Syntheses, characteristics, and fluorescence properties of complexes of europium with benzoic acid and its derivatives

The binary complexes of europium with benzoic acid and its derivatives (phthalic acid, m-phthalic acid,o-aminobenzoic acid, salicylic acid, and sulfosalicylic acid) were synthesized and their compositions were identified by elemental analyses. UV and IR of the complexes have been investigated. The UV spectra indicated that the complexes‘ ultraviolet absorption were mainly the ligands‘ absorption. The IR spectra showed that the IR spectra of complexes are different from those of free ligands. The fluorescence properties of them were investigated by using luminescence spectroscopy, the results showed that only three complexes appear as better luminescence, they were Eu-benzoic acid,Eu-m-phthalic acid and Eu-phthalic acid, while the others exhibited the ligands‘ wideband emission.     

Synthesis and fluorescent properties in complexes of Eu(Ⅲ), Tb(Ⅲ), and Sm(Ⅲ) with β-diketone and 2,2'-bipyridine

Three new rare earth ternary complexes,RE(PB)3bpy (RE-Sm3+,Eu3+,and Tb3+),were synthesized by the reaction of 1-(p-phenylethynyl-phenyl)-1,3-butanedione (HPB) and 2,2'-bipyridine (bpy) with rare earth chloride REC13,respectively,in alcohol solution.The compositions were characterized by means of infrared (IR) spectra,chemical analysis,elemental analysis,and thermodynamic analysis.Luminescent properties of the three complexes were studied.At room temperature,under UV light excitation,the Sm3+,Eu3+,and Tb3+ complexes exhibit characteristic emission of the central ions.The fluorescence spectra show that the fluorescence emission intensity of Eu3+ complex is the strongest.The narrow strongest emission band of Eu3+ complex is considered to be a valuable material with bright red fluorescence.     

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.     

Synthesis and fluorescent properties in complexes of Eu(III), Tb(III), and Sm(III) with β-diketone and 2,2′-bipyridine

Three new rare earth ternary complexes, RE（PB）₃bpy (RE=Sm³⁺ , Eu³⁺ , and Tb³⁺ ), were synthesized by the reaction of 1-（p-phenylethynyl- phenyl）-1,3-butanedione （HPB） and 2,2′-bipyridine （bpy） with rare earth chloride RECl₃ , respectively, in alcohol solution. The compositions were characterized by means of infrared （IR） spectra, chemical analysis, elemental analysis, and thermodynamic analysis. Luminescent properties of the three complexes were studied. At room temperature, under UV light excitation, the Sm³⁺ , Eu³⁺ , and Tb³⁺ complexes exhibit characteristic emission of the central ions. The fluorescence spectra show that the fluorescence emission intensity of Eu³⁺ complex is the strongest. The narrow strongest emission band of Eu³⁺ complex is considered to be a valuable material with bright red fluorescence.     

Thermal stability and luminescence properties of 1,10-phenanthroline-tris （m-methylbenzoate） europium （or terbium） complexes in SiO2 gel

Silica gel luminophors containing 1, l O-phenanthroline-tris(m-methylbenzoate) europium (or terbium) complexes were prepared by sol-gel method. The thermal decomposition, excitation and emission spectra for the gel phosphors were measured and compared with that of solid complex powders. The thermal stability of the complexes was enhanced in SiO2 host matrix and the luminescence intensity remained unchanged.     

Synthesis and spectroscopic characterization of fluorescent solid rareearth complexes with hydroxamic acids

The complexes RE2(DHYA)3.nH2O in the title bar were synthesized through some reactions of trivalent rareearth ions.In the process of synthesis,dihydroxam,ic acids were taken as ligands while the alcohol was taken as a solvent.The ligands included adipylhydroxamic acid(ADHA),p-phthalichydroxamic acid(PPHA),oxalohydroxamic acid (OXHA),butadihydroxamic acid(BDHA),o-phthalichydroxamic acid(OPHA),benzoylhydroxamic acid(BHA),etc.Measured at 25℃,the molar conductances in various modes are 13.00-21.05 S.cm^2.mol^-1,which shows that rare-earth complexes are nonelectrolytes and the hydroxamino groups of the complexes have taken part in bonding.Infrared spectra,ultraviolet spectra,nuclear magnetic resonance(1HNMR) spectra,and fluorescence spectra were used to investigate the complexes,Experiments have proved that the complexes of Eu^3 and Tb^3 with aromatic hydroxamic acids have good fluorescent characteristics.     

