Association of a terpyridine ligand with lanthanide and copper(Ⅱ) nitrates

Reactions between the 1,3-bis(6-methylpyridin-2-yl) pyridine ligand L,C17H15N3 and LnIII(1a,1b,1c,1d) or a mixture of LnIII and CuII nitrates(2a,2b,2c,2d) resulted in a series of respectively novel mono-and heterodinuclea r complexes,where LnIII=Sm(a) ,Eu(b) ,Tb(c) ,Dy(d) . The compounds were char acterized by elemental analysis,ESI-MS and IR spectra,furthermore we obtained crystals of [H2L][Eu(NO3) 5](1b) and [CuL2][Eu(NO3) 5](2b) suitable for XRD char acterization. In the crystal structures the Eu ions are 10-coordinated with quit e a narrow range of Eu-O distances which are between 0.2436 and 0.2556 nm. In 1b the ligand molecule is protonated in both terminal rings,and the N-H groups ar e involved in the N-H…O hydrogen bonds with the same oxygen atom of one of the nitro groups. These hydrogen bonds connect the ions in 1b into the complex which is the principal building block of the structure. In 2b the [CuL2]2+ counterion s are present;the Cu is octahedrally coordinated by all nitrogen iatoms of two L molecules which are therefore almost perpendicular to each other. The electros tatic interactions between the charged species are in both cases the main drivin g force of the crystal packing.     

Influence of bidentate structure of an aryl phosphine oxide ligand on photophysical properties of its Eu~Ⅲ complex

The bidentate phosphine oxide ligand 1,8-bis(diphenylphosphino) naphthalene oxide (NAPO) and its EuⅢ complex 1 Eu(TTA)3(NAPO) (TTA=2-thenoyltrifluoroacetonate) were chosen to study the effect of bidentate phosphine oxide ligand on the photophysical properties of the corresponding complex. The intramolecular energy transfer processes of 1 were studied. The investigation showed that with bidentate structure NAPO could suppress solvent-induced quenching by enforcing the ligand-ligand interaction and the rigidity of the complex. Contrasted with the monodentate triphenylphosphine oxide (TPPO), NAPO had a higher first triplet excited energy level (T1) and a lower first singlet excited energy level (S1), which fitted to the corresponding excited energy levels of anion ligand TTA much more and supported more efficient singlet and triplet energy transfer in its EuIII complex.     

Electrochemical behavior of cerium（IV） in a RTIL and its mixture with ethanol

A systematic study was carried out to explore the electrochemical behavior of Ce in room temperature ionic liquid（CnmimBr, where n=6, 8, 10） and mixture of C6 mimBr and ethanol by cyclic voltammetry. With increase in the number of carbon atoms on the alkyl substituent on methyl imidazolium cation, the electrochemical window of the ionic liquids was found to extend towards more negative potential value, as a result there was a possibility of reduction of Ce to lower oxidation states. The diffusion coefficient and activation energy for the diffusion were calculated in all the ionic liquids and one of their mixtures with ethanol. With increase in n value, the diffusion coefficient of Ce decreased due to increase in viscosity of the medium while the activation energy for the diffusion followed a reverse trend for C6 mimBr, C8 mimBr and C10 mimBr, respectively. The observations indicated that the nature of species of Ce might be different in room temperature ionic liquids（RTILs） from that present in their mixtures with ethanol.     

Self-polymerization of Eu（TTA）3AA in rubber and their fluorescence effect

A simple europium complex,Eu（TTA）3 AA（TTA=4,4,4-trifluoro-1-（2-thienyl）-1,3-butanedione,AA=acrylic acid） was synthesized by a simple solution method.Then,two kinds of rubber matrix,nitrile-butadiene rubber（NBR） and silicone rubber（SiR） were used as the substrate for Eu（TTA）3 AA to prepare fluorescence composites.The neat Eu（TTA）3 AA complex showed the ability of self-polymerization when it was heated at 145 °C.It was found that the fluorescence intensity of the neat Eu（TTA）3 AA decreased over 70% when the polymerization time was over 25 min at 145 °C.The results also revealed that the polymerizated Eu（TTA）3 AA could be dispersed in nano-scale in two matrices and the luminescent intensities decreased 52% in NBR matrix,and 95% in SiR matrix compared with two relative compounds without crosslinking.To optimize the luminescence intensity of the composites,the Eu（TTA）3 AA polymerization kinetic process in matrix was investigated in detail by controlling the temperature,the crosslinking agent,etc.The results showed that the peroxide could accelerate Eu（TTA）3 AA self-polymerization in the rubber matrix,and therefore improved the dispersion,but not be helpful for the luminescence intensity enhancement.In addition,the relatively higher luminescence intensity in Eu（TTA）3 AA/NBR in comparison to that of Eu（TTA）3 AA/SiR might contribute to the interaction between nitrile group（–CN） in NBR and Eu-complexes,suggesting that the luminescence intensity of the composites also depended on the matrix characteristics.     

