Highly Luminescent Poly(Methyl Methacrylate)-Incorporated Europium Complex Supported by a Carbazole-Based Fluorinated β-Diketonate Ligand and a 4,5-Bis(diphenylphosphino)-9,9-dimethylxanthene Oxide Co-Ligand (original) (raw)
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Journal of Photochemistry and Photobiology A: Chemistry, 2014
A series of luminescent materials have been prepared by the ternary europium complex Eu(tta) 3 (phen) (tta = 2-thenoyltrifluoroacetonato, phen = 1,10-phenanotroline) embedded into different polymer matrixes (polystyrene, poly(vinyl difluoride), poly(acrylonitryle) and poly(methyl methacrylate)) in order to investigate the effect of the polymer on the luminescent properties of the hybrid materials. Fourier transform infrared spectra (FTIR), UV/vis spectra, scanning electron microstructure (SEM) and luminescent properties of the europium complex and the hybrid materials are described in detail. In all cases, interaction between the polymer and the europium complex was observed from the above techniques. This interaction was strong enough to lead to a variation in the photoluminescent properties of the hybrid films: while poly(vinyl difluoride) doped polymers showed a reduce quantum yield (= 24%), a dramatic/significant enhanced in this parameter (up to 73%) was observed for the other materials in comparison with the value of the precursor complex (30.5%). This result may support the conclusion that while some polymers could interact with the complex, act as antennae and transfer energy to the central Eu(III) ion, other quench the luminescence of the complex. Based on this high , these films could be applied in top optical applications such as light-emitting diodes and/or active polymer optical fibers.
Dalton Transactions, 2009
A novel b-diketone ligand, 4,4,5,5,5-pentafluoro-1-(9H-fluoren-2-yl)-1,3-pentanedione (Hpffpd), which contains a polyfluorinated alkyl group, as well as a long conjugated fluorene unit, and a chelate phosphine oxide ligand, 4,5-bis(diphenylphosphino)-9,9-dimethylxanthene oxide (DDXPO) were synthesized and utilized for the synthesis of two new europium complexes [Eu(pffpd) 3 (C 2 H 5 OH)(H 2 O)] 1 and [Eu(pffpd) 3 (DDXPO)] 2. For comparison, the [Eu(pffpd) 3 (DPEPO)] 3 complex was also synthesized involving a known chelate phosphine oxide, bis(2-(diphenylphosphino)phenyl) ether oxide (DPEPO). The synthesized complexes have been characterized by various spectroscopic techniques and their solid-state photophysical properties were investigated. The single-crystal X-ray diffraction analyses of 2 and 3 revealed that these complexes are mononuclear, and that the central Eu 3+ ion is surrounded by eight oxygen atoms, six of which are from the three bidentate fluorinated b-diketonates, and the other two oxygen atoms from the chelate phosphine oxide. The coordination polyhedra can be described as distorted square antiprism. Compound 2 has a solid-state photoluminescence quantum yield of 48%, which is about two times higher than that of compound 3 (28%). This may be due to the fact that DDXPO in 1 has the mezzo first triplet excited state energy level (T 1) between the first singlet excited energy level (S 1) and T 1 of Hpffpd, which may support one more additional energy transfer from the T 1 energy level of DDXPO to that of Hpffpd, and consequently improves the energy transfer in the Eu 3+ complex. Furthermore, DDXPO (average Eu-O = 2.34 Å) in complex 2 coordinates more strongly with the central Eu 3+ as compared to DPEPO in complex 3 (average Eu-O = 2.38 Å) which can improve the energy transfer between the ligands and central metal ion, and consequently enhances the photoluminescence efficiency of the corresponding Eu 3+ complex.
