Eu3+在Ba2TiSi2O8中的发光

The barium titano-silicate phosphors doped with Eu³⁺ were synthesized by high temperature solid state reaction. The structures of as-synthesized samples were characterized by powder XRD. The maximum peaks of emission spectra of Ba₂TiSi₂O₈ and Ba₂TiSi₂O₈∶Eu³⁺ were respectively located at 450 and 618 nm, coming from the transitions of charge-transfer bands of Ti⁴⁺-O^2- and forced electric-dipole transition ⁵D₀-⁷F₂ of Eu³⁺. The luminous mechanisms of Ba₂TiSi₂O₈ and Ba₂TiSi₂O₈∶Eu³⁺ were suggested. The effects of concentration of Eu³⁺ on the luminous performance of Ba₂TiSi₂O₈∶Eu³⁺ were also studied and the results showed that the optimum concentration of Eu³⁺ was 0.12 mol per mole of matrix.     

新型冠醚桥联手性双核Salen配合物的合成及谱学性质

Five novel chiral dinuclear Salen complexes M₂L (M = Fe³⁺Cl^-, Mn³⁺Cl^-, Co²⁺, Ni²⁺, Cu²⁺) and Ba²⁺-crown ether complex H₄BaL(ClO₄)₂ were synthesized. The complexes were synthesized by reaction between ligand 3(H₄L) and corresponding metal salts (FeCl₃, Mn(OAc)₂·4H₂O, Co(OAc)₂·4H₂O, Ni(OAc)₂·4H₂O, Cu(OAc)₂·H₂O, Ba(ClO₄)₂·2H₂O). The chiral two discrete Salen ligand 3 was condensed from 3,3′-[Oxybis(2,l-ethanediyloxy)]bis(2-hydroxybenzaldehyde) and (R,R)-1,2-diamino-cyclohexane. The structure of complexes is two discrete Salen unit bridged with crown ether from two sides. We found that ligand 3 had three complex cites. The two N₂O₂ cavities can found complexes with d-metals (compound 4), while the O₁₀ cavity can found complex with alkali metals and alkaline-earth metals (compound 5). The compounds were characterized by elemental analyses, ¹H NMR, Mass-spectra, FT-IR, UV-Vis and CD spectra. The FT-IR, UV-Vis and CD spectra property of complexes were minutely analyzed.     

Eu3+掺杂SiO2-B2O3-NaF玻璃的制备及发光性质

The Eu-doped SiO₂-B₂O₃-NaF glass was prepared by sol-gel process, using tetraethoxy Silicane, boric acid and sodium fluoride as starting materials, 0.10 mol·L^-1 EuCl₃ solution as the dopant. The luminescent properties of Eu³⁺ doped SiO₂-B₂O₃-NaF phosphors were investigated. The phosphors showed prominent luminescence in pink, the strong emission of Eu³⁺ comes from electronic transition of ⁵D₀- ⁷F₁（591 nm）and ⁵D₀- ⁷F₂（615 nm）,which derived from two transition modes of magnetic-dipole and electric-dipole .The peak intensity of 591nm in SiO₂-B₂O₃-NaF matrix is much stronger than it in the other matrixes, it means that SiO₂-B₂O₃-NaF has sensitization on the transition of ⁵D₀- ⁷F₁ (Eu³⁺). If there are broad bonds in the range of 275～380 nm in the excitation spectrum of Eu³⁺ -doped SiO₂-B₂O₃-NaF glass, the emission peak intensity should be intensified. It is because the electron migration CT band of O^2--Eu³⁺. For all Eu³⁺ concentrations used, the investigation found that when the mass of fraction got to 29.19×10^-3, the luminescence intensity reached the summit. And there is a phenomenon of concentration quenching. Investigation with the same concentration of Eu³⁺ at different annealed temperature, we found that the sample annealed at 400 ℃, the luminescence intensity achieved its maximum value, and Eu³⁺ in this matrix had a phenomenon of temperature quenching. The structural characterization of these luminescent materials was carried by used XRD and TEM. The result showed that the phosphor was in amorphous phase.     

Si5P6O25∶Tb3+的结构与荧光性质

Tb³⁺ ions were incorporated in P-Si matrix material through a sol-gel process. Luminescence properties of Tb³⁺ as a function of dopant， firing temperature， composition and structure of matrices were investigated. The gels synthesized by the reaction of P₂O₅ or H₃PO₄ with tetraethoxy silane and TbCl₃ as dopant were fired in air from the temperature 25～1000℃ to form P-Si crystalline phase. The crystal structure was determined by powder X-ray diffraction. Si₅O(PO₄)₆ were the only crystalline phase and belong to hexagonal crystal system. The emission of ⁵D₄-⁷F₅(～545nm) transition of Tb³⁺ in the P-Si system is composed of two peaks. The amount of doping Tb³⁺ varied from 0.664% to 1.644%， and no obvious concentration quenching was observed in this doping concentra-tion range. The intensity of Tb³⁺ emission increased with firing temperature increasing and becomes stable at 800～1000℃.     

