Study of association of Eu(III) β-diketonato-1,10-phenanthroline complexes in silica-based hybrid materials

Hybrid organic-inorganic materials based on silica and mixed-ligand complexes of Eu(III) with β-diketones and 1,10-phenanthroline with covalent and non-covalent attachment to matrix were obtained by a sol-gel route. Luminescent study of obtained systems allowed to propose spectral criteria for estimation of the uniformity of complex distribution in amorphous silica matrix. Thus, such criteria are the broadening of Eu(III) 4f-luminescence bands, emission decay and the shape of plot of the emission intensity vs. concentration of complex in the materials. Full width of 5D0→7F2 band at its half maximum and the ratio of the 5D0→7F2 and 5D0→7F1 bands intensities were used as quantitative measures of spectral changes and the bands broadening in Eu(III) emission spectra.