 1991 |
| Předmět: | |
| Zdroj: | The Journal of Physical Chemistry. 95:783-787 |
| ISSN: | 1541-5740 0022-3654 |
| DOI: | 10.1021/j100155a055 |
| Popis: | The luminescence properties of the (Eu{contained in}2.2.1){sup 3+} and (Ce{contained in}2.2.1){sup 3+} cryptates adsorbed on SiO{sub 2} and TiO{sub 2} surfaces are reported. There are considerable changes in the excitation and emission spectra of the luminescence of the Eu{sup 3+} cryptate compared to those of the complex in aqueous solution. this suggest that H{sub 2}O molecules in the first coordination sphere of the Eu{sup 3+} ion are replaced by Si-O entities. From the long decay time of this complex on silica it follows that there are no H{sub 2}O molecules coordinating the Eu{sup 3+} ion anymore. This suggests that the cryptate molecule has a specific, hemispherical, conformation on this surface. Evidence is given that the (Eu{contained in}2.2.1){sup 3+} complex decomposes on a TiO{sub 2} surface. Since the excitation and emission spectra of (Ce{contained in}2.2.1){sup 3+} on silica are very similar to those of the complex in aqueous solution and of those of uncomplexed Ce{sup 3+} ions on silica, no conclusions about the differences in the coordination of the Ce{sup 3+} ion in these surroundings can be drawn based on the authors measurements. |
| Databáze: | OpenAIRE |
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