Synthesis of novel europium complexes and their photoluminescence properties

Two novel luminescent Eu(III) complexes with the formulas(NIP)Eu(DBM)3 1 and(ENIP)Eu(DBM)3 2(NIP=2-(naphtha-len-1-yl)-1H-imidazo [4,5-f] [1,10] phenanthroline,ENIP=1-ethyl-2-(naphthalen-1-yl)-1H-imidazo [4,5-f] [1,10] phenanthroline,DBM= dibenzoylmethanato) were successfully synthesized and characterized by IR and elemental analysis.The UV-vis absorption spectra and pho-toluminescence properties of the complexes were investigated,and the irradiation at the absorption band between 300-400 nm of europium complexes either in solution or in the solid state led to the emission of a sharp red band at ~610 nm,a characteristic Eu3+ emission due to the transition of 5D0→7F2.Furthermore,the weak emission bands around 587 and 595 nm attributed to 5D0→7F0 and 5D0→7F1 transition were also displayed in the emission spectra.These results demonstrated that the Eu(III) ion was sensitized efficiently by the ligand and displayed photoluminescence with high intensity,narrow half-peak width,and monochromic light.The excited-state lifetimes of 1 and 2 were in the microsecond time scale,but the photoluminescence quantum yield of 2(0.03) was two times higher than that of 1(0.01) which should be at-tributed to the effect of the ethyl substituting in ENIP.     

Synthesis and spectroscopic properties of rare earth picrate complexes with a new dinaphthalenelamide

The new ligand N-benzyl-2-{2’-[(benzyl-ethyl-carbamoyl)-methoxy]-dinaphthalene-2-yloxy}-N-ethyl-acetamide(L) and its complexes of rare earth picrates were synthesized.The complexes were characterized by elemental analysis,IR,UV-vis spectra and conductivity measurements.The fluorescence properties of the europium complex in solid state and CHCl3,ethyl acetone,acetonitrile and DMF were investigated.Under the excitation,the europium complex exhibited characteristic emissions of europium.The lowest triplet state energy level of the ligand indicated that the triplet state energy level of the ligand matched better to the resonance level of Eu(Ⅲ) than Tb(Ⅲ) ion.     

Triboluminescence of A New Europate Complex

A new europium (Ⅲ)complex Eu(HFNH)3Phen (HFNH: 4, 4, 5, 5, 6, 6, 6-heptafluoro-l-(2-naphthyl)hexane-1,3-dione ; phen : 1, 10-phenanthroline) was synthesized and its tribolumineseent phenomenon was observed. Photoluminescence and tfiboluminescence spectra were successfidly determined. The most intense tfiboluminescent emission originates from the transition of the central Eu^3 ion from ^5D0 level to ^7F2 level. The tribolunlinescent spectrum is basically similar to that of photoluminescence, which correlates with the disorders of F atoms.     

Synthesis and luminescent properties of novel pyrazolone rare earth complexes

A novel pyrazolone pyridine-containing ligand,2,6-bis(1-phenyl-4-ethoxycarbonyl-5-pyrazolone-3-yl)pyridine (H2L) was de-signed and synthesized from pyridine-2,6-dicarboxylic acid (1),and its Eu(III) and Tb(III) complexes were prepared.The ligand and com-plexes were characterized in detail based on FT-IR spectra,1H NMR,elemental analysis and thermal analysis,and the formula of Ln2L3·4H2O (Ln=Eu or Tb) of rare earth complexes was confirmed.The UV-vis absorption spectra and photoluminescence properties of the complexes were investigated,which showed that the Eu(III) and Tb(III) ions could be sensitized efficiently by the ligand (H2L) and emit the photolumi-nescence with high intensity,narrow half-peak width,and monochromic light.The results indicated that the complexes showed potential as excellent luminescent materials.     

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.     

Photophysical properties of a new ternary europium complex with 2-thenoyltrifluoroacetone and 5-nitro-1,10-phenanthroline

A ligand, 5-nitro-1,10-phenanthroline (phenNO2), was synthesized. Its Eu(III) complex with 2-thenoyltrifluoroacetone (HTTA) was prepared and characterized by elemental analysis, IR and 1H NMR spectra. The photophysical properties of the complex were studied in detail by using UV, luminescence spectra, luminescence lifetime and quantum yield. The complex exhibited nearly monochromatic red emission at 612 nm, a remarkable luminescence quantum yield at room temperature (36.0%) upon ligand excitation and a long 5D0 lifetime (458 μs), which indicated that the ligand phenNO2 could sensitize the luminescence of Eu(III) ion efficiently.     

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 con- densation. 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.     

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.     

Synthesis,characterization and fluorescence properties of a novel rare earth complexes with a multi-branched ligand and 1,10-phen

A novel multi-branched ligand with multiple ester groups,multiple benzene rings and multiple carboxyls was synthesized.The composition and structure of the ligand were characterized through the Fourier transform infrared spectroscopy(FT-IR),nuclear magnetic resonance spectrum(1H NMR) and UV spectrometer.The composition and fluorescence properties of rare earth complexes with the ligand and 1,10-phenanthroline(phen) were researched via FT-IR,EA and fluorescent spectrometer.The results presented that the resulting complex had strong characteristic fluorescence spectrum of the rare earth ions,which was attributed to the synergistic effects of the ligand,phen,and rare earth ion.     