不同温度下VUV光激发的Pr3+离子的发光性质

The luminescent properties of Pr³⁺-doped LaB₃O₆, SrAl₁₂O₁₉, SrB₄O₇ and NaYF₄ in the vaccum ultraviol-et (VUV) range at different temperatures were investigated under the excitation of high-energetic synchrotron radiation. For Pr³⁺ ions in LaB₃O₆, SrAl₁₂O₁₉ and SrB₄O₇, only the parity-forbidden ¹S₀→4f² transitions were observ-ed in the emission spectra at relatively low temperature; but the parity-allowed 4f5d→4f² transitions appeared simultaneously when the temperature was high enough. And the intensity of broad 4f5d→4f² emission increased relative to the intensity of ¹S₀→4f² emissions with increasing temperature. Then the thermal equilibrium model of energy levels was employed to the lowest 4f5d state and ¹S₀ state of Pr³⁺ in the three hosts. The calculated curves were in good agreement with the experimental values, indicating the occurrence of the thermal excitation from ¹S₀ state to 4f5d states at high temperatures when the lowest 4f5d state lies higher than ¹S₀ state and the photon energy is high enough.     

Eu3+在La2O2S中的长余辉发光

The new Eu³⁺ doped lanthanum oxysulfide phosphors,which have the orange-red long afterg low emission,were synthesized by solid-state reaction method.The synthesized phosphors were characterized by X-ray diffraction.The excitation and emission spectra,afterglow spectra and afterglow decay curves were examined.XRD confirmed the phosphor as pure phase La₂O₂S.The phosphors showed typical transitions ⁵D_J(J=0,1) → ⁷J_J(J=0,1,2,3,4)of Eu³⁺.The photoluminescence spectra and afterglow spectra presented the regular alteration with various Eu³⁺ concentration, due to cross relaxation between energy levels of Eu³⁺. In addition, we studied the effects of activator concentration and dopants species on the afterglow property. The data showed afterglow result was the best with 2 % Eu³⁺ and doped with Mg²⁺ and Zr⁴⁺. A prominent phosphorescence can be seen in this phosphor after illuminated with UV light.     

五元体系Li+/Cl-，CO32-，SO42-，B4O72--H2O 298 K相关系实验研究

Zabuye saline lake, Tibet, China, is unrivalled in the world for its high concentration of chloride, sulfate, carbonate and borate of lithium, sodium and potassium. Always at the later stage of the evaporation of brines, most sodium and potassium salts are crystallized out, so the main components of brines can be described with the Li⁺, Mg²⁺/Cl^-, SO₄^2-, CO₃^2-, B₄O₇^2--H₂O system. As a part of study on the equilibrium of this complex system, the equilibrium solubilities and phase diagram of the quinary system Li⁺/Cl^-，CO₃^2-，SO₄^2-，B₄O₇^2--H₂O at 298 K were studied by isothermal dissolution equilibrium method. In the 3-dimentional solubility diagram or its projection diagram saturated with solid LiCl, there are four crystallization fields, four univariant curves and one invariant point. At the invariant point, the saturated solid salts are LiCl·H₂O, Li₂B₄O₇·3H₂O, Li₂CO₃and Li₂SO₄·H₂O. No double salt or solid solution is formed.     

三缺位杂多阴离子α-A-PW9O349-的甲基硅衍生物(TBA)3[α-A-PW9O34(CH3SiO)3(CH3Si)]的合成和晶体结构

Reaction of the trivacant heteropolyanions α-A-PW₉O₃₄^9- with CH₃SiCl₃ leads to the formation of the organosilyl derivative (TBA)₃[α-A-PW₉O₃₄(CH₃SiO)₃(CH₃Si)]. The crystal X-ray diffraction analysis shows that the crystal belongs to orthorhombic with space group Pca2₁, M=3177.09 and the unit cell parameters: a=25.761(5)?,b=14.519(3)?,c=24.396(5)?.V=9124(3)?³,Z=4,D_c=2.225g·cm^-3,μ(MoKα)=11.438mm^-1,F(000)=5464,R=0.0561,R_w=0.0866. The anion consists of one α-A-PW₉O₃₄^9- anion linked by three CH₃SiO⁺ groups, which attached to the fourth CH₃Si through three Si-O-Si bridges.     

