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1.
The spectroscopic behavior of ionic Eu3+ or Tb3+ complexes of an aromatic carboxyl‐functionalized organic salt as well as those of the hybrid materials derived from adsorption of the ionic complexes on Laponite clay are reported. X‐ray diffraction (XRD) patterns suggest that the complexes are mainly adsorbed on the outer surfaces of the Laponite disks rather than intercalated within the interlayer spaces. Photophysical data showed that the energy‐transfer efficiency from the ligand to Eu3+ ions in the hybrid material is increased remarkably with respect to the corresponding ionic complex. The hybrid material containing the Eu3+ complex shows bright red emission from the prominent 5D07F2 transition of Eu3+ ions, and that containing the Tb3+ complex exhibits bright green emission due to the dominant 5D47F5 transition of Tb3+ ions.  相似文献   

2.
Novel EuIII complexes with bidentate phosphine oxide ligands containing a bipyridine framework, i.e., [3,3′‐bis(diphenylphosphoryl)‐2,2′‐bipyridine]tris(hexafluoroacetylacetonato)europium(III) ([Eu(hfa)3(BIPYPO)]) and [3,3′‐bis(diphenylphosphoryl)‐6,6′‐dimethyl‐2,2′‐bipyridine]tris(hexafluoroacetylacetonato)europium(III) ([Eu(hfa)3(Me‐BIPYPO)]), were synthesized for lanthanide‐based sensor materials having high emission quantum yields and effective chemosensing properties. The emission quantum yields of [Eu(hfa)3(BIPYPO)] and [Eu(hfa)3(Me‐BIPYPO)] were 71 and 73%, respectively. Metal‐ion sensing properties of the EuIII complexes were also studied by measuring the emission spectra of EuIII complexes in the presence of ZnII or CuII ions. The metal‐ion sensing and the photophysical properties of luminescent EuIII complexes with a bidentate phosphine oxide containing 2,2′‐bipyridine framework are demonstrated for the first time.  相似文献   

3.
Both silica glass materials singly doped with rare earth organic complex and co-doped with Al^3 were prepared by in situ sol-gel method respectively. XRD and SEM measurements were performed to verify the non-crystalline structure of the glass. The excitation spectra, emission spectra and IR spectra were measured to analyze the influence of the glass contents on the structure of the glass and the energy level of the doped Eu(IH) ions. The effect of Al^3 on the photoluminescence properties of rare earth organic complex in silica glass was investigated. The IR spectra indicated that the in situ synthesized europium complex molecule was confined to the micropores of the host and the vibration of the ligands was frozen. When Al2O3 was doped into the silica host gel, the rare earth ions in the silica network were wrapped up and dispersed by Al2O3, so the distribution of Eu(Ⅲ) complex in the host was morehomogeneous, and the luminescence intensity of ^5D0-^7F2 transition emission of the Eu^3 ions was improved. The results showed that an appropriate amount of Al^3 added to the gel glass improved the emission intensity of the complex in the silica glass, and when the content of Al2O3 reached 4 mol%, the maximum emission intensity could be obtained compared with that of other samples containing different Al2O3 contents.  相似文献   

4.
Ternary europium complexes with thenoyltrifluoroacetone (TTA) and phenanthroline (phen) were incorporated into SiO2/polymer matrix by a sol-gel method. The gels exhibit the characteristic emission bands of europium ion. In addition, Eu3+ presents a longer fluorescence lifetime in gel than in the corresponding pure complex powder. Concentration effects on the luminescence intensity were investigated. The reasons that are responsible for above results are also discussed in the context.  相似文献   

5.
Hybrid materials doped with novel europium complexes were synthesized using PMMA‐co‐Sn12Clusters (copolymers from oxohydroxo‐organotin dimethacrylate and methylmethacrylate) as the matrix material. Two types of hybrid materials were obtained: the physically doped product, PMMA‐co‐Sn12Cluster/Eu(TTA)3phen, and the grafted product, PMMA‐co‐Sn12Cluster‐co‐[EuAA(TTA)2phen] (TTA=2‐thenoyltrifluoroacetone, phen=phenanthroline and AA=acrylic acid). The hybrid materials exhibited characteristic luminescence of the Eu3+ ions, and also showed relative especial optical properties compared with samples just using PMMA as the matrix material. The PMMA‐co‐Sn12Cluster matrix exhibited a high physical doping quantity of [Eu(TTA)3phen], which can be attributed to the special structure of this kind of hybrid material. GPC (gel‐permeation chromatography), TGA (thermogravimetric analysis), SEM, 1H NMR, ICP (inductively coupled plasma), 119Sn NMR, FTIR, and diffuse reflectance techniques were employed to characterize the structures and properties of these hybrid materials.  相似文献   