Synthesis and co-luminescence properties of Tb3+-methacrylic acid-1,10-phenanthroline complexes doped with Eu3+

A series of rare earth complexes Tb1-xEux(MAA)3phen (x=0.00,0.01,0,03,0.05,0.07,0.09,0.10,0.30,and 0.50) were synthesized with MAA as the first ligand and phen as the second ligand.The complexes were characterized by means of FT-IR,thermogravimetry-differential scanning calorimetry (TG-DSC),XRD,UV absorption spectra,and photoluminescence spectra (PL).The results show that the luminescence intensity of Eu3+ increases as Tb3+ transfer the absorbed energy to Eu3+ in the complexes.The emission of Tb3+ at 545 nm is observed and increasing with x decreasing.When x=0.01,the luminescence intensity reaches the maximum value,and the emission intensity ofTb3+ at 545 nm and Eu3+ at 614 nm are almost equal.It realizes the co-luminescence ofEu3+ and Tb3+.We can obtain complexes with different colors by adjusting the ratio of Eu3+ to Tb3+.     

Synthesis and emission analysis of novel rare earth complex Eu（TTA）3（2NH2-Phen）

The rare earth ternary complex of Eu 3+ with thenoyltrifluoroacetone,and 4,7-2NH2 phenanthroline was synthesized and well characterized by UV,fluorescent,IR spectrometry and X-ray diffractometry(XRD)as well as elemental analysis.The results show that the complex of Eu(III)emits strong red luminescence when excited by UV light,and Eu(TTA)3(2NH2-Phen)has the higher sensitized luminescent efficiency and longer lifetime than Eu(TTA)3(Phen).In device of ITO/PVK/Eu(TTA)3(2NH2-Phen)/Al,the spectra of Eu(TTA)3(2NH2-Phen)with different ratios for spin-cast film were monitored.The main emitting peak at 614 nm can be attributed to the transition of 5 D0→ 7 F2 of Eu 3+ and this process results in the enhancement of red emission from electroluminescence device.The effect and mechanism of the ligands on the luminescence properties of europium complex were discussed.The results show that the luminescence intensity of the title complexes greatly increases in comparison with that of their corresponding complexes,revealing that the second ligands form very good synergistic effect with the first ligands.The title complexes possess excellent thermal stability properties,and are hopefully developed into fine PL and EL red materials.     

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 β-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 condensa- tion. 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 Tb(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 Tb3 ion.     

Preparation and characterization of bis(dimolybdo-nonatungstogermanate)lanthanates of potassium

The heteropoly complexes K12[Ln(GeW9Mo2O39)2] · nH2O (Ln = La, Ce, Pr, Nd, and Sm) were prepared for the first time and characterized by chemical analysis, infrared (IR) spectrum, ultraviolet (UV) spectrum, X-ray powder diffraction, and thermal analysis. IR, UV spectra, and X-ray powder diffraction studies show that the structure of the heteropoly complexes is a square antiprism consisting of eight oxygen atoms of two GeW9Mo2O398-, heteropolyanions and a lanthanide ion. The thermostability of heteropoly complexes is lower than that of saturated Keggin structure dodecatungstogermanate.     

Fluorescence of complexes of EuⅢwith aromatic carboxylic acid-1,10-phenanthroline

Fluorescence of complexes of EuⅢwith aromatic carboxylic acid-1,10-phenanthroline@舒万艮 @周忠诚 @牛聪伟~~     