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.     

Study on Luminescence Properties of a Novel Rare Earth Complex Eu（ TTA）2 （N-HPA） Phen

A novel rare earth complex Eu（TTA）2（N-HPA）Phen （TTA = thenoyltrifluoroacetone, N-HPA = N-phenylanthranilic acid, and phen = 1,10-phenathroline ）, which contains three different ligands, was synthesized. The Eu complex was blended with poly N-vinylcarbazole （PVK） in different weight ratios and spin coated into films. The luminescence properties of films were investigated and energy transfer between PVK and the complex was discussed. Multilayer structural devices consisting of ITO/PVK： Eu （TTA）2 （N-HPA） phen/BCP/Alq3/Al were fabricated with PVK ： Eu （TTA）2（N-HPA） as light-emitting layer. Increasing the concentration of Eu in the PVK thin film would inhibit the emission of PVK to different degrees. Finally, the pure red luminescence of europium（ Ⅲ ） was observed when the doping weight ratio was approximately 1 ： 5, which indicated an effective energy transfer from PVK to rare earth complex.     

Luminescence of EPDM rubber ultrafine fibers containing nanodispersed Eu-complexes

Polyvinylpyrrolidone/ethylene-propylene-diene terpolymer (PVP/EPDM) sheath/core fibers, with the incorporation of Eu(TTA) 3 Phen (TTA=2-thenoyltrifluoroacetone, Phen=1,10-phenanthroline) complex (Eu-complex) in EPDM, were prepared by coaxial electrospinning. The composite fibers were further vulcanized by peroxide. Scanning electron microscopy (SEM) observations showed that the composite fibers had an average diameter of about 200 nm and a smooth surface. The dispersion of Eu-complexes in the fibers was characterized by transmission electron microscopy (TEM), energy-dispersive X-ray spectroscopy (EDS), and X-ray diffraction (XRD). The studies revealed that the Eu-complex was dispersed in the EPDM fibers in the form of molecular clusters and/or nanoparticles with a diameter smaller than 10 nm. Fluorescence spectra and Judd-Ofelt parameters analysis showed that the luminescent quantum efficiency of the composite fibers was greatly improved when the Eu-complex content was 15 wt.%, because the fine dispersion of Eu-complex in EPDM facilitated the increase of radiative transition rate of the composite fibers over that of the neat complex powder.     

基于相图解析多组元粒子的奥斯特瓦尔德熟化

The coarsening of particles dispersed in a solution was found by Ostwald in 1900. Then, the following cubic law between mean radius (r) and annealing time (t) was established by Lifshitz-Slyozov and Wagner in 1961.-r3--r3/0=[8σVCW/9RT]XαB·t It should be noted, however, that the above equation is valid in the coarsening of B particles in A-B solution. Therefore, some modification is necessary in the case of multi-component materials. For instance, the coarsening of (Fe,Cr)aCb in γFe-M-C matrix is described as follows[1,2] ;-r3--r3/0=[8σVCW/9RT][a b/a]urM/(uoM-urM)2·t According to Eq. (2), the coarsening rate of M23C6 in heat-resistant steel (9%Cr-1%W-0.1%C) depends on the diffusion rate of Cr, because uαCr/(uθCr- uαCr)2＜＜uαw/(uθw- uaw)2. However, experimental data inform us that the rate-determining element is not Cr but W as shown in Fig. 1[3].Fig.1 Effect of W on coarsening of heat-resistant steel Fig.2Equilibrium between M23C6 in this case The problem is solved by modifying the formula of M23C6 from (Fe, Cr, W)23C6 to Fe4 (Cr, W)19C6 in this case(Fig. 2). Consequently, the coarsening equation is expressed as follows.-r3--r3/0=[8σVCW/9RT][29/23][uaW/uow-uaW][1-uaCr-uaW/(19/23)-uaCr-uaW]·t     

