A New Ternary Fluorescent Europium Complex with Bis(Diphenyl Phosphine Oxide) Methane and Thenoyltrifluoroacetone

A fluorescent ternary europium complex containing bis (diphenyl phosphine oxide) methane which functioned as both a neutral and anion ligand, and thenoyltrifluoroacetonato anion was synthesized and characterized by elemental analysis, DTA TG analysis, UV Vis, FT IR and MS spectroscopy. The chemical formula is proved to be Eu(TTA)(MPPO)(HMPPO)·(NO 3)·2H 2O. Its luminescence quantum efficiency(in acetonitrile, 26 3%) is approximately the same as that of the commonly used red emission luminescent compound, Eu(TTA) 3(TPPO) 2 (TPPO is triphenyl phosphine oxide). The new complex has comparatively long fluorescence lifetime.

Influence of Synthesis Parameters on Luminescence of Thenoyltrifluoroacetone Europium Powders

In the last years the development of new luminescent materials was grow highly in order to find efficient materials with low cost of processing. In this way the organic luminescent materials have special attention because its special characteristics, like antenna effect, low temperature processing, possibility to make translation to polymeric and flexible compounds. In this work luminescent powders of TTA:Eu3+ by sol-gel method were synthesized in order to define the synthesis parameters of the highest luminescence. The temperatures of heat treatment were 80°C, 100°C, 200°C and the concentration of Europium where 10%, 20%, 30% and 40% mol (TTA-10Eu, TTA-20Eu, TTA-30Eu, and TTA-40Eu). Fourier Transform Infrared Rays analysis (FTIR) and emission luminescence measures, the best conditions of synthesis were obtained at 40% mol of Europium and 80°C of heat treatment, at 272 nm of excitation. All the samples present the corresponded Eu3+ ion transitions the 5D0 → 7FJ (J = 0, 1, and 2). This confirms the great possibilities of these materials for optoelectronic applications.

Fluorescence Enhancem ent by Gadoliniu m ( Ⅲ) for Com plex of Europiu m ( Ⅲ) with T T Aand T S Aand its Analytical Application

A highly sensitive fluorescence system of the europium gadolinium thenoyltrifluoroacetone tri(salicyloylaminoethyl)amine cetylpyridium bromide polyvinyl alcohol was established and the luminescence mechanism was studied. The excitation and emission wavelengths were 362.5 nm and 613.1 nm respectively. Optimum concentrations of gadolinium, thenoyltrifluoroacetone (TTA), and tri(salicyloylaminoethyl) amine (TSA) were found at room temperature. The effects of surfactants cetylpyridium bromide (CPB) and polyvinyl alcohol (PVA) were also described. The fluorescence intensity varies linearly with the concentration of europium (Ⅲ) in the range 5.00×10 -11 ～6.00×10 -8 mol/L and 1.00×10 -7 ～9.21×10 -7 mol/L. The detection limit is down to 9.02×10 -12 mol/L. The standard addition method was used for the determination of europium in high purity yttrium oxide with satisfactory results.

Solvent extraction and stripping of lithium ion from aqueous solution and its application to seawater

For the development of lithium ion recovery process from seawater, a series of experimental researches were performed. Solvent extraction of lithium ion from aqueous solution using kerosene as solvent was proposed. Lithium ion is effectively extracted by thenoyltrifluoroace- tone-trioctylphosphine oxide （TTA-TOPO） in kerosene within 80 min. Extraction efficiency is severely influenced by stoichiometric parameters. Among the stoichiometric parameters, volume ratio of aqueous （A） to extraction （E） solution is the most influential parameter. After extrac- tion, lithium ion could be easily stripped from the extraction solution by acidic solutions. Stripping efficiency decreases with pH of acidic solutions, and the kind of acid does not affect the stripping efficiency. Extraction efficiency main- tains at more than 93 % even when the extraction solution is recycled three times. 65 % of lithium ion can be extracted from seawater by this solvent extraction process when magnesium ion is precipitated by NHaOH prior to solvent extraction process. Other metallic ions in seawater decrease the extraction efficiency of lithium ion.

Crystal structure and fluorescence spectrum of the complex [Eu(Ⅲ)(TTA)_3(phen)]

The title complex Eu(Ⅲ)(TTA)3(phen) (where TTA= thenoyltrifluoroacetone monoanion; phen = 1,10-phenanthroline) has been synthesized in mixed solvents of acetone and ethanol (1:1 volume ratio) and its crystal structure has been determined by X-ray diffraction. The complex crystals are triclinic, space group P1(#2) with cell dimensions of a = 1.3241 (2) nm, 6 = 1.5278(4) nm, c = 0.9755(3) nm, α = 92.49 (2)°, β=102.57(2)°, γ = 91.62(2)°, V=1.9268(8) nm3, Z = 2, μ(Mo Kα) = 18.77 cm-1, Dx = 1.720 g/cm3. The coordination geometry of Eu atom is a distorted square antiprism, and the encapsulated structure that can meet the structural requirement of the typical europium luminescent sensor. The fluorescence spectrum suggests that the complex is a strong photoluminescent material.