Synthesis and luminescence properties of rare earth ternary complexes consisting of Tb(Ⅲ), β-diketones and 1,10-phenanthroline (phen)

In order to study the luminescent properties of ternary rare earth complexes with fl-diketone ligand, three new β-diketone ligands, 1-phenyl-3-（p-phenylethynylphenyl）-1,3-propanedione（HPPP）, 1-（2-thienyl）-3-（p-phenylethynylphenyl）-1,3-propanedione （HTPP） and 1-（2-furyl）-3-（p-phenylethynylphenyl）-1,3-propanedione （HFPP）, were synthesized by Sonogashira coupling reaction and Claisen condensation. Three new ternary rare earth complexes, TbL3phen （L = PPP, TPP, or FPP）, were synthesized by the reaction of rare earth chloride TbCl3,1,10-phenanthroline （phen） with HPPP, HTPP, or HFPP respectively, in alcohol solution. The compositions were characterized by means of elemental analysis, chemical analysis, and IR spectra. Luminescent properties of the three new complexes have been studied. The results show that the ternary Yb（Ⅲ） complexes only emit the weak fluorescence of the Tb（Ⅲ） ion, which reveals the triplet state energy of the ligands does not match well with the excited state vibrating energy of Tb^3＋ ion.

Synthesis and luminescence properties of rare earth ternary complexes consisting of Eu(III), β-diketones and 1,10-phenanthroline

Three novel β-diketones （HPPP, HTPP, and HFPP） ligands were synthesized by Sonogashira coupling reaction and Claisen condensation. The structure of β-diketones was confirmed with elemental analysis, IR, NMR and MS spectra. Three new ternary complexes consisting of Eu（Ⅲ）, β-diketones, and 1,10-phenanthroline（phen） were synthesized and characterized as TbL3phen （L=PPP, TPP, FPP） with elemental analysis, chemical analysis, and IR spectra, and their luminescence properties were studied.

The Luminescence Properties and Intramolecular Energy Transfer of Rare Earth Complexes with Aromatic Carboxylic Acids

The triplet state energies of para aminobenzoic acid and nicotinic acid were determined by means of low temperature phosphorescence spectrometry. The energy matches between them and the resonant emitting energy levels of Eu 3+ , Tb 3+ , Sm 3+ , Dy 3+ were studied. The intramolecular energy transfer processes from the two aromatic carboxylic acid ligands to rare earth ions were also discussed on the basis of the measurement results of luminescence intensities, lifetimes and quantum efficiencies.

Synthesis,Characterization,and Luminescence Properties of a Multi-benzoic Acid Rare Earth Complex Applied to Fluorescence Nanometer and Micrometer Fiber

The design and synthesis of a novel multi-benzoic acid ligand and the luminescence properties of the rare earth complex with the ligand and Eu3 +were focused on. The composition and structure of ligand and complex were characterized by Fourier transform infrared( FT-IR) spectroscopy,1H nuclear magnetic resonance(1H NMR) techniques, and element analysis. The luminescent properties,heat resistant performance,morphology and distribution in fibers of the complex were also measured. The fluorescent spectra indicate that as-synthesized complex owns excellent luminescent properties. The maximum relative fluorescence intensity of the complex is more than 7 000. The thermo-gravimetric analysis( TGA) results confirm that the initial degradation temperature of as-synthesized complex is at 413 ℃. Transmission electron microscope( TEM) and field-emission scanning electron microscope( FESEM) photos show that the particle size of assynthesized complex is 50-60 nm,and can be uniformly distributed in fiber. Based on these results, it can be concluded that the synthesized complex has excellent luminescent properties, good thermal stability,and extensively application prospect.

Preparation and Properties of Poly (ethylene terephthalate) Luminescence Fibers with Multi-branched Benzoic Acid Rare Earth Complex

A new multi-branched benzoic acid rare earth complex( MBBAL-Eu( III) complex) was prepared. The advanced tested technologies were employed to characterize the composition and structure of as-prepared complex. Scanning electron microscopy( SEM) image shows that as-prepared complex has a layer structure. Transmission electron microscopy( TEM) image presents that the shape of MBBAL-Eu( III) complex is similar to oval; the size is in the range of 20-50 nm. The thermogravimetric analysis( TGA) curves of MBBAL-Eu( III) complex reveal that as-prepared complex has good thermal stability. The PET luminescence fibers with MBBAL-Eu( III) complex were prepared through meltspinning and electrospun methods. The results prove that asprepared fibers with MBBAL-Eu( III) complex have good luminescent properties and show bright red light.

