EuPO4∶Zn@MCM-41的制备和发光性质

通过微波辅助水热法合成MCM-41介孔材料,经溶胶凝胶组装过程将EuPO₄∶Zn分散到MCM-41表面上和孔道中,制备成以MCM-41为基质的复合发光材料EuPO₄∶Zn@MCM-41粉末。通过XRD、FTIR、氮吸附、SEM、HRTEM、EDS对该材料进行了表征,用单因素法探究了原料配比(Eu(NO₃)₃、Zn(NO₃)₂的加入量和反应条件(煅烧的温度、时间)对EuPO₄∶Zn@MCM-41在593 nm处发光强度的影响,并研究其影响机理。荧光分析发现,EuPO₄∶Zn基本不发射荧光,而EuPO₄∶Zn@MCM-41材料具有蓝光段和红光段的荧光发射,主要发光带以468和593 nm为中心。593 nm处的发射归因于Eu³⁺的4f组内⁵D₀→⁷F₁跃迁,即Eu³⁺中心离子所在晶格格位对称性决定的磁偶极跃迁。研究表明以MCM-41为载体,能够大大降低颗粒的团聚程度,并使EuPO₄:Zn颗粒具有更小的粒径;同时EuPO₄∶Zn@MCM-41中Eu³⁺发光中心具有更大的裂分,MCM-41的纳米孔道使Eu³⁺的发光中心分离,降低了Eu³⁺之间电子云之间的重叠,大大减小了荧光的猝灭,因此MCM-41能有效降低Eu³⁺复合物荧光猝灭。     

氧化石墨烯表面生长铕配合物纳米晶及其荧光性能研究

本文利用π-π堆积的方式在氧化石墨烯(GO)表面生长了Eu(Ⅲ)配合物纳米晶。傅立叶变换红外光谱(FTIR),透射电子显微镜(TEM),X-射线衍射(XRD)的表征证明,Eu(Ⅲ)配合物纳米晶成功地生长在氧化石墨烯表面。荧光光谱分析证明,复合材料具有一定的荧光性能,其中Eu³⁺的猝灭浓度为18wt%。热重分析显示,复合材料的热稳定性也比纯配合物有了明显的提高。     

希土与L-甲状腺素(T4)相互作用的研究

在二甲亚砜-水混合溶剂中用pH电位法测定了T4的质子化常数以及与五种希土离子(Pr³⁺、Eu³⁺、Gd³⁺、Tb³⁺、Yb³⁺)生成配合物的稳定常数。体系中主要生成110型配合物，紫外吸收光谱，HNMR表明，在较低pH值，T4通过羧基与希土配位，pH较高时，氨基也相继配位。配位键以离子性为主，荧光光谱表明，T4对中心希土离子的荧光有猝灭作用。     

荧光法研究偏钒酸钠与牛血清白蛋白的相互作用

本文用荧光光谱和紫外可见吸收光谱研究了在模拟人体生理条件下，偏钒酸钠与牛血清白蛋白(BSA)结合反应的特征，研究了紫外灯(253.7 nm)照射对偏钒酸钠与BSA结合的影响。紫外吸收光谱显示，加入偏钒酸钠后，牛血清白蛋白的紫外吸收降低，表明偏钒酸钠与BSA形成了缔合物。荧光猝灭光谱显示偏钒酸钠对牛血清白蛋白有较强的荧光猝灭作用，荧光猝灭机理符合静态机制。缔合物的稳定常数分别为：K_s=0.357×10⁴(25 ℃)，K_{s相似文献}   

