Spectral and luminescent properties of coumarins in nanoparticles from metal ion complexes
We have studied the absorption spectra of complexes of trivalent ions Y, La, Lu, and Sc with p-phenylbenzoyltrifluoroacetone that were introduced into a solution of 90% H2O + 10% iso-C3H7OH in the absence and presence of either 1,10-phenanthroline or coumarins 6, 7, or 30. We have shown that these coumarins, as well as phenanthroline, are synergistic bidentate ligands that are incorporated into complexes up to concentrations comparable with concentrations of complexes and that stabilize them in the solution. We have studied the dependences of the fluorescence (cofluorescence) intensity (Icofl) of the coumarins on their concentration in nanoparticles from the complexes mentioned above. We have shown that, in nanoparticles from complexes of Y(III), Ln(III), and Sc(III), Icofl of coumarin 30 at high concentrations is higher than Icofl of coumarins 6 and 7. In addition, up to concentrations of coumarin 30 comparable with the concentration of complexes in nanoparticles, there is no concentration quenching of its fluorescence. For coumarins 6 and 7, which are prone to association in the solution under study, the process of incorporating coumarins into complexes competes with their association, which leads to concentration quenching and changes in the shape of their cofluorescence spectra.
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- 1.Dye Lasers, Ed. by F. P. Schäfer (Springer-Verlag, Berlin, 1990).Google Scholar
- 4.G. E. Dobretsov, Fluorescent Probes in Study of Cells, Membranes, and Lipoproteins (Nauka, Moscow, 1989) [in Russian].Google Scholar
- 5.V. N. Beger, Yu. L. Kolesnikov, and A. V. Sechkarev, Opt. Spectrosc. 78(2), 249 (1995).Google Scholar
- 6.Y. Zheng, C. Szymanski, J. McNeil, et al., J. Phys. Chem. B 112, 1772 (2008).Google Scholar
- 19.V. M. Peshkova and N. V. Mel’chakova, β-Diketones (Analytical Reagents) (Nauka, Moscow, 1986) [in Russian].Google Scholar