SPECTRAL VARIATION AND CHARACTERISTICS OF LOW VALENCY RARE EARTH IONS IN COMPLEX OXIDESⅢ.EFFECT OF THE CRYSTAL ENVIRONMENT AND CHEMICAL FACTORS ON LUMINESCENCE PROPERTIES OF EUROPIUM (Ⅱ) ION

In this paper,the influence of crystal-field on the Luminescence properties of Eu^(2+) in complex oxides are studied theoretically by using purely electrostatic model,the dependence of the 4f^65d levels on Eu-O bond distance is given.Quantum chemistry calculation shows that the splitting extent of 4f^65d energy band in cubic or in octahedral fields will be inversely proportional to R^5,where R is the distance of Eu^(2+) to oxygen ligand.The value of R affects slightly the location of the centre of 4f^65d energy band.According to the exper- imental spectrum data,we have discussed the influence of the host chemical composition,the replaced sites of Eu^(2+) and degree of covalency of Eu-O bond on luminescence properties of Eu^(2+).Some regularity of fluorescence spectrum was observed. In alkali-alkaline earth-phosphates,the splitting extent of 4f^65d band (△E) becomes smaller as the Eu-O bond distance (R) increases.In Na_(3-x)(PO_4)_(1-x)(SO_4)_x and Na_(2-x)CaSi_(1-x)P_xO_4 hosts,d-d emission peak of Eu^(2+) will shift to shorter wavelength with the increase of x's value. The crystal structure data show that Eu^(2+) in K_2Mg_2(SO_4)_3 is affected more strongly by crystal-field and covalancy than in KMgF_3,so K_2Mg_2(SO_4)_3:Eu^(2+) emits blue light (E_(em)~m=400nm) and KMgF_3:Eu^(2+) produces ultraviolet fluorescence.

Luminescent Properties of Bi-Rare Earth Complexes with m-methylbenzoic Acid and 1,10-phenanthroline

The bi rare earth complexes EuTb( m MBA) 6(phen) 2·2H 2O, TbY( m MBA) 6(phen) 2·2H 2O were synthesized by the reaction of RECl 3 with m methylbenzoic acid and 1,10 phenanthroline in ethanol solution, where m MBA=m methylbenzoate and phen=1,10 phenanthroline. The luminescence properties of the title complexes were studied in comparison with the corresponding complexes Eu 2( m MBA) 6(phen) 2·2H 2O and Tb 2( m MBA) 6(phen) 2·2H 2O respectively. The results indicate that the emission intensity from europium ion can be greatly enhanced by the terbium ion, while the emission from terbium ion was strongly quenched by europium ion in EuTb( m MBA) 6(phen) 2·2H 2O; the emission intensity from terbium ion can be greatly enhanced by yttrium ion in TbY( m MBA) 6(phen) 2·2H 2O. The mechanism about the results was discussed.

Photoluminescence and electrochemiluminescence studies of chosen rare earths systems

Eu（Ⅲ） complexes with chosen Keggin polyoxomatalates, POM, containing organic counter cations （tetrabutylarnmonium, tetrabutylphosphonium, triphenylethylphosphonium）, were synthesized, and their photophysical properties were studied. The synthesized complexes had the general formula of XnH5-n[EuSiW11O39], formulated based on the results of elemental and thermogravimetric analysis and FTIR spectroscopy. The photophysical properties of the obtained compounds were investigated using photoluminescence and electrochemiluminescence, ECL, methods in solutions and solids. The most intense luminescence of Eu（Ⅲ） was observed for the complexes with tetrabutylarnmonium cations. After the addition of phenanthroline to the XnH5-n[EuSiW11O39] solutions, a large increase in the Eu（Ⅲ） luminescence intensity and a lengthening of its luminescence lifetime were observed as a result of the formation of ternary complexes. Attempts to apply ECL as a method of light emission by generating species capable of forming excited states in Ln/POMs, i.e., Tb（Ⅲ） and Eu（Ⅲ） in the Na9EuW10O36 and Na9TbW10O36 complexes, were made. The influence of the POM complexes on the ECL was also tested using the Tb/EDDHA （EDDA=ethylenediamine di（o-hydroxyphenylacetic acid）） complex, which is effective in generating ECL.