Cu2+与烟草多酚氧化酶相互作用研究

本文通过酶活性测定，荧光光谱和紫外光谱研究了外加Cu²⁺与烟草多酚氧化酶(简称PPO)的相互作用。结果表明，微量铜的加入能增加酶的活性，[Cu²⁺]/[PPO]为0.20左右时酶活性最大，[Cu²⁺]/[PPO]为0.91时，Cu²⁺开始表现出对PPO活性的抑制;Cu²⁺对PPO内源荧光的猝灭机制属于形成络合物所引起的静态猝灭，猝灭常数K_sv为8.0375×10³L·mol^-1;Cu²⁺的加入使PPO蛋白质分子构象发生变化，α-螺旋含量增加，多肽链及Trp和Tyr残基的芳杂环进一步向分子内收缩，疏水基团之间的疏水作用增强。     

多色发光层状稀土氢氧化物/聚甲基丙烯酸甲酯复合荧光薄膜的组装

本文通过水热法合成了含有3种不同稀土离子的层状稀土氢氧化物 (Gd_0.5Tb_0.5-xEu_x)₂(OH)₅NO₃·nH₂O, 并选择有机物水杨酸(HSA)作为敏化剂, 通过在水热条件下的离子交换反应, 成功将其以有机阴离子形式与层状稀土氢氧化物插层组装获得有机-无机杂化荧光材料(SA^--LRHs:xEu)。荧光性质测定表明, SA^-通过有效的能量转移增强了Tb³⁺的特征绿色荧光发射, 随着Eu³⁺含量的增加, Eu³⁺的特征红色荧光发射随之增强, 而Tb³⁺的特征绿色荧光发射随之减弱。在此基础上, 将发光颜色可调的有机-无机荧光材料与聚甲基丙烯酸甲酯(PMMA)复合组装出透明的荧光薄膜。     

淋巴细胞膜上Na+/Ca2+交换操纵的Eu3+内流的荧光法研究

利用Fura-2荧光浓度指示剂法、通过检测360nm激发荧光强度的变化,研究了Eu³⁺能否利用人外周血淋巴细胞膜上的Na⁺/Ca²⁺交换进入细胞。结果表明:用ouabain预处理细胞无Na⁺介质中测试,当加入Eu³⁺时,360nm荧光强度发生猝灭,且随着胞外加入的Eu³⁺浓度的增大而猝灭增强。表明在实验条件下Eu³⁺可以进入细胞。电压依赖性Ca     

色氨酸-镝(Ⅲ)配合物与鲱鱼精DNA的作用方式

采用UV光谱法、荧光光谱法,在pH=7.40的缓冲溶液中确定了镝(Ⅲ)与色氨酸的结合比n_Dy(Ⅲ)∶n_Trp=1∶3,Dy(Ⅲ)(Trp)₃配合物与鲱鱼精DNA的结合比n_{Dy(Ⅲ)(Trp)3}∶n_DNA=2∶1。用双倒数法确定了结合常数K_25℃=5.75×10⁴ L·mol^-1和K_37℃=3.27×10⁴ L·mol^-1。化学热力学研究显示配合物Dy(Ⅲ)(Trp)₃与hsDNA的结合为熵和焓共同驱动。结合Scatchard法和粘度法,确定了配合物Dy(Ⅲ)(Trp)₃与hsDNA之间主要为静电作用和嵌插作用。     

荧光法研究3-氨基苯硼酸与牛血清白蛋白间的相互作用

为了了解分子印迹反应的机理和最适宜的反应条件, 应用荧光猝灭法研究了3-氨基苯硼酸(APBA)与牛血清白蛋白(BSA)的相互作用, 二者的反应受到体系pH值、离子强度等关键因素的影响. 实验结果表明: 适宜的离子强度和pH值为6.25时, APBA与BSA的色氨酸残基的荧光猝灭反应的物质的量比为2∶1, 表观结合常数K_A＝1.0×10¹¹ L²• mol^－2, 说明二者间形成了较强的化学键. 通过上述研究, 明晰了3-氨基苯硼酸与牛血清白蛋白之间的作用机理, 有助于分离或富集蛋白质中BSA组分, 从而能够改进印迹和洗脱的效率.     