6.
Herein we report the synthesis of propanoic acid functionalized ionic liquids (ILs) with various lengths of alkyl chain on the imidazole ring. The synthesized propanoic acid functionalized ILs were used to dissolve Eu2O3 (or Tb4O7) due to the formation of europium(III) (or terbium(III)) carboxylate, aimed to get soft luminescent materials combining the properties of ILs and attractive luminescent properties of lanthanide ions. The luminescent behavior of Eu3+ and Tb3+ in the ILs were investigated by luminescence spectroscopy. The affect of the alkyl chain on the luminescent behavior (the asymmetry parameter (R), the lifetime of 5D0, and the 5D0 quantum efficiency) of Eu3+ has been discussed.  相似文献   

7.
Europium(III) fluoride mesocrystals were synthesised in an organic matrix. This matrix is a gel formed by Eu3+ ions and a polycarboxylate/sulfonate copolymer, ACUSOL 588G. In the gel phase, the local amount of europium ions is very high since Eu3+ acts as a crosslinker, and crystallisation occurs upon addition of F. Nucleated seed crystals in the gel phase grow by further ion attachment and form mesocrystals by mutual orientation of the EuF3 particles in the gel. We propose a dipole field as reason for this alignment and that the dipolar character of the particles originates from adsorption of the polyelectrolyte on charged crystal faces.  相似文献   

8.
Four new three‐dimensional isostructural lanthanide–cadmium metal–organic frameworks (Ln–Cd MOFs), [LnCd2(imdc)2(Ac)(H2O)2]?H2O (Ln=Pr ( 1 ), Eu ( 2 ), Gd ( 3 ), and Tb ( 4 ); H3imdc=4,5‐imidazoledicarboxylic acid; Ac=acetate), have been synthesized under hydrothermal conditions and characterized by IR, elemental analyses, inductively coupled plasma (ICP) analysis, and X‐ray diffraction. Single‐crystal X‐ray diffraction shows that two LnIII ions are surrounded by four CdII ions to form a heteronuclear building block. The blocks are further linked to form 3D Ln–Cd MOFs by the bridging imdc3? ligand. Furthermore, the left‐ and right‐handed helices array alternatively in the lattice. Eu–Cd and Tb–Cd MOFs can emit characteristic red light with the EuIII ion and green light with the TbIII ion, respectively, while both Gd–Cd and Pr–Cd MOFs generate blue emission when they are excited. Different concentrations of Eu3+ and Tb3+ ions were co‐doped into Gd–Cd/Pr–Cd MOFs, and tunable luminescence from yellow to white was achieved. White‐light emission was obtained successfully by adjusting the excitation wavelength or the co‐doping ratio of the co‐doped Gd–Cd and Pr–Cd MOFs. These results show that the relative emission intensity of white light for Gd–Cd:Eu3+,Tb3+ MOFs is stronger than that of Pr–Cd:Eu3+,Tb3+ MOFs, which implies that the Gd complex is a better matrix than the Pr complex to obtain white‐light emission materials.  相似文献   