Preparation, Characterization and Luminescent Properties of MCM-41 Type Materials Impregnated with Rare Earth Complex

Hybrid materials incorporating Eu-(TTA)(3). 2H(2)O (7hereafter designated as Eu-TTA, with TTA: thenoyltrifluoroacetone) in unmodified or modified MCM-41 by 3-aminopropyl-triethoxysilane (APTES) were prepared by impregnation method. The obtained materials were characterized using X-ray diffraction (XRD), IR and diffuse reflectance spectroscopy and luminescence spectra. All the hybrid samples exhibited the characteristic emission bands of EU3+ under UV light excitation at room temperature, and the excitation spectra showed significant blue-shifts compared to the pure rare-earth complex. Although the red emission intensity in the modified hybrid was almost the half of the red emission intensity in the pure Eu-TTA complex at room temperature, the hybrid showed a much higher thermal stability due to the shielding character of the MCM-41 host.

An Encapsulation of the Rare Earth Complex in Modified Mesoporous Molecular Sieve MCM-41

The encapsulation of a rare earth (RE) complex Eu(DBM)(3)phen in modified S1-MCM-41 with 3-aminopropyltriethoxysilane is reported for the first time. The luminescence intensity of the RE complex in the modified Si-MCM-41 is about 9 times as strong as in unmodified Si-MCM-41 and the luminescence of the RE complex in the modified SI-MCM-41 has good color purity.

Synthesis, Characterization and Luminescent Properties of Complexes of Rare Earth Nitrates with 2,2′:4′,4″:2″,2- Quaterpyridine

The rare earth nitrate complexes with 2,2′:4′,4″:2″,2 quaterpyridine (L) were prepared in ethylacetate. These new complexes with the general formula [RE(NO 3) 3L]·H 2O (RE = La, Pr, Eu, Tb, Er, Y) were characterized by elemental analysis, IR spectra, thermal analysis and molar conductance measurements. The luminescence properties of these complexes were also studied.

Studies on Intermolecular Energy Transfer and Relaxation Processes in Solid Rare Earth Complexes by Photoacoustic Spectroscopy

The photoacoustic spectra of Eu ( benz)(3) (.) ( phen)(2) ( benz: benzoate, phen: phenanthroline) and Eu-0.(8)Ln(0.2)(benz)(3)(.)(phen)(2)(Ln(3+) : La3+ or Nd3+) were reported. The intermolecular energy transfer processes were studied from the point of the nonradiative transitions. Combined with the fluorescence spectroscopy, photoacoustic spectroscopy reflects the variation of the luminescence efficiencies of solid samples. The luminescence efficiency increases when La3+ is introduced, but it decreases greatly when Nd3+ is added, which is due to the difference of intermolecular energy transfer processes. The models of intramolecular and intermolecular energy transfer and relaxation processes were established.

Synthesis, Structure and Luminescent Properties of Three 1D Chain Rare Earth Complexes

Three 1 D chain coordination polymers [Ln(pydc)2(H2 O)2]n·n Him(Ln = Dy(1), Gd(2), Sm(3), H2 pydc = pyridine-2,5-dicarboxylic acid, Im = imidazole), were solvothermally synthesized by the reaction of pyridine-2,5-dicarboxylic acid(H2 pydc), Ln(Ⅲ) salts and imidazole. They have been characterized by X-ray single-crystal diffraction, IR spectra, TGA analysis and elemental analysis. Structural analyses revealed that complexes 1~3 have similar 1 D chain structures and belong to P1 space group. It is noteworthy that complexes 1~3 exhibited excellent thermal stability and no weightlessness below 117 ℃. Meanwhile, 1 and 3 show characteristic fluorescence of corresponding lanthanide metal ions in solid state at room temperature.

Preparation and Characterization of Layered Compound Zirconium Bis(monohydrogenphosphate) Intercalated with Rare Earth Complex

Layered compound zirconium bis(monohydrogenphosphate)(alpha-ZrP) intercalated with rare earth complex Eu(DBM)(3)phen was prepared. The pre-intercalation of p-methoxyaniline into alpha-ZrP makes the interlayer separation large enough to exchange PMA with europium complex, thus, the luminescent assembly was prepared. This was confirmed by X-ray diffraction, UV-visible spectra and elemental analysis. The fluorescence spectra and lifetime of the assembly were also presented.