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 optical properties of Eu~(3+) ion doped nanocrystalline hydroxya patites embedded in PMMA matrix

Transparent,luminescent and functional nanocomposites demonstrate interesting optical and mechanical properties suitable for many optoelectronic applications.Transparent polymethyl methacrylate(PMMA) polymer nanocomposites modified with thenoyl-trifluoroacetonate(TAA) were fabricated by in situ polymerization and used as hosts for homogenous dispersion of 3 mol.% Eu3+:Ca10(PO4) 6(OH) 2(Eu3+:HA) hydroxyapatite ～20 nm large nanocrystals.The emission,excitation and transmission spectra as well as the fluorescence decay rates of bare Eu3+:HA nanocrystallites,Eu3+:HA embedded in the PMMA and and Eu:HA embedded in the PMMA/TTA nanocomposites were studied.The improvement of transparency was demonstrated with the addition of TTA as well as europium doped hy-droxyapatites in comparison to pure PMMA matrix.The Judd-Ofelt analysis of f-f transitions of Eu3+:HA nanocrystallites,the PMMA/Eu3+:HA and the PMMA+TTA/Eu3+:HA was performed to investigate the optical behavior of the polymeric composites.     

Enhancing extraction ability by rational design of phosphoryl functionalized ionic liquids and mechanistic investigation on neodymium (III) extraction

Four ionic liquids(ILs): 3-(diethoxyphosphoryl)propyl triphenylphosphinium hexafluorophosphate [Ph3PC3P(OEt)2][PF6](IL-1), 3-(ethoxyphenylphosphoryl)propyl triphenylphosphinium hexafluorophosphate [Ph3PC3PPh(OEt)][PF6](IL-2), 3-(diphenylphosphoryl)propyl triphenylphosphinium hexafluorophosphate [Ph3PC3P(Ph)2][PF6](IL-3), and 3-(diethoxyphosphoryl)propyl triphenylphosphinium bis(trifluoromethanesulfonyl)imide [Ph3PC3P(OEt)2][NTf2](IL-4) were synthesized and characterized by IR and 31 P, 1H, 13 C NMR spectroscopy. The liquid-liquid extraction of neodymium(III) by these phosphorus functionalized ionic liquids(PFILs) diluted with common room temperature ionic liquid 1-hexyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide [C6mim][NTf2] was studied. The extraction percentage of Nd(III) was measured as a function of various parameters, such as the initial p H of aqueous phase, equilibrium time, temperature, and concentration of PFIL extractant. The influence of the nature of diluents and salting-out reagents on extraction was also investigated. The results indicated that the extraction process was exothermical and the extraction percentage of Nd(III) by IL-1 was the highest among the PFILs investigated. A possible metal complexation mechanism was proposed for the present PFIL/IL extraction system. And the loaded Nd(III) ions by PFIL could be stripped completely from the ionic liquid phase by 1 mol/L nitric acid.     

1-Methyl-3-octylimidazolium Polyoxomolybdate Ionic Liquid with Low Melting Point and High Stability:Preparation and Photocatalytic Activity

The polyoxometalate(POM)-imidazole ionic liquid(IL) [C8mim]2[Mo6O19](C8mim=1-methyl-3-octylimidazolium) with a low melting point of 82.6 ℃ was successfully prepared and characterized by FTIR., XPS, NMR., TG and so on. The polyoxomolybdate-based IL has high stability, and its decomposing temperature reaches 321 ℃,which is higher than that of 1-alkyl-3-methylimidazolium halides IL. Further photocatalytic performances of the 1L were measured via degrading dye rhodamine B(RB) in aqueous solution under the UV light irradiation. The experiments show that the conversion of RB reaches 80.5% after 90 min under UV-light and the degradation efficiency depends on the pH value of the solution, irradiation time and the dosage of the IL and so on.     