9.
Two chelate ligands for europium(III) having minocycline (=(4S,4aS,5aR,12aS)‐4,7‐bis(dimethylamino)‐1,4,4a,5,5a,6,11,12a‐octahydro‐3,10,12,12a‐tetrahydroxy‐1,11‐dioxonaphthacene‐2‐carboxamide; 5 ) as a VIS‐light‐absorbing group were synthesized as possible VIS‐light‐excitable stable Eu3+ complexes for protein labeling. The 9‐amino derivative 7 of minocycline was treated with H6TTHA (=triethylenetetraminehexaacetic acid=3,6,9,12‐tetrakis(carboxymethyl)‐3,6,9,12‐tetraazatetradecanedioic acid) or H5DTPA (=diethylenetriaminepentaacetic acid=N,N‐bis{2‐[bis(carboxymethyl)amino]ethyl}glycine) to link the polycarboxylic acids to minocycline. One of the Eu3+ chelates, [Eu3+(minocycline‐TTHA)] ( 13 ), is moderately luminescent in H2O by excitation at 395 nm, whereas [Eu3+(minocycline‐DTPA)] ( 9 ) was not luminescent by excitation at the same wavelength. The luminescence and the excitation spectra of [Eu3+(minocycline‐TTHA)] ( 13 ) showed that, different from other luminescent EuIII chelate complexes, the emission at 615 nm is caused via direct excitation of the Eu3+ ion, and the chelate ligand is not involved in the excitation of Eu3+. However, the ligand seems to act for the prevention of quenching of the Eu3+ emission by H2O. The fact that the excitation spectrum of [Eu3+(minocycline‐TTHA)] is almost identical with the absorption spectrum of Eu3+ aqua ion supports such an excitation mechanism. The high stability of the complexes of [Eu3+(minocycline‐DTPA)] ( 9 ) and [Eu3+(minocycline‐TTHA)] ( 13 ) was confirmed by UV‐absorption semi‐quantitative titrations of H4(minocycline‐DTPA) ( 8 ) and H5(minocycline‐TTHA) ( 12 ) with Eu3+. The titrations suggested also that an 1 : 1 ligand Eu3+ complex is formed from 12 , whereas an 1 : 2 complex was formed from 8 minocycline‐DTPA. The H5(minocycline‐TTHA) ( 12 ) was successfully conjugated to streptavidin (SA) (Scheme 5), and thus the applicability of the corresponding Eu3+ complex to label a protein was established.  相似文献   

10.
We report here on the preparation of novel luminescent core‐shell material by initial coating with polyelectrolytes and subsequent with a silica shell on the lanthanide complexes loaded zeolite L microcrystals. Lanthanide complexes loaded zeolite L was prepared by insertion of 2‐thenoyltrifluoroacetone (TTA) into the nanochannels of zeolite crystals by gas diffusion of TTA to Eu3+ exchanged zeolite L, coating a silica shell on the lanthanide complexes loaded zeolite L resulted to the novel luminescent core‐shell material. The luminescent core‐shell material was further functionalized with silylated terbium(III) complex and the obtained material was used as the luminescence sensing of dipicolinic acid (DPA), which is a major constituent of many pathogenic spore‐forming bacteria.  相似文献   

11.
A practicable synthesis method is explored to synthesize a europium porphyrin complex in which a water‐soluble positively charged 5,10,15,20‐tetrakis(4‐trimethylammoniophenyl)porphyrin iodide, H2TMePPI, is immobilized into the sol‐gel silica matrix and then in‐situ metallized with the Eu3+ ion. The product is characterized by means of the solid UV diffusion reflection spectra, fluorescence spectra, and thermal gravimetric analysis (TG). The solid UV diffusion reflection spectra show that the number of Q bands in the product is less than that of the H2TMePPI ligand, which is one of the important characteristics of porphyrin metallization. The fluorescence spectra of the product are different from that of the silica doped with free Eu3+ ions, implying the different function of Eu3+ ions in the product. The TG curves show that the thermal stability of the Eu(III)TMePPI entrapped into silica is higher than that of the H2TMePPI. The effect of a heat treatment and an UV‐light irradiation on the photoluminescence properties of the composite is investigated in details. The stronger interaction between Eu(III)TMePPI and SiO2 in the composite is responsible for the different spectra.  相似文献   

12.
Side‐chain vinyl poly(dimethylsiloxane) has been modified with mercaptopropionic acid, methyl 3‐mercaptopropionate, and mercaptosuccinic acid. Coordinative bonding of EuIII to the functionalized polysiloxanes was then carried out and crosslinked silicone elastomers were prepared by thiol–ene curing reactions of these composites. All these europium complexes could be cast to form transparent, uniform, thin elastomers with good flexibility and thermal stability. The networks were characterized by FTIR, NMR, UV/Vis, and luminescence spectroscopy as well as by scanning electron microscopy, thermogravimetric analysis, and X‐ray photoelectron spectroscopy. The europium elastomer luminophores exhibited intense red light at 617 nm under UV excitation at room temperature due to the 5D07F2 transition in EuIII ions. The newly synthesized luminescent materials offer many advantages, including the desired mechanical flexibility. They cannot be dissolved or fused, and so they have potential for use in optical and electronic applications.  相似文献   