Spectroscopy of related series of Eu and Tb carboxylates

A critical review of the recent works of author and his colleagues on spectroscopy of related series of europium and terbium pyridine-carboxylates and pyridine-dicarboxylates is undertaken. Luminescence, luminescence excitation, IR, Raman, and vibronic spectra of these compounds were discussed. Studies of spectra of the complex lanthanide nitrates with sulfoxides were reviewed also. Intraligand charge transfer (CT) bands in the luminescence excitation spectra were demonstrated by comparison of the spectra of europium and terbium salts. f–d transitions in spectra of some terbium salts were revealed also. A series of complex terbium salts with increasing donor–acceptor interaction of the metal cation and ligand’s nitrogen was forecasted. Comparison of the spectra of pyridine-carboxylate and pyridine-dicarboxylate shed light on the coordination function of the carboxylate groups and on the nature of the ligand-to-metal-ion charge transfer (LMCT) in the lanthanide pyridine-dicarboxylates. The influence of the introduction of spacers in the system of conjugated π-orbitals of the ligands on the rate of the energy transfer to the lanthanide cation was demonstrated also.     

Complexation, luminescence and energy transfer of Ln(III) ions with phenylphosphonic acid

Spectral characterisation of the Ln(III) ion complexes with phenylphosphonic acid (PPA) was made and the mode of Ln(III) ions coordination was established. From the absorption spectra the forces of the Nd³⁺ oscillator were obtained, the intensity of emission and luminescence lifetimes of Eu³⁺ and Tb³⁺ were measured. The Stern–Volmer constants K_sv^φ and K_sv^τ determined indicated the presence of associated forms of complexes. The quantum yield of luminescence of Eu³⁺ and Tb³⁺ complexes was found using Ru(bpy)₃²⁺as a standard. The complexes were characterised by quantum yields (Φ=0.4 and 0.008 for Tb and Eu ions). The solid state Eu³⁺ complex was studied by luminescence spectroscopy, IR and thermogravimetry. The complex was found thermally stable and with no water molecules in its structure.     

Synthesis and fluorescent properties of europium–polymer complexes containing 1,10-phenanthroline

In this paper, 5-acrylamido-1,10-phenanthroline (AP) was synthesized, then the luminescence material containing Eu–polymer complexes were obtained by two methods. The polymer structure and properties were characterized by FT-IR, UV, fluorescence spectra, DSC, GPC, ICP and XRD. Compared with the two methods the rare earth ions-containing polymers, we obtained copolymer B by the second one that had high and stable fluorescence intensity with the Eu content 0.31%. Comparing the two results via different methods, we have set down the useful basement for the study of the luminescence material containing Eu–polymer complexes.     

Spectroscopy of europium and terbium pyridine-carboxylates

Luminescence, luminescence excitation, IR, and Raman spectra of europium and terbium isomeric pyridine-carboxylates: isonicotinates, nicotinates and picolinates were studied. The ways of the excitation energy transfer from the ligand to Ln³⁺ were analysed in dependence on the structure and the type of co-ordination of ligand. Intraligand charge transfer bands and Tb³⁺ f–d transition bands were identified in the luminescence excitation spectra of terbium and europium compounds. Co-ordination of nitrogen atom by terbium ion in picolinates (and dipicolinates) causes low-frequency shift of the f–d bands and promotes the excitation of luminescence through d-states of Tb³⁺.     

Rare earth(iii) complexes with indole-derived acetylacetones II. luminescent intensity for europium(iii) and terbium(iii) complexes

The emission parameters for Eu³⁺(Tb³⁺) complexes with 1-indoleacetylacetone (HL¹), 3-indoleacetylacetone (HL³) and 1-acetylaceto-3-indoleacetic acid (H₂A) and the energy levels of excited triplet states for the three ligands were determined. It was found that L¹ strongly sensitizes Tb³⁺ strongly sensitizes Tb³⁺ luminescence in the complex TbL₃. mH₂O, while all the three ligands sensitize Eu³⁺ luminescence weakly. The energies of excited triplet state for the three ligands are 23 474 cm⁻¹ (L¹), 21 798 cm⁻¹ L³ and 23 310 cm⁻¹ (A) respectively. The facts that all the three ligands sensitize Eu³⁺ weakly and the order of emission intensity for the terbium(III) complexes with the three diketones is L¹ > A > L³ were explained by the relative energy gap between triplet energy level of the ligand and ⁶D₄ of Tb³⁺. This means that the triplet energy level of the ligands is the ligands is the chief factor which dominates Ln³⁺ luminescence.