烷基咪唑六氟磷酸离子液体结构与性质的关系研究

应用B3LYP/6-31+G(d,p)方法研究了气相状态下PF6-阴离子与[Mmim]+、[Emim]+、[Pmim]+、[Bmim]+、[Vmim]+、[Hmim]+阳离子形成的离子液体[Mmim]PF6、[Emim]PF6、[Pmim]PF6、[Bmim]PF6、[Vmim]PF6、[Hmim]PF6的平衡几何结构,分析阴阳离子及其构成离子液体分子的电荷分布,阴阳离子的结合方式及其相互作用,并将这些信息与离子液体的熔点、密度、黏度等性质进行了关联,得到了较好的关联度.     

烷基咪唑六氟磷酸离子液体结构与性质的关系研究

应用B3LYP/6-31＋G（d,p）方法研究了气相状态下PF6-阴离子与[Mmim]^＋、[Emim]^＋、[Pmim]^＋、[Bmim]^＋、[Vmim]^＋、[Hmim]^＋阳离子形成的离子液体[Mmim]PF6、[Emim]PF6、[Pmim]PF6、[Bmim]PF6、[Vmim]PF6、[Hmim]PF6的平衡几何结构,分析阴阳离子及其构成离子液体分子的电荷分布,阴阳离子的结合方式及其相互作用,并将这些信息与离子液体的熔点、密度、黏度等性质进行了关联,得到了较好的关联度.     

稀土脯氨酸高氯酸盐配合物[RE_2(Pro)_6(H_2O)_4](ClO_4)_6(RE=Pr,Er)的低温热容及热力学性质

合成了两种纯度分别是 99.2 4%和 98.2 0 %的单晶稀土脯氨酸高氯酸盐配合物 [Pr2 (Pro) 6 (H2 O) 4](Cl O4) 6 和 [Er2 (Pro) 6 (H2 O) 4](Cl O4) 6 ,对该配合物进行了热容、热重、差热和标准燃烧热等测定。在 78～ 370 K温度区 ,用高精密全自动绝热量热仪测定了热容值 ,计算机拟合得其热容对温度的多项式方程分别为 :Cp=140 7.0 8 75 1.6 7X 170 .17X2 89.5 9X3- 76 .11X4和 Cp=1317.99 6 33.0 5 X 16 3.82 X2 15 0 .2 3X3- 86 .2 1X4,[Er2(Pro) 6 (H2 O) 4](Cl O4) 6 的 Cp- T曲线有一熔化峰 ,计算熔点为 35 5 .5 5 K,熔化熵为 6 9.5 42 J/(K m ol) ,熔化焓为2 472 5 .81J/m ol。 TG、DTA技术研究了其热分解过程 ,初步分析了配合物的分解机理。燃烧热实验给出了它们的标准燃烧热分别为 1772 0 .41k J/mol和 1810 1.6 5 k J/m ol     

Synthesis and Crystal Structure of a 4f-3d Complex [La(DMF)_6(H_2O)_3][Cr(CN)_6]·2H_2O

Ｒｅｃｅｎｔｌｙ ,ｔｈｅｒｅｈａｓｂｅｅｎｃｏｎｓｉｄｅｒａｂｌｅｉｎ ｔｅｒｅｓｔｉｎｌａｎｔｈａｎｉｄｅ(Ⅲ )ｈｅｘａｃｙａｎｏｆｅｒｒａｔｅｓａｎｄｔｈｅａｎａｌｏｇｏｕｓｃｏｂａｌｔ(Ⅲ )ａｓｗｅｌｌａｓｃｈｒｏｍｉｕｍ(Ⅲ )ｃｏｍｐｌｅｘｅｓｂｅｃａｕｓｅｏｆｔｈｅｉｒｐｏｔｅｎｔｉａｌａｓｃａｔａｌｙｔｉｃ ,ｓｅｍｉｃｏｎｄｕｃｔｉｖｅ ,ａｎｄｍａｇｎｅｔｉｃｍａｔｅ ｒｉａｌｓ[1～ 4] .Ｆｏｒｅｘａｍｐｌｅ ,ｍａｇｎｅｔｉｃｓｔｕｄｉｅｓｏｎａｓｅｒｉｅｓｏｆｔｈｒｅｅ ｄｉｍｅｎｓｉｏ…