13.
The effect of laser irradiation at λexc 266 nm onto the fluorescence characteristics of EuIII in solution of the ionic liquid 1‐methyl‐3‐butyl‐1H‐imidazolium bis[(trifluoromethyl)sulfonyl]amide (C4‐mimTf2N) was examined for various amounts of H2O added. Stable radiolytic products that were generated at very low doses (in the range of 4 kGy) were very reactive with EuIII and led to the appearance of a new europium luminescent species that was characterized by lifetime, relative intensity, and emission spectrum. Although the lifetime and the intensity depended on the H2O content, the emission spectrum was not influenced by H2O. It was shown that large amounts of H2O, although not preventing radiolysis of C4‐mimTf2N, inhibited the complexation with EuIII.  相似文献   

14.
The 1D chain red luminescent europium coordination polymer: {[Eu2L6(DMF)(H2O)] · 2DMF · H2O}n ( I ) (L = 4‐chloro‐cinnamic acid anion, C9H6ClO2, DMF = N, N‐dimethylformamide) was synthesized by the reaction of Eu(OH)3 and 4‐chloro‐cinnamic acid ligand. The structure of the coordination polymer was determined by single‐crystal X‐ray diffraction analysis. It reveals that there exists two crystallographically nonequivalent europium atoms in each unit of this coordination polymer and Eu3+ ions are connected by two alternating bridging modes to form an endless polymer structure. The luminescent properties and energy transfer process in the complex are investigated at room temperature.  相似文献   

15.
Herein, EuIII‐doped 3D mesoscopically ordered arrays of mesoporous and nanocrystalline titania are prepared and studied. The rare‐earth‐doped titania thin films—synthesized via evaporation‐induced self‐assembly (EISA)—are characterized by using environmental ellipsoporosimetry, electronic microscopy (i.e. high‐resolution scanning electron microscopy, HR‐SEM, and transmission electron microscopy, HR‐TEM), X‐ray diffraction, and luminescence spectroscopy. Structural characterizations show that high europium‐ion loadings can be incorporated into the titanium‐dioxide walls without destroying the mesoporous arrangement. The luminescence properties of EuIII are investigated by using steady‐state and time‐resolved spectroscopy via excitation of the EuIII ions through the titania host. Using EuIII luminescence as a probe, the europium‐ion sites can be addressed with at least two different environments within the mesoporous framework, namely, a nanocrystalline environment and a glasslike one. Emission fluctuations (5D07F2) are observed upon continuous UV excitation in the host matrix. These fluctuations are attributed to charge trapping and appear to be strongly dependent on the amount of europium and the level of crystallinity.  相似文献   

16.
In this study, a series of Sr(LiAl3)1?x(SiMg3)xN4:Eu2+ (SLA‐SSM) phosphors were synthesized by a solid‐solution process. The emission peak maxima of SLA‐SSM range from 615 nm to 680 nm, which indicates structural differences in these materials. 7Li solid‐state NMR spectroscopy was utilized to distinguish between the Li(1)N4 and Li(2)N4 tetrahedra in SLA‐SSM. Differences in the coordination environments of the two Sr sites were found which explain the unexpected luminescent properties. Three discernible morphologies were detected by scanning electron microscopy. Temperature‐dependent photoluminescence and decay times were used to understand the diverse environments of europium ions in the two strontium sites Sr1 and Sr2, which also support the NMR analysis. Moreover, X‐ray absorption near‐edge structure studies reveal that the Eu2+ concentration in SLA‐SSM is much higher than that in in SrLiAl3N4:Eu2+ and SrSiMg3N4:Eu2+ phosphors. Finally, an overall mechanism was proposed to explain the how the change in photoluminescence is controlled by the size of the coordinated cation.  相似文献   