Preparation and Properties of Eu^(3+) Rare Earth Complex and Fluorescent Fiber

A novel Eu^3＋ rare earth complex, composed of 4 - hydroxybenzolate acid and 1, 10 - phenanthroline ligands was synthesized. The apparent morphology, composition, thermal stability and fluorescent property of the rare earth complex were measured by TEM, Element analysis, IR, TG and Fluorescence spectrometer. The results indicated that this rare earth complex has sphere-like morphology and its diameter was about 100 nm. The complex has good thermal stability due to the strong coordination between the Eu^3＋ ions and the ligands. Based on the composition analysis, the complex structure formula was： Eu （HOC6 H4 COI）3 （phen） ·H2O Fluorescence spectra showed that the rare earth complex emission peaks were corresponding to the transition of ^5D0→7FJ（J=0,1,2,4）,. and the highest intensity fluorescence peak was at 617 nm. The luminescent fiber was prepared by blending melt-spinning with rare earth complex and polypropylene resin. It also has a good luminescent quality, which the strongest emission peak was at 619 nm. It could be considered suitable for industrial application.

Luminescence intensification of lanthanide complexes by silver nanoparticles incorporated in sol-gel matrix

We present how the luminescence of europium RR-2-P-oxides complexes can be increased by interaction of electronic levels of the complex with the radiation field of silver nanoparticles （NPs）. The procedure by which silver NPs are formed in a sol-gel polyurethane matrix precursor was elaborated. The formed Ag NPs were combined with Eu complex incorporated in ormocer matrix. The emission spectra of the complexes without silver NPs were compared with spectra of the same complexes with addition of silver NPs. As the result of the interaction of the electronic levels of lanthaaide ligands with silver plasmons, dramatic increase of luminescence was observed.

Synthesis of Eu(Ⅲ) and Tb(Ⅲ) Complexes with New Aryl Amide Type Tetrapodal Ligand and Their Luminescence Properties

A new aryl amide type tetrapodal ligand L (1, 1, 1, 1 tetrakis-{[(2 benzylaminoformyl) phenoxyl]methyl}methane) and its europium and terbium nitrate complexes were synthesized. The luminescence properties of these complexes were also studied.

Co-luminescence properties of terbium ions–benzoic acid–phen complexes doped with europium ions

Series of complexes Eux Tb1-x(BA)3phen(0.01 B x B 0.50)were synthesized by co-precipitation method,BA was used as the carboxylic acid ligand and 1,10-phenanthroline was used as the electrically neutral ligand.The samples were characterized by means of X-ray diffraction(XRD),Fourier transform infrared spectroscopy(FT-IR),thermal gravimetric analyses and differential scanning calorimetry(TG–DSC),ultraviolet and visible spectrophotometer absorption spectra,and photoluminescence spectra to study the structure,the energy absorption,the thermal,and luminescent properties of the rare earth complexes.The results show that the series rare earth organic complexes are well crystallized and show high thermal stability.The luminescent intensity of europium ion in the complexes increases as terbium ion transfers the absorbed energy to europium ion in the complexes.The emission of terbium ion at 545 nm is not quenched by europium ion but increases with the content of europium ion decreasing.When the x value is 0.01,the fluorescence intensity reaches the maximum as well as the emission intensity of terbium ions at 545 nm and europium ions at614 nm are almost equal.It realizes the co-luminescence phenomenon of terbium ion and europium ion.The series rare earth organic complexes with different colors can be obtained by adjusting the ratio of terbium ion and europium ion.

Sol Gel Assembly and Luminescence of SiO_2/PEMA Hybrid Material Incorporated with Terbium Complex

Ethyl methacrylate (EMA) doped with luminescent ternary terbium complex (Tb(acac) 3·dam) with acetylacetone (Hacac) and diantipylmethane (dam) was incorporated into the microporous silica gel. With the polymerization of EMA, the hybrid material containing Tb(acac) 3·dam was obtained. The hybrid material exhibited good toughness and transparency and higher thermal stability than that of the pure complex and pure polymer matrix. In the range of doping concentration of Tb(acac) 3·dam (0.05%, 0.1%, 0.2%, 0.5%, 1.0%, 2.0% and 5.0%), emission intensity increases with the increasing of corresponding doping concentration and concentration quenching effect has not taken place.

Thermal Stability and Luminescence Properties of Eu^(3+) and Tb^(3+) Complexes with a Silica Matrix by Sol-Gel Method

Ternary complexes of europium and terbium with benzoic acid and 1, 10 phenanthroline [RE(BA) 3phen] (BA=benzoate phen=1,10 phenanthroline) were introduced into a silica matrix by sol gel method. The thermal stability and luminescence behavior of the complexes in silica gels were studied in comparison with the corresponding solid state complexes by thermal decomposition, excitation and emission spectra. The thermal stability of the complexes is enhanced in silica gel matrix and the luminescence remaines unchanged.