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混合固态铕铽配合物的荧光研究 总被引:6,自引:1,他引:5
由邻苯二甲酸氢钾,2,2’-联吡啶分别与EuCl3和TbCl3在乙醇水溶液中反应,合成了铕配合物Eu2L3L’和铽配合物Tb2L3L’(L=邻苯二甲酸根,L’=2,2’联吡啶);以不同摩尔比混合两种配合物,经机械研磨,得混合固体铕铽配合物。测试了配合物的荧光光谱及红外光谱,结果表明,与单一铕配合物和铽配合物相比,混合固态配合物无论是荧光发射峰位还是荧光强度均发生了明显变化,铽对铕的荧光强度有敏化作 相似文献
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用紫外光谱研究了等离子点时1:1Co(Ⅱ)-HSA配合物金属中心的结构,结果表明:该配合物的中心钴在低浓度时以Co(Ⅱ)和Co(Ⅲ)两种氧化态共存,高浓度时(>3.0×10-4mol·L-1)仅以Co(Ⅲ)氧化态存在;且金属中心随着浓度增大发生"八面体→四方锥→四方平面"的构型变化。与生理pH时金属中心的结构存在显著差别,可用pH效应加以解释。 相似文献
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双亲性席夫碱金属配合物LB膜的制备和结构特征 总被引:1,自引:0,他引:1
合成了双亲性席夫碱配体与Zn^2+,Cd^2+的配合物,用元素分析,红外光谱和紫外光谱对配合物进行了鉴定,以L-B技术得到了层状有序多层膜。LB膜的紫外可见吸收光谱表明膜中分子形成了H-聚集体,且具有特定取向,该膜在紫外光的照射下,膜内配体分子发生的烯醇-醌式结构转变能够提高分子的非线性极化率,该结果有利于这类配合物薄膜材料非线性光学性质研究。 相似文献
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PF—吐温—80分光光度法测定钼的方法研究 总被引:3,自引:0,他引:3
在0.05-0.4mol.L^-1盐酸溶液中,吐温-80存在下,钼与苯基萤光酮生成橙色配合物,在该配合物的第二吸收峰测量,其表观摩尔吸光系数ε=1.1×10^4L.mol^-1.cm^-1,测得配合物组成比为Mo=PF=1:1。在25mL溶液中含钼0-8μg范围时遵守比耳定律。有色配合的稳定6h以上。此法用于矿石中微量钼的测定,结果令人满意。 相似文献
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氨基葡萄糖及羧甲基氨基葡萄糖与铁(Ⅱ)、锌(Ⅱ)、钴(Ⅱ)、铜(Ⅱ)配合物的光谱特征 总被引:14,自引:1,他引:13
本文研究了氨基葡萄糖及羧甲基氨基葡萄糖分别与铁(Ⅱ)、锌(Ⅱ)、钴(Ⅱ)、铜(Ⅱ)形成配合物的UV,IR和^1H-NMR光谱特征。配合物紫外的λmax发生了明显紫移;在IR谱中,配合物的面外振动峰655cm^-1较未配位的氨基葡萄糖中的面外振动峰670cm^-1低,且在990cm^-1附近出现新的吸收峰;在^1H-NMR谱中,配合物C3上羟基中的质子化学位移较未配位的均移向高场,氨基上质子的化学位移较未配位的也移向高场,其他碳上羟基中的质子化学位移值不变,从而初步证实了配合物中的氨-金属(N-M)键的形成。本文还研究了羧甲基氨基葡萄糖及其与铁(Ⅱ)、钴(Ⅱ)、铜(Ⅱ)配合物的合成。其配合物的IR谱线较未配位的IR谱线并没增多,指出这种反常现象是糖环的刚性所致。它们的IR和UV光谱均证实了分子中不存在游离的羰基峰,并证实了它们分子中内盐的存在,配合物的IR谱中出现新的一组吸收峰:433.1和408.9cm^-1(O-Fe),507.1和495.0cm^-1(O-Co),403.1和389.0cm^-1(O-Cu),证实了配合物中的氧-金属键(O-M)的形成。 相似文献
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Co(1,10-phen·)32+-KIO4-鲁米诺化学发光体系与应用 总被引:2,自引:0,他引:2
本文研究了Co(1,10-phen·)32+配合物对KIO4氧化鲁米诺所产生的强化学发光反应.以1,10-phen·为配位体时,Co(Ⅱ)的检出限为8×10-8g/L,工作曲线响应浓度范围在1×10-6~1×10-4g/L,测定1×10-4g/LCo(Ⅱ)离子的相对标准偏差为2.5%.配合物化学发光法检测啤酒、维生素B12针剂中微量Co(Ⅱ)可获得满意结果. 相似文献
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本文合成了一种新的含硫希夫碱 :香兰素缩硫代肼酸苄酯 (HL) ,及其配合物CoL2 DEA ,并通过紫外—可见及红外光谱对该配合物的分子结构进行了研究 ,推断出该三元配合物的配位情况。采用计算机辅助二次回归正交设计 ,系统地研究了该三元配合物在 95%乙醇溶液中的最佳显色条件 (包括反应温度 ,加热时间 ,及各反应物浓度等五个因素 )。根据二次回归方程 ,用步长加速法计算出该体系的最大吸光度及其相应五个因素的最佳显色取值 ,并通过实验验证了计算结果的准确性。试验了干扰离子及其消除方法 ,并将该配合物用于药物华素片及VB12针剂中含钴量的测定 ,获得了满意的结果 ,建立了测定Co(Ⅱ )的新方法。该体系最大吸收波长为 4 0 4 0nm ,ε40 4max=5 2 9× 10 4L·mol-1 ·cm-1 ,检测限为 0~ 2 0 μg·( 2 5mL) -1 ,配合物组成比为 1∶2∶1。 相似文献
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Hu Z Wu H Haverkort MW Hsieh HH Lin HJ Lorenz T Baier J Reichl A Bonn I Felser C Tanaka A Chen CT Tjeng LH 《Physical review letters》2004,92(20):207402
Using soft-x-ray absorption spectroscopy at the Co L(2,3) and O K edges, we demonstrate that the Co3+ ions with the CoO5 pyramidal coordination in the layered Sr2CoO3Cl compound are unambiguously in the high spin state. Our result questions the reliability of the spin state assignments made so far for the recently synthesized layered cobalt perovskites and calls for a reexamination of the modeling for the complex and fascinating properties of these new materials. 相似文献