Synthesis and spectral characterization of lanthanide complexes with 1,2-diphenyl-4-butyl-3,5-pyrazolidinedione： Luminescent property of Tb（Ⅲ） complex

The complexes of rare earth elements with 1,2-diphenyl-4-butyl-3,5-Pyrazolidinedione (PBH, phenylbutazone) were synthesized and characterized by elemental analysis, molar conductance, IR, UV-Vis, EPR and magnetic moment measurements. Based on these studies the complexes were formulated as [Ln(PB)3(H2O)2]?nH2O, where Ln=Eu(III), Gd(III), Tb(III), Dy(III) and Er(III). From IR spectra, it was found that PBH acted as a bidentate mono-ionic ligand coordinating through two carbonyl oxygen of the pyrazolidinedione ring. The thermal analysis of all the complexes was carried out at a heating rate of 10 oC/min. The kinetic aspects of the complexes were evaluated. The nega-tive entropy value of the complexes indicated a more ordered state for the activated complexes. The photoluminescence property of Tb(III) complex was investigated. It showed all the characteristic emission peaks of Tb3+ with a life time of 0.98914 ms.     

Synthesis, characterization, fluorescence and DNA-binding studies of europium（Ⅲ） pirates complexes with amide-based 2,3-dihydroxynaphthalene derivatives

Two ligands 2,2′-[2,3-naphthylenebis(oxy)]-bis(N-benzyl(acetamide))(L1) and 2,2′-[2,3-naphthylenebis (oxy)]-bis(N,N-diphenyl (acetamide))(L2) and their europium(Ⅲ) picrate complexes were synthesized. The complexes were characterized by elemental analysis, infra-red (IR), thermogravimetry and differential thermal analysis (TG-DTA) and molar conductivity. Fluorescent experiments showed that the resonance level of the Eu) matched better to the triplet state energy level of the ligand L2 than that of the ligand L1 and the fluorescence in-tensities of the complexes were reduced with the raising coordination ability of solvent. In addition, the interactions between the complexes and DNA were studied by means of spectrometry and cyclic voltammetry. The results suggested that the complexes could bind to DNA through intercalation and the complex 1 binded to DNA more strongly than the complex 2.     

Synthesis,characterization and fluorescence properties of a novel rare earth complex for anti-counterfeiting material

A novel ligand with two ester groups,two benzene rings and two carbox yl groups was synthesized. The composition and structure of the ligand were char acterized by the Fourier transform infrared spectroscopy(FT-IR) ,nuclear magnet ic resonance spectrum(NMR) and UV spectrometer. The rare-earth complex with the ligand and 1,10-phenanthroline(phen) was synthesized and structurally charact erized by FT-IR,TG and fluorescent spectrometer. The results showed that the no vel multicarboxyl ligand could efficiently transfer the energy to Eu3+ ions in t he complex and sensitize the luminescence of the rare earth ions,and the comple x could emit strong fluorescence of the rare earth ions.     

Fluorescence and Judd-Ofelt analysis of rare earth complexes with maleic anhydride and acrylic acid

Two kinds of Eu-complexes, Eu(TTA)2(Phen)(AA) and Eu(TTA)2(Phen)(MA) (HTTA=2-Thenoyltrifluoroacetone, Phen=1,10- phenanthroline, AA=acrylic acid, MA=Maleic anhydride), which combined the excellent fluorescence properties of Eu(TTA)2(Phen)(H2O) and the reactivity of acrylic acid and maleic anhydride with radicals, were synthesized. The two complexes were characterized by elemental analysis, infrared (IR) spectra, and X-ray photoelectron spectroscopy (XPS). Based on the data shown from the fluorescent spectra of the Eu-MA and Eu-AA complexes, the ?λ (λ=2 and 4) experimental intensity parameters were calculated. The results demonstrated that the ?2 intensity parameters for the two complexes were smaller than those for the Eu(TTA)2(Phen)(H2O) complex, indicating that a less symmetri- cal chemical environment existed in the complexes. It implied that the radiative efficiency of the 5D0 of these two complexes could be en- hanced by ligand of MA and AA, respectively. The luminescent lifetime of the Eu-AA (τ=7.26×10–4 s) or Eu-MA complex (τ=8.12×10–4 s) was higher than that of the Eu(TTA)2(Phen)(H2O) complex, which was attributed to the substitution of the water molecule (H2O) in Eu(TTA)2(Phen)(H2O) by the MA or AA ligand.     

Synthesis and Photoluminescence Properties of Rare Earth Complexes with 3-Allyl-2, 4-Pentanedione

In order to combine the merits of rare earth organic complexes with excellent material performances of polymers,a polymerizable chelating agent, 3-allyl-2, 4-pentane dione (APD), was synthesized by phase transfer catalysis and its rare earth complexes were prepared. The compounds were characterized by EA, IR and ^1H NMR. Their UV spectra and fluorescence spectra were investigated. The effects of allyl on the luminescence properties of the complexes were studied.The results show that the sensitization of APD is changed by allyl in comparison with that of acetyl acetone (acac), and it becomes an ideal novel ligand of Eu. In addition, intramolecular energy transfer mechanism in the luminescence process in the complexes was also discussed in detail.     