CaWO4中Eu3+的长余辉发光

Eu³⁺ activated CaWO₄ was prepared by high temperature solid state reaction technique. Red afterglow was observed for in the CaWO₄∶Eu after exciting with 254 nm light due to Eu³⁺ transition from ⁵D₀ to ⁷F_J (J=0, 1, 2, 3,4). By the calculation of the thermoluminescence spectrum of CaWO₄∶Eu, we conclude that there were two types of trap centers: V_Ca″ was formed by substitution of Ca²⁺ by Eu³⁺ and complex traps were produced because of substitution of W⁶⁺ by Eu³⁺.     

铜(Ⅱ)离子与神经红蛋白的相互作用

利用紫外可见吸收光谱、荧光光谱、同步荧光光谱及圆二色(CD)光谱研究了铜髤离子与神经红蛋白(NGB)的相互作用。结果表明,Cu2+离子使NGB在280nm处的紫外吸收增强,说明Cu2+与NGB发生了相互作用;Cu2+使NGB内源性荧光发生猝灭,其猝灭机制为静态猝灭;同步荧光光谱表明,Cu2+使色氨酸微环境的疏水性有所降低,Cu2+对NGB的作用位点更接近于色氨酸;CD光谱显示Cu2+没有引起NGB二级结构明显的变化。     

碳笼氧化物的结构和谱学性质

碳笼氧化物对碳笼的官能团化研究具有重要意义，因而激起了人们广泛的研究兴趣。本文对碳笼氧化物C₆₀O_n、C₇₀O_n、C₇₆O_n、C₇₈O_n及C₈₀O_n的结构、电子光谱、红外光谱及核磁共振谱的研究进展进行综合评述。介绍了国内外近十几年来众多研究小组的工作，并结合作者本人在此方面的理论研究成果，进一步探索碳笼氧化物的结构特点以及光谱性质的规律性。在对C₆₀及C₇₀氧化物研究结果与实验符合的基础上，预测高碳笼氧化物的结构和光谱。     

Synthesis and structural studies of complexes of Co(II), Ni(II), Cu(II), Zn(II) and Cd(II) with substituted chalcones

Complexes of Co(II), Ni(II), Cu(II), Zn(II) and Cd(II) with 3-(2-pyridyl)-1-(2-hydroxy phenyl)-2-propen-1-one (PHPO), 3-(1-naphthyl)-1-(2-hydroxy phenyl)-2-propen-1-one (NHPO) and 3-(3,4-dimethoxy phenyl)-1-(2-hydroxy phenyl)-2-propen-1-one (DMPHPO) have been synthesized and characterized by analytical, conductivity, thermal, magnetic, infrared, electronic and electron spin resonance data. Based on analytical data the stoichiometry of the complexes has been found to be 1 : 2. The conductivity data show that all these complexes are non-electrolytes. The infrared spectral data indicate that the ligand PHPO acts as uninegative tridentately towards Co(II) and Ni(II) and bidentately with Cu(II), Zn(II) and Cd(II). Ligands like NHPO and DMPHPO act as uninegative bidentately with all the metal ions. The electronic spectral data suggest that all the Co(II) complexes and Ni(II) of PHPO complex are octahedral and all the Cu(II) and Ni(II) of NHPO and DMPHPO complex are square-planar. The complex of Zn(II) and Cd(II) are tetrahedral. ESR parameters of Cu(II) complexes have been calculated and relevant conclusions have been drawn with respect to the nature of bonds present in them.     

Chlorofluorieren mit Trifluormethylhypochlorit CF3OCl. Darstellung und spektroskopische Charakterisierung von Trifluormethyliodchloridfluorid CF3I(Cl)F

Chlorofluorinate with Trifluoromethylhypochlorite CF₃OCl. Preparation and Spectroscopic Characterization of Trifluormethyliodinechloridefluoride CF₃I(Cl)F The preparation of a new iodine(III) compound, trifluormethyliodinechloridefluoride CF₃I(Cl)F, via oxidative addition of trifluoromethylhypochlorite CF₃OCl to trifluoromethyliodide CF₃I is described. The thermolabile compound has been characterized by i.r., Raman, ¹⁹F NMR, and mass spectroscopy.     