Journal of Applied Polymer Science, 2002
Photoluminescent properties of the europium tris(thenoyltrifluoroacetonate) dihydrate [Eu(TTA) 3 (H 2 O) 2 ] incorporated in epoxy resin in the solid state are reported. The polymeric Eu 3ϩ complex and the precursor compound were characterized by elemental analysis, thermogravimetry (TG), differential scanning calorimetry (DSC), infrared spectroscopy, nuclear magnetic resonance (NMR), and electronic spectroscopy. Due to efficient energy transfer from the polymer to the rare earth ion, the polymer phosphorescence intensity was observed to decrease with an increase of the Eu 3ϩ ion concentration. High values of the ⍀ 2 intensity parameter were obtained, reflecting the hypersensitive character of the 5 D 0 3 7 F 2 transition and indicating that the Eu 3ϩ ions are in a highly polarizable chemical environment. This is consistent with systems containing epoxy resin that generally show a higher value for the ⍀ 4 parameter as a consequence of the difference in the basicity of the oxygen donor from the polymer. Lifetime measurement (ϭ 0.442 ms) suggests that the Eu 3ϩ luminescence has a higher efficiency than in the case of hydrated compound (ϭ 0.260 ms). The emission quantum efficiency shows higher luminescence for the polymer containing 1% of Eu 3ϩ--diketonate complex.
Rare Metals, 2019
Five novel europium(III) complexes with 2-[4-(dibutylamino)-2-hydroxybenzoyl]benzoic acid (DAHB) as primary ligand and bathophenanthroline (batho), 2,2'bipyridyl (bipy), 5,6-dimethyl-1,10-phenanthroline (dmph), 1,10-phenanthroline (phen) as ancillary ligands were synthesized via solution precipitation method. The structural formulae of synthesized complexes were speculated to be Eu(DABH) 3 Á2H 2 O (C1), Eu(DABH) 3 Ábatho (C2), Eu(DABH) 3 Ábipy (C3), Eu(DABH) 3 Ádmph (C4) and Eu(DABH) 3 Áphen (C5) by elemental analysis, infrared spectroscopy and proton nuclear magnetic resonance spectroscopy (1 H-NMR). The photoluminescent properties and thermal stability of the complexes were investigated by photoluminescent spectroscopy and thermogravimetric analysis (TG-DTG), respectively. The Commission Internationale de I' Eclairage (CIE) color coordinates, Judd-Ofelt intensity parameter (X 2), total quantum yield, intrinsic quantum efficiency and energy transfer dynamics of complexes were also explored. The excitation spectra of complexes are extended up to visible region. These complexes exhibit characteristic photoemission of Eu 3? metal ion with high color purity in red region attributed to efficient energy transfer from ligand to metal ion. The replacement of water molecules from coordination sphere of europium ion by ancillary ligands results in enhancement of luminescent properties of the C2-C5 complexes, indicating that ancillary ligands act as additional light harvesting centers in sensitization phenomenon. The thermal studies show that these complexes are suitable for meeting the requirement of temperature for fabrication of OLEDs devices.
Central European Journal of Chemistry, 2008
The paper reports on the dependence of the absorbance and luminescent intensity from pH of novel poly(oxyethylene phosphate) tris(β-diketonate) europium (III) complexes. The photophysical data obtained allow some preliminary assumptions about the nature of this phenomenon. Increase in luminescent efficiency is a consequence of enhanced efficiency of energy transfer caused by structural changes in complexes after water deprotonation. Remarkable change has been observed in photophysical properties of the polymer complexes by studying the fluorescent emission and excitation spectra and absorption recorded at various pH both in solution and in the solid state. Some of the complexes derivative of the dibenzoylmethane (DBM) show more than hundred times increase in the luminescence after alkalization. The pH value, at which the maximum luminescent efficiency appears, depends on the type of the fourth ligand. The difference between luminescent efficiency of the complexes in alkaline and neu...
Journal of Materials Chemistry, 2008
In this work is reported the sensitization effect by polymer matrices on the photoluminescence properties of diaquatris(thenoyltrifluoroacetonate)europium(III), [Eu(tta) 3 (H 2 O) 2 ], doped into polyb-hydroxybutyrate (PHB) with doping percentage at 1, 3, 5, 7 and 10% (mass) in film form. TGA results indicated that the Eu 3+ complex precursor was immobilized in the polymer matrix by the interaction between the Eu 3+ complex and the oxygen atoms of the PHB polymer when the rare earth complex was incorporated in the polymeric host. The thermal behaviour of these luminescent systems is similar to that of the undoped polymer, however, the T onset temperature of decomposition decreases with increase of the complex doping concentration. The emission spectra of the Eu 3+ complex doped PHB films recorded at 298 K exhibited the five characteristic bands arising from the 5 D 0 / 7 F J intraconfigurational transitions (J ¼ 0-4). The fact that the quantum efficiencies h of the doped film increased significantly revealed that the polymer matrix acts as an efficient co-sensitizer for Eu 3+ luminescent centres and therefore enhances the quantum efficiency of the emitter 5 D 0 level. The luminescence intensity decreases, however, with increasing precursor concentration in the doped polymer to greater than 5% where a saturation effect is observed at this specific doping percentage, indicating that changes in the polymeric matrix improve the absorption property of the film, consequently quenching the luminescent effect.