On the Rare Earth Chelates of(1'-Phenyl-3'-Methyl-5'-Pyrazolone-4')-Carbonylmethanoic Acid and 1,10-Phenanthroline

Some rare earth chelates of(1'-phenyl-3'-methyl-5'-phrazolone-4')-carbonylmethanoic acid and 1,10-phenanthroline have been synthesized.The composition of the complexes were confirmed by elemental analy.sis.The molar conductance,IR,~4H-NMR,electronic spectra and thermogravimetric analysis of the chelateshave been measured and discussed.     

Synthesis and Characteristic Study on Complexes of Europium（Ⅲ） and Maleic Acid Doped with Non-Fluorescent Ions

Complex of europium （Ⅲ） with maleic acid, and binuclear complexes of europium（Ⅲ）with maleic acid doped with non-fluorescent ions gadolinium, lanthanum and yttrium, were synthesized. The compositions and structures of complexes were characterized with elemental analysis, single crystal X-ray diffraction, IR and DSC-TG. Fluorescent properties were studied with fluorescence spectrum. The results indicated that the strongest fluorescent complexes were obtained when the ratio of europium and non-fluorescent ion was 8：2. The order of Eu^3＋ fluorescence strengthened by three doped rare earths was Gd^3＋ 〉La^3＋ 〉Y^3＋     

Luminescent properties of Eu（OA）3（TTA）/NBR composites prepared by in-situ reaction

Eu(OA)3(TTA) (OA=cis-9-octadecenoic acid, TTA=4,4,4-trifluoro-1-(2-thienyl)-1,3-butanedione) complexes (Eu- complexes) containing the ligand OA with long molecular chains were synthesized. The Eu(OA)3(TTA) complexes and peroxide were added into nitrile-butadiene rubber (NBR) by mechanical shearing to get the uncured composites. The cured composites were obtained by vulcanizing the uncured composites at high temperature. The in-situ reaction including polymerization and grafting of Eu-complex took place at the curing process, which was verified by Fourier transform infrared spectroscopy (FTIR) and X-ray diffraction (XRD). Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) observations showed the fine dispersion of Eu(OA)3(TTA) complex (Eu-complex) in the cured composites compared with the uncured ones. Fluorescent spectra and Judd-Ofelt parameters analysis revealed that the fluorescent intensity increased approximate linearly with the content of Eu- complex increasing due to the in-situ reaction and long molecular chains of OA. The fluorescent lifetime of composites was longer than that of original Eu-complexes.     

Synthesis and crystal structures of La(Ⅲ),Y(Ⅲ) complexes of homoveratric acid with 1,10-phenanthroline

Two three-dimensional complexes Ln(DMPA)3phen2(HDMPA=3,4-dimet hoxyphenylacetic acid,homoveratric acid;Ln=La,Y;phen=1,10-phenanthroline) were synthesized under hydrothermal conditions and characterized with IR and emission spectra.The crystal structures were determined with single crystal X-ray diffraction method.The two compounds were isostructural,and 3D supramolecule architectures were formed by hydrogen bonds and π-π stacking interactions.They strongly emitted upon excitation due to π→π transition of the ligands.     

Highly luminescent europium and terbium complexes based on succinimide and N-hydroxysuccinimide

The preparation of two highly luminescent europium(III) and terbium(III) complexes with succinimide(SI) and N-hydroxysuccinimide(NHSI) were reported,which were further investigated through elemental chemical analysis,thermal analysis,FT-IR,powder X-ray diffraction,SEM and fluorescence spectroscopy.Data collected through these analysis revealed the formation of the Eu(III) and Tb(III) complexes with the above mentioned ligands at a metal to ligand(M:L) molar ratio of 1:3.Interesting conclusions regarding the efficient sensitization through the coordination site of the lanthanide luminescent centers were retained from the photoluminescent spectra investigation.Strong luminescence emission was observed in case of Eu(III)-SI and Tb(III)-NHSI complexes while the corresponding Eu(III)-NHSI and Tb(III)-SI complexes exhibited no photo luminescent properties.Newly obtained luminescent lanthanide complexes may be of particular interest for various applications in optoelectronics.     

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

Three new rare earth ternary complexes,RE(PPP)3bpy(RE=Sm 3+ ,Eu 3+ ,Tb 3+ ),were synthesized by the reaction of 1-phenyl-3-(p-phenylethynylphenyl)-1,3-propanedione(HPPP)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 Sm 3+ ,Eu 3+ and Tb 3+ complexes exhibited characteristic emission of the central ions.The fluorescence spectra showed that the fluorescence emission intensity of Eu 3+ complex was the strongest.The narrow strongest emission band of Eu 3+ complex was considered to be a valuable material with bright red fluorescence.