17.
A novel orange‐yellow‐emitting Ba3Gd(PO4)3:x Eu2+,y Mn2+ phosphor is prepared by high‐temperature solid‐state reaction. The crystal structure of Ba3Gd(PO4)3:0.005 Eu2+,0.04 Mn2+ is determined by Rietveld refinement analysis on powder X‐ray diffraction data, which shows that the cations are disordered on a single crystallographic site and the oxygen atoms are distributed over two partially occupied sites. The photoluminescence excitation spectra show that the developed phosphor has an efficient broad absorption band ranging from 230 to 420 nm, perfectly matching the characteristic emission of UV‐light emitting diode (LED) chips. The emission spectra show that the obtained phosphors possess tunable color emissions from yellowish‐green through yellow and ultimately to reddish‐orange by simply adjusting the Mn2+ content (y) in Ba3Gd(PO4)3:0.005 Eu2+,y Mn2+ host. The tunable color emissions origin from the change in intensity between the 4f–5d transitions in the Eu2+ ions and the 4T16A1 transitions of the Mn2+ ions through the energy transfer from the Eu2+ to the Mn2+ ions. In addition, the mechanism of the energy transfer between the Eu2+ and Mn2+ ions are also studied in terms of the Inokuti–Hirayama theoretical model. The present results indicate that this novel orange‐yellow‐emitting phosphor can be used as a potential candidate for the application in white LEDs.  相似文献   

18.
This article describes a green synthetic approach to prepare water dispersible perovskite‐type Eu3+‐doped KZnF3 nanoparticles, carried out using environmentally friendly microwave irradiation at low temperature (85 °C) with water as a solvent. Incorporation of Eu3+ ions into the KZnF3 matrix is confirmed by strong red emission upon ultraviolet (UV) excitation of the nanoparticles. The nanoparticles are coated with poly(acrylic acid) (PAA), which enhances the dispersibility of the nanoparticles in hydrophilic solvents. The strong red emission from Eu3+ ions is selectively quenched upon addition of CuII ions, thus making the nanoparticles a potential CuII sensing material. This sensing ability is highly reversible by the addition of ethylenediaminetetraacetic acid (EDTA), with recovery of almost 90 % of the luminescence. If the nanoparticles are strongly attached to a positively charged surface, dipping the surface in a CuII solution leads to the quenching of Eu3+ luminescence, which can be recovered after dipping in an EDTA solution. This process can be repeated for more than five cycles with only a slight decrease in the sensing ability. In addition to sensing, the strong luminescence from Eu3+‐doped KZnF3 nanoparticles could be used as a tool for bioimaging.  相似文献   

19.
The non‐ionic europium(III) complex [Eu(TTA)3·DAF]·0.5C7H8 (TTA = 2‐thenoytrifluoroacetonate, DAF = 4, 5‐diazafluoren‐9‐one) was synthesized. The structural determination has been carried out. DAF coordination induces the both excitation spectra in the solid state and solution having a red shift and sensitizes Eu3+ luminescence under visible light excitation.  相似文献   

20.
A new mononuclear europium complex incorporating the (+)‐di‐p‐toluoyl‐d ‐tartaric acid (d ‐H2DTTA) ligand, namely, catena‐poly[tris{μ2‐3‐carboxy‐2,3‐bis[(4‐methylphenyl)carbonyloxy]propanoato}tris(methanol)europium(III)], [Eu(C20H17O8)3(CH3OH)3]n, (I), has been synthesized and characterized by IR spectroscopy, elemental analysis, powder X‐ray diffraction and single‐crystal X‐ray diffraction analysis. The structure analysis indicates that complex (I) crystallizes in the trigonal space group R3 and exhibits an infinite one‐dimensional chain structure, in which the Eu3+ ion is surrounded by six O atoms from six d ‐HDTTA? ligands and three O atoms from three coordinated methanol molecules, thus forming a tricapped trigonal prism geometry. The d ‐H2DTTA ligand is partially deprotonated and adopts a μ1,6‐coordination mode via two carboxylate groups to link adjacent Eu3+ ions, affording an infinite one‐dimensional propeller‐shaped coordination polymer chain along the c axis, with an Eu…Eu distance of 7.622 (1) Å. Moreover, C—H…π interactions lead to the formation of helical chains running along the c axis and the whole structure displays a snowflake pattern in the ab plane. The circular dichroism spectrum confirms the chirality of complex (I). The solid‐state photoluminescence properties were also investigated at room temperature and (I) exhibits characteristic red emission bands derived from the Eu3+ ion (CIE 0.63, 0.32), with a reasonably long lifetime of 0.394 ms, indicating effective energy transfer from the ligand to the metal centre. In addition, a magnetic investigation reveals single‐ion magnetic behaviour. The spin‐orbit coupling parameter (λ) between the ground and excited states is fitted to be 360 (2) cm?1 through Zeeman perturbation. Therefore, complex (I) may be regarded as a chiral optical‐magneto bifunctional material.  相似文献   

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