超分子化合物{[8-hydroxyquinolineH]44+·[SiW12O40]4-·2H2O}的水热合成、晶体结构及热稳定性

A supermolecular compound, {[8-hydroxyquinolineH]₄⁴⁺·[SiW₁₂O₄₀]^4-·2H₂O} was synthesized by hydrothermal reaction with silico-tungstic acid and 8-hydroxyquinoline. The crystal of the compound belongs to monoclinic system, space group P2₁/n, with a=1.282 6(6) nm, b=2.292 7(4) nm, c=2.092 0(6) nm, β=95.495(2)°, Z=4, V=6.124 1(7) nm³, D_c=3.791 g·cm^-3, μ=22.568 mm^-1, F(000)=6 200, R₁=0.029 3, wR₂=0.069 3, GOF=1.079. Su-permolecular compound is composed of one SiW₁₂O₄₀^4- with Keggin structure, four protonated cations of 8-hydroxyquinoline, two hydrones. Thermal analysis results showed that the anionic skeleton construction of heteropoly acid in compound decomposed approximately at 349.0 ℃. CCDC: 622142.     

类钙钛矿新铌酸盐Ba6LaTi3Nb3O21的合成、结构与介电特性

A New Niobate Ba₆LaTi₃Nb₃O₂₁ was synthesized by high temperature solid state reaction in the BaO-La₂O₃-TiO₂-Nb₂O₅ system. The chemical compositions, crystal structure, microstructure, density and melting point of the new compound were characterized by EPMA, XRD, DTA and so on. Ba₆LaTi₃Nb₃O₂₁ crystallizes the rhombohedral system with unit cell parameters a=0.57388(2) nm, c=4.928 3(3) nm, and space group R3m, Z=3. The structure may be described as six (Nb,Ti)O₆ octahedra corner-sharing along c-axis to form perovskite layer connected by Ba atoms. The Ba₆LaTi₃Nb₃O₂₁ ceramics exhibits high dielectric of 74.1, low dielectric loss of 4.7×10^-4 and small temperature coefficient of dielectric constant of -69 ppm·K^-1 at 1 MHz due to its close structure and relative high dielectric polarizabilities of Ba²⁺, La³⁺, Ti⁴⁺ and Nb⁴⁺. Ba₆LaTi₃Nb₃O₂₁ might be a suitable candidate of high ε_r microwave dielectric ceramics.     

双水相萃取法分离铍(Ⅱ)、铁(Ⅲ)与铁(Ⅱ)、铬(Ⅲ)、锰(Ⅱ)、铝(Ⅲ)

研究了在聚乙二醇2000(PEG)-硫酸钠(Na2SO4)-邻苯二酚紫(PV)体系中铍(Ⅱ)、铁(Ⅲ)、铁(Ⅱ)、铝(Ⅲ)、铬(Ⅲ)、锰(Ⅱ)的萃取行为。试验结果表明,铍(Ⅱ)在pH 3.5-7.0及铁(Ⅲ)在pH 4.0-7.0范围内可以被PEG相几乎完全萃取,而铝(Ⅲ)、铬(Ⅲ)在pH 1.0-7.0、锰(Ⅱ)在pH 1.0-4.5、铁(Ⅱ)在pH 1.0-4.5则不被萃取。从而实现了将铍(Ⅱ)(pH 3.5)、铁(Ⅲ)(pH 5.0)与铝(Ⅲ)、铬(Ⅲ)、锰(Ⅱ)、铁(Ⅱ)混合离子的定量分离。同时探讨了PEG相的萃取机理。     

Cu(Ⅱ)-VO(Ⅱ),Cu(Ⅱ)-Cr(Ⅲ)和Cu(Ⅱ)-Fe(Ⅲ)异双核配合物的合成及表征

合成了三种二 ( 3 羧基水杨醛叉 )缩丙撑二胺 (TS)的Cu(Ⅱ ) VO(Ⅱ )、Cu(Ⅱ ) Cr(Ⅲ )、Cu(Ⅱ ) Fe(Ⅲ )异双核配合物 ,并用元素分析、摩尔电导、IR光谱、UV光谱室温磁矩对配合物的组成和结构进行了表征。磁性研究表明 ,在Cu(Ⅱ ) Fe(Ⅲ )离子间的磁相互作用是反铁磁性的 ,而Cu(Ⅱ ) VO(Ⅱ )、Cu(Ⅱ ) Cr(Ⅲ )离子间是铁磁性相互作用。     

