Luminescence of (Eu contained in 2. 2. 1) sup 3+ and (Ce contained in 2. 2. 1) sup 3+ cryptates adsorbed on oxide surfaces

• Published in: Journal of physical chemistry (1952) 1991-01, Vol.95:2
• Main Authors: Hazenkamp, M.F., Blasse, G., Sabbatini, N.
• Format: Article
• Language: English
• Subjects: 400102 - Chemical & Spectral Procedures; ADSORPTION ISOTHERMS; AQUEOUS SOLUTIONS; CERIUM COMPLEXES; CHALCOGENIDES; COMPLEXES; DATA; DISPERSIONS; EMISSION SPECTRA; EUROPIUM COMPLEXES; EXPERIMENTAL DATA; INFORMATION; INORGANIC, ORGANIC, PHYSICAL AND ANALYTICAL CHEMISTRY; ISOTHERMS; LUMINESCENCE; MIXTURES; NUMERICAL DATA; OXIDES; OXYGEN COMPOUNDS; RARE EARTH COMPLEXES; SILICON COMPOUNDS; SILICON OXIDES; SOLUTIONS; SPECTRA; TITANIUM COMPOUNDS; TITANIUM OXIDES; TRANSITION ELEMENT COMPOUNDS
• ISSN: 0022-3654; 1541-5740
• DOI: 10.1021/j100155a055

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.