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141.
Novel Tb/acetylacetone (acac)/poly (acrylic acid) (PAA) composite nanoparticles were successfully synthesized using the ultrasonic method. The nanoparticles are water soluble, stable and have extremely narrow emission bands and high internal quantum efficiencies. They were used as fluorescence probes in the determination of ascorbic acid (Vc) based on the fluorescence quenching of nanoparticles in the presence of ascorbic acid. The method is based on the complexation between ascorbic acid and nanoparticles in the absence of the oxidant. The influence of different buffers and concentration of the nanoparticles on the relative fluorescence intensity was tested, and Tris-HCl buffer solution proved to be the best. Under the optimum conditions, a liner calibration graph was obtained over the Vc concentration range of 0.05–10 µg mL−1. The corresponding detection limit is 0.008 µg mL−1 and the relative standard deviation is 1.4% for 0.5 µg mL−1 (n=7). The method proved to be simple, rapid, and specific, and the recovery and relative standard deviation are very satisfactory. A mechanism explaining the process is also presented. 相似文献
142.
The luminescence properties of aluminate sodalite Ca8[Al12024](WO4)2 (CAW) undoped and doped with Th^3 are reported and discussed. At room temperature the emission of tetrahedral WO4^2- in CAW showed an abnormally small Stokes shift (9060 cm^-1), which is related to the crystal structure of CAW. A strong absorption band in the excitation spectrum of the Th^3 -activated CAW is ascribed to the absorption of the charge transfer state Th^4 -W^5 , into which the excitation resulted in the efficient emission from the ^5D4 level of Tb^3 , but not from the ^5D3 level. 相似文献
143.
Studies on the energy transfer system of terbium-norfloxacin chelate and its interaction with serum albumins 总被引:1,自引:0,他引:1
XU Yan SHEN Han-Xi Department of Chemistry Nankai University Tianjin ChinaHUANG Han-Guo Department of Chemistry Engineering Hebei Institute of Technology Tangshan Hebei China 《中国化学》1997,15(2):138-143
The energy absorbed by norfloxacin could be transferred to terbium(Ⅲ) through chela-tion of norfloxacin with terbium(Ⅲ),then the characteristic fluorescence emission could be observed.The interaction of serum albumins with norfloxacin have been investigated in this paper.The results showed that HSA could inhibit the energy transfer between norfloxacin and terbium(Ⅲ).But,BSA could not.It was shown that the binding properties of norfloxacin to HSA and BSA were totally different. 相似文献
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庚二酸·邻菲啰啉合铽配合物的合成与晶体结构 总被引:1,自引:0,他引:1
用水热技术合成了配位高聚物[Tb(Hpim)(pim)(phen)]n·1.5nH2O,并通过元素分析、红外光谱和单晶X射线衍射技术确定了其组成和晶体结构.此晶体属三斜晶系,空间群为P墿,晶胞参数a=1.1049(6)nm,b=1.1608(7)nm,c=1.2557(7)nm,α=110.590(9)°,β=99.999(10)°,γ=110.775(8)°;V=1.3252(13)nm3;Z=2;R=0.0492,wR=0.1036.配合物单元通过氢键及邻菲啉之间的芳环堆积效应构筑成纳米链结构并组装成三维超分子结构. 相似文献
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Terbium p-chlorobenzoate complex with 1,10-phenanthroline, [Tb(p-ClBA)3(phen)]2(1) has been obtained in the ethanol solution, where p-ClBA=p-chlorobenzoate and phen=1,10-phenanthroline. It crystallizes in the triclinic system, space group P1, a=1.008 1(2) nm, b=1.185 7(2) nm, c=1.431 1(3) nm, α=110.826(4)°, β=96.436(4)°, γ=101.737(4)°, Z=2. The two Tb(III) ions are linked by four carboxylate groups through their bidentate bridging modes, forming a dimeric unit with crystallographic inversion center. Each terbium ion has an eight-coordinate geometry with four of the coordination sites occupied by four oxygen atoms from the four bridging carboxylates, respectively, two oxygen atoms from bidentate carboxylate, and the remaining positions occupied by two nitrogen atoms from a 1,10-phenanthroline molecule. The Tb(III) ion adopt a distorted square antiprism coordination geometry. The excitation and luminescence data observed at room temperature show that the title complex emits very intensive green fluorescence under ultraviolet light. The result of thermal analysis indicates the complex [Tb(p-ClBA)3(phen)]2 is quite stable to heat. CCDC: 221921. 相似文献
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