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The reaction of nitric oxide with ZSM-5 zeolite ion-exchanged by Co(II) (Co-ZSM-5) has been studied by electron spin resonance (ESR), Fourier transform infrared (FTIR) and diffuse reflectance ultraviolet-visible spectroscopy. When dehydrated Co-ZSM-5 reacts at room temperature with nitric oxide, the ESR spectrum of Co(II) atg = 5.5, which is only observable below 45 K, is greatly reduced and a new59Co hyperfine octet forms at gavg = 2.11. The overall Co(II) ESR intensity decreases by about 50% which suggests formation of some diamagnetic cobalt complex. Mononitrosyl cobalt complexes such as Co(I)-NO+ or less probably Co(III)-(NO)− are suggested as possible precursors of a dintrosyl cobalt complex. The octet indicates hyperfine interaction with59Co and is associated with a cobalt dinitrosyl complex. FTIR bands at 1813 and 1896 cm−1 confirm a dinitrosyl species and a broad band from 1600–1800 cm−1 is tentatively interpreted as a mononitrosyl species. The visible spectrum for dehydrated Co-ZSM-5 shows a tetrahedral Co(II) band from 500–700 nm with three components which disappears after NO adsorption at room temperature. We suggest that Co(0)-(NO)22+ forms after NO adsorption onto Co(II)-ZSM-5 zeolite on the basis of ESR and ultraviolet-visible spectroscopy. 相似文献
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利用基于密度泛函的第一性原理的计算方法,研究了Co单掺及Co和Zn共掺LiNbO_3晶体的电子结构和吸收光谱.研究显示,各掺杂体系铌酸锂晶体的带隙均较纯铌酸锂晶体变窄. Co:LiNbO_3晶体禁带宽度为3.32 eV; Co:Zn:LiNbO_3晶体, Zn的浓度低于阈值或达到阈值时,禁带宽度分别为2.87或2.75 eV. Co:LiNbO_3晶体在可见-近红外光波段2.40, 1.58, 1.10 eV处形成吸收峰,这些峰归结于Co 3d分裂轨道的跃迁;加入抗光折变离子Zn~(2+),在1.58, 1.10 eV处的吸收峰增强,可以认为Zn~(2+)与Co~(2+)之间存在电荷转移,使e_g轨道电子减少,但并不影响t_(2g)轨道电子.结果表明,晶体中的Co离子在不同共掺离子下可充当深能级中心(2.40 eV),或可充当浅能级中心(1.58 eV),两种情况下,掺入近阈值的Zn离子均有助于实现优化存储. 相似文献
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Prosnikov M. A. Molchanova A. D. Dubrovin R. M. Boldyrev K. N. Smirnov A. N. Davydov V. Yu. Balbashov A. M. Popova M. N. Pisarev R. V. 《Physics of the Solid State》2016,58(12):2516-2522
Physics of the Solid State - The results are presented on phonon excitations and the electronic structure of Co2TiO4 inverse spinel in which magnetically ordered cobalt ions Co2+ (3d 7) are in... 相似文献
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The paper presents results of computations of the energy efficiency of the cobalt luminescence in ZnSe:Co determined by the
photoacoustic method. The transmission spectra, photoacoustic experimental and theoretical spectra, and the frequency dependence
on the photoacoustic amplitude characteristics are presented. From them, the energy efficiency of Co2+ the near infrared luminescence (3200 nm) was computed in the frame of new proposed photoacoustic model of computations of
