Studies on the characterization of novel Eu(III) complexes with beta-diketones and diaza-18-crown-6 / Synth. React. Inorganic Met.-Org. Chem.

Three kinds of novel luminescent complexes of Eu(III) with mixed ligands of beta-diketone and diaza-18-crown-6 ([2,2]) were synthesized: H-2[Eu(TTA)(4)](2).[2,2] (A), [Eu(TTA)(3)](2).[2,2] (B) and [Eu(DBM)(3)](2).[2,2] (C) (HTTA = thenoyltrifluoroacetone, HDBM = dibenzoylmethane and [2,2] = diaza-18-crown-6). Their observed fluorescence intensities are greater than those of the complexes Eu(TTA)(3). 2H(2)O (D) and Eu(DBM)(3). 2H(2)O (E), respectively, with the relative intensity ratios being A : B : D = 13.7 : 3.7 : 1 and C : E = 11.6 : 1. The monochromaticity of fluorescence of these complexes was also found to be improved in A, B and C, presumably because the macrocycle was introduced into the complexes. A possible mechanism of fluorescence enhancement is proposed. The properties of these complexes were determined by TG and DTA methods as well as FT-IR and FT-Raman spectroscopy. / Three kinds of novel luminescent complexes of Eu(III) with mixed ligands of beta-diketone and diaza-18-crown-6 ([2,2]) were synthesized: H-2[Eu(TTA)(4)](2).[2,2] (A), [Eu(TTA)(3)](2).[2,2] (B) and [Eu(DBM)(3)](2).[2,2] (C) (HTTA = thenoyltrifluoroacetone, HDBM = dibenzoylmethane and [2,2] = diaza-18-crown-6). Their observed fluorescence intensities are greater than those of the complexes Eu(TTA)(3). 2H(2)O (D) and Eu(DBM)(3). 2H(2)O (E), respectively, with the relative intensity ratios being A : B : D = 13.7 : 3.7 : 1 and C : E = 11.6 : 1. The monochromaticity of fluorescence of these complexes was also found to be improved in A, B and C, presumably because the macrocycle was introduced into the complexes. A possible mechanism of fluorescence enhancement is proposed. The properties of these complexes were determined by TG and DTA methods as well as FT-IR and FT-Raman spectroscopy.