5,10,15,20-四(对氯苯基)卟啉羟基稀土配合物的光谱研究

研究了四(对氯苯基)卟啉及其羟基稀土配合物的紫外-可见光谱、红外光谱和拉曼光谱,对主要谱带进行了经验归属,讨论了中心离子对紫外光谱和共振拉曼光谱结构敏感带频率的影响.     

Derivate von Tricyanmethan. 2. Untersuchungen über Methyltricyanmethan (1,1,1-Tricyanethan) [1]

Derivatives of Tricyanomethane. 2. Studies on Methyl Tricyanomethane (1,1,1-Tricyanoethane) The title compound H₃C? C(CN)₃ has been characterized by means of nuclear magnetic resonance, vibrational, and mass spectra.     

Diffuse reflection FTIR spectral database of dyes and pigments

24 pigments commonly used in art have been characterized by diffuse reflection infrared spectroscopy (DR). All of the compounds have also been characterized by means of infrared absorption spectroscopy to demonstrate the reliability of the DR technique. This is the first record of the use of this technique as an analytical tool in conservation science, and the results appear to be promising for the identification of unknown pigments used on historical and artwork artifacts. Although the DR technique used here is not nondestructive, it can still be usefully applied to the analysis of artwork since it requires only a very small quantity of sample for analysis.     

The role of TiO2 in the B2O3–Na2O–PbO–Al2O3 glass system

Optical and vibrational studies have been carried out on 60B₂O₃·(20−x)Na₂O·10PbO·10Al₂O₃:xTiO₂ (x=0, 1, 2, 3, 4, and 5 mol%) glasses, in order to understand the role of TiO₂ in the 60B₂O₃·20Na₂O·10PbO·10Al₂O₃ glass matrix. The X-ray patterns reveal homogeneous glasses over the entire compositional range. The absorption spectra show that the energy of the optical band gap (ΔE_opt) and Urbach's energy (E_U) decreases as TiO₂ content increases. The changes observed in the Raman and IR spectra are related to the BO₄→BO₃ back conversion effect and the appearance of “loose” BO₄⁻ groups. The data indicate that titanium ions act as a network modifier.     

Dinitramide and its salts

The vibrational and electronic spectra of dinitramide salts MN(NO₂)₂ (M=K, Na, Li, NH₄, Fe, Ag, Mn, Mg, Rb, C(NH₂)₃) have been studied. The IR and Raman spectra of solutions and melts of the salts have been satisfactorily interpreted on the basis of the anion model withC _2v symmetry. The complication of the spectra in the crystalline phase has been explained by restructurization of the anion that reduces its symmetry and makes the nitro groups nonequivalent.For part 6, seeIzv. Akad. Nauk, Ser. Khim., 1995, 113 [Russ. Chem. Bull.,44, 108 (Engl. Transl.)].Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 8, pp. 1508–1512, August, 1995.     

Preparation and investigation of the crystals formed in the buckminsterfullerene-tetraselenotetracene-carbon disulfide system

Crystals containing up to 30 wt. % CS₂, according to the data of IR and X-ray photoelectron spectroscopy, were isolated from the C₆₀-TSeT-CS₂ (TSeT is tetraselenotetracene) system. The unusually high concentration of carbon disulfide results in the complete sublimation of the crystals at a relatively high temperature (520 °C). The electron energy loss spectra of the crystals obtained were measured and analyzed.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 5, pp. 845–848, May, 1995.This work was financially supported by the Russian Foundation for Basic Research (Projects No. 93-03-18002, 93-03-18705, and 93-03-5650).