新型席夫碱配体及其Mn3+、Fe3+、Ni2+、Cu2+配合物的合成与表征

0引言手性环氧化物是合成许多天然产物、光学活性材料、光学活性药物等的重要中间体[1]。上世纪60年代以来,手性过渡金属配合物作为烯烃不对称环氧化的催化剂越来越受到人们的重视[2]。研究表明,某些席夫碱金属配合物具有仿酶催化活性,在仿酶催化剂的合成及应用方面占有重要地位[3]。目前,人们将水杨醛衍生物与光学活性胺的席夫碱金属配合物用于不对称环氧化、不对称环丙烷化等反应,具有很高的对映体选择性[4]。同时发现配体的电子效应直接影响配合物的催化活性和对映体选择性。为进一步研究配体的电子性能对配合物催化性能的影响,我们设计…     

Ru(Ⅲ)、Rh(Ⅲ)、Pd(Ⅱ)离子与ct-DNA的相互作用研究

本文以中药小檗碱作为分子探针，在0.01mol·L^-1醋酸-醋酸钠缓冲体系中，用紫外-可见吸收及荧光光谱法研究了Ru(Ⅲ)、Rh(Ⅲ)、Pd(Ⅱ)三种贵金属离子与DNA的键合相互作用。实验发现Ru(Ⅲ)离子对小檗碱-DNA二元体系的荧光有较强的猝灭作用;而Rh(Ⅲ)、Pd(Ⅱ)两种离子则对该二元体系产生显著的荧光敏化作用。考察了EDTA对贵金属离子、小檗碱及DNA三元混合体系的荧光光谱的影响，初步探讨了贵金属离子与DNA可能的键合机理。     

溶剂萃取原子吸收光谱法测定头蜡中铅铬镉镍钴

用高压溶样弹将头蜡用HNO3-H2O2溶解，经0．0500mol/L 8-羟基喹啉体氯仿溶液萃取，用原子吸收光谱法测定痕量铅、铬、镉、镍和钴。方法回收率分别为99．0％、99．5％、96．0％、102％和98．5％，RSD分别为2．9％、3．0％、4．1％、3．8％和2．0％。方法可应用于出口头蜡检测。     

从混合离子中分离Fe,Al,Cd

从混合离子中分离Ｆｅ、Ａｌ、Ｃｄ邓凡政＊石影李霞陈岩（淮北煤炭师范学院化学系淮北２３５０００）关键词聚乙二醇，萃取剂，分离，金属离子１９９６－０４－２３收稿，１９９６－０７－０１修回利用水溶性高聚物聚乙二醇在无机盐存在下可以分成两相的性质［１］，选择...     

呋喃甲酰基吡唑啉酮缩邻氯苯胺席夫碱Cu(Ⅱ),Fe(Ⅲ)和Cr(Ⅲ)配合物的合成与表征

合成1-苯基-3-甲基-4(α-呋喃甲酰基)吡唑啉酮-5缩邻氯苯胺新型席夫碱试剂及其铜、铁和铬配合物,元素分析、摩尔电导数据表明配合物的组成分别为:Cu(L)2,Fe(L)3和[Cr(L)2(H2O)2]Cl.通过红外光谱、紫外光谱、差热-热重分析对配合物进行表征.确证了该配合物的结构.     

酰基吡唑啉酮缩氨基硫脲Ni(Ⅱ),Co(Ⅲ)和Cr(Ⅲ)配合物的合成、表征及生物活性

合成了含硫席夫碱1-苯基-3-甲基-4-(α-呋喃甲酰基)吡唑啉酮-5缩氨基硫脲(HL)及其Ni(Ⅱ),Co(Ⅲ)和Cr(Ⅲ)配合物.元素分析及摩尔电导率表明,新配合物的组成为[NiL2]·C2H5OH,[CoL2]Cl·H2O,[CrL2]Cl·1/2H2O.运用红外光谱、紫外光谱、核磁共振谱和磁矩对配合物进行了表征.抗菌实验表明,配合物具有较强的抗菌生物活性.     

Synthesis and relaxivity of Gd(Ⅲ), Fe(Ⅲ) and Mn(Ⅱ)complexes with dihydropyridine derivative of diethylenetriaminepentaacetic acid

A novel ligand of DTPA-dihydropyridine derivative was synthesized by reaction of DTPA-dianhydride with 4-aniline-1,4-dihydropyridine. Its complexes of gadolinium, manganese and iron were prepared. Their spin-lattice relaxivities (T1) were investigated. The results show that the NMR T1 relaxivitives (R1) for complexes of Fe(Ⅲ), Mn(Ⅱ) are less than that of Gd(Ⅲ) complex,which has a high relaxivity (R1) on the surrounding water protons, indicating that the Gd(Ⅲ) complex possesses the precondition to be contrast agents for magnetic resonance imaging.