the luminescence energy efficiency. 相似文献
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H.Y. Kang H. Paul Wang W.-K. Lin I-W. Sun C.-J.G. Jou U-Ser Jeng S.G. Chang 《Journal of Electron Spectroscopy and Related Phenomena》2012
Nanostructured cobalt is one of the key elements in catalysis and therapeutic drug delivery. To design and prepare nanosize-controllable cobalt, a better understanding of its growth mechanism is essential. Growth of Co nanoparticles encapsulated in carbon-shell (Co@C) during temperature-programmed carbonization of the Co2+-β-cyclodextrin (CD) complex at 363–573 K was, therefore, studied by in situ synchrotron small-angel X-ray scattering and X-ray absorption near edge structure spectroscopy. The carbon-shell having a thickness of about 2 nm can prevent the core Co from being aggregated and oxidized. A relatively slow reduction of Co(II) to Co is observed at 393–423 K (stage I) prior to a particle growth transition-state possessing Co of 2.2 nm in diameter at 423–483 K. At 483–513 K (stage II), an increasing Co(II) reduction rate coupled with a rapid fusion and coalescence of Co nanoparticles is found. The average growth rates of Co at stages I and II are about 27 and 98 atoms/min, respectively. The most-probable particle diameter of the ripened Co is 5.9 nm. The carbon-shell can be removed by steam reforming to yield the Co nanoparticles. This work also exemplifies the possible temperature-controllable growth of Co@C, especially in the Co size range of 2–6 nm in diameter. 相似文献
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Two novel, mixed ligand complexes of cobalt(III) and nickel(II), [Co(phen)2(taptp)]3+ (1) and [Ni(phen)2(taptp)]2+ (2) (phen = 1,10-phenanthroline and taptp = 4,5,9,18-tetraazaphenanthreno [9,10-b]triphenylene), were synthesized and characterized by elemental analyses, UV-visible and NMR spectroscopies. The binding interactions of the two complexes with DNA have been investigated using absorption and emission spectroscopy methods and electrophoresis measurement mode. The intrinsic binding constants for these complexes to DNA are in the order of 105. In Tris buffer, the Co(III) complex shows a moderate luminescence which was enhanced after binding to DNA. However for complex Ni(II), no emission was observed in Tris buffer. The [Co(phen)2(taptp)]3+ and [Ni(phen)2(taptp)]2+ can cause the photocleavage of DNA supercoiled pBR322 upon irradiation by 360 nm light. Based on the data, an intercalative mode of DNA binding is suggested for the two complexes. 相似文献
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Ionics - H+ and Co2+ ions co-doped polyaniline were synthesized by cyclic voltammetry onto the stainless steel mesh with various concentrations of cobalt chloride (CoCl2 · 6H2O) in... 相似文献