Preparation, characterization and photophysical properties of highly luminescent terbium complexes incorporated into...

Two new highly luminescent Tb(III) coordination complexes of beta-diketone ligands, [TbL(capital I, Ukrainian)(NO(3))(3)(H(2)O)] 1 [L(capital I, Ukrainian)=N-(2-pyridinyl)ketoacetamide] and [TbL(capital I, Ukrainiancapital I, Ukrainian) (2)(NO(3))(2)(C(3)H(6)O)][TbL(capital I, Ukrainiancapital I, Ukrainian)(NO(3))(4)] 2 [L(capital I, Ukrainiancapital I, Ukrainian)=N-(6-(4-methylpyridinyl))ketoacetamide], were synthesized and characterized by single crystal X-ray diffraction, and incorporated into SiO(2)/polymer hybrid material by sol-gel method resulting in a novel ternary molecular hybrid material. The Tb(III) complexes display characteristic metal-centered luminescence while the ligands emission are completely quenched, showing that efficient ligand-to-metal energy transfer (antenna effect) occurs. The gels can exhibit the characteristic emission bands of terbium ion. In addition, terbium ions present longer fluorescence lifetime in gels than in the corresponding pure complexes powders. Compared with the complexes, the unit mass luminescence intensities of the gels are enhanced. And the increase extent of luminescence intensity of the gel is influenced by the substituent of the ligands. At the same time, concentration effects on the luminescence intensity were investigated. The photo stabilities of the gels under UV radiation are much better than those of the pure terbium complexes.