Optical Materials, 2004
This work reports on the photoluminescence enhancement of Eu 3+ -doped poly(acrylic acid) using 1,10-phenanthroline as antenna ligand. The polymeric material was synthesized by polymerization in aqueous solution of the monomer partially neutralized with Eu 2 O 3 , containing 1,10-phenanthroline, and using potassium persulfate as initiator. The monomer modification and the coordination of antenna ligand to the Eu 3+ ions were confirmed by 1 H-NMR. The doped polymer was characterized by luminescence spectroscopy. The excitation spectra show clear evidence of the coordination between the Eu 3+ ions and the 1,10-phenanthroline ligands in the polymer matrix. On the other hand, the emission spectra show an inhomogeneous broadening and, together with the relative intensity of the 5 D 0 ! 7 F 1,2 transitions of Eu 3+ , indicate that the dopant ions are uniformly distributed in low symmetry coordination sites. Besides, an enhancement in the intensity of the Eu 3+ characteristic red emission by 1,10-phenanthroline addition is observed, and it is due to the antenna effect of the ligand, which acts as a sensitizer of the Eu 3+ ions. An estimation of the increasing luminescence efficiency is presented.
Molecules
This paper reports the synthesis, structure, photophysical, and optoelectronic properties of five eight-coordinate Europium(III) ternary complexes, namely, [Eu(hth)3(L)2], bearing 4,4,5,5,6,6,6-heptafluoro-1-(2-thienyl)-1,3-hexanedione (hth) as a sensitizer and L = H2O (1), dpso (diphenyl sulphoxide, 2), dpsoCH3 (4,4′-dimethyl diphenyl sulfoxide, 3), dpsoCl (bis(4-chlorophenyl)sulphoxide, 4), and tppo (triphenylphosphine oxide, 5) as co-ligands. The NMR and the crystal structure analysis confirmed the eight-coordinate structures of the complexes in solution and in a solid state. Upon UV-excitation on the absorption band of the β-diketonate ligand hth, all complexes showed the characteristic bright red luminescence of the Europium ion. The tppo derivative (5) displayed the highest quantum yield (up to 66%). As a result, an organic light-emitting device, OLED, was fabricated with a multi-layered structure—ITO/MoO3/mCP/SF3PO:[complex 5] (10%)/TPBi:[complex 5] (10%)/TmPyPB/LiF/Al—using ...
Journal of Materials Science: Materials in Electronics
In this work, [Eu(tta) 3 (4-picNO) 2 ] and [Eu(dbm) 3 (4-picNO)] complexes were incorporated on different concentrations (x = 1, 3, 5, 10 and 15%) in PMMA polymeric matrix (4-picNO: 4-Methylpyridine N-oxide) by the solvent casting method, yielding transparent and highly luminescent polymeric films. These materials were analyzed by X-ray diffraction, scanning electron microscopy and by energy dispersive, ultraviolet-visible spectroscopy, luminescence and vacuum ultraviolet-ultraviolet spectroscopies. The luminescence spectra of doped PMMA films are in agreement with an efficient intramolecular diketonate (tta) ligand-to-europium energy transfer. Furthermore, the values of experimental intensity parameters (Ω 2,4) for luminescent polymeric materials were quite similar to those ones for isolated complexes, indicating that there is a homogeneous dispersion of Eu 3+ complexes in the polymeric matrix, preserving their chemical and structural features. These behavior were also observed from the CIE diagram that show great similarity between the (x,y) coordinates for the doped PMMA samples compared to the isolated β-diketonate complexes with a reddish color tuning. The photostability investigation of the doped PMMA polymeric films and Eu 3+ complexes has been also reported.