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1.
Rb_2CO_3-C_2H_5OH-H_2O三元体系在40℃的溶解度及其应用 总被引:1,自引:0,他引:1
铷和铯是稀有分散的成盐元素 ,以往研究工作甚少 ,近年来铷和铯及其化合物在高新技术中的应用正受到人们的关注[1 ] 。钾、铷和铯的化学性质十分相似 ,尤其是铷与铯的分离和纯化难度很大 ,从矿物、盐卤和地热水资源中分离提取铷和铯的过程中 ,通常很难获得纯度较高的产品 ,开展铷盐纯化技术的研究具有重要的实际意义。混合溶剂用于盐类的分离和纯化 ,一直受到重视。文献[2 ] 中仅报道了对碱金属碳酸盐 醇 水在 2 0℃时两相的分层关系 ,没有研究过饱和状态下的三相关系。根据碳酸铯在 30℃乙醇中的溶解度比碳酸铷大 5倍以上 ,我们采用国产… 相似文献
2.
铷和铯是稀有分散的成盐元素,以往研究工作甚少,近年来铷和铯及其化合物在高新技术中的应用正受到人们的关注^[1]。钾、铷和铯的化学性质十分相似,尤其是铷与铯的分离和纯化难度很大,从矿物、盐卤和地热水资源中分离提取铷和铯的过程中,通常很难获得纯度较高的产品,开展铷盐纯化技术的研究具有重要的实际意义。混合溶剂用于盐类的分离和纯化,一直受到重视。文献^[2]中仅报道了对碱金属碳酸盐-醇-水在20℃时两相的分层关系,没有研究过饱和状态下的三相关系。根据碳酸铯在30℃乙醇中的溶解度比碳酸铷大5倍以上,我们采用国产碳酸铷商品作为试验物料,在测定了40℃时Rb2CO3-C2H5OH-H2O三元体系平衡溶解度相关系的基础上,进行简单的纯化处理,使该产品纯度得到进一步提高。 相似文献
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利用淋洗法测定铷、铯在Zerolit FF(硝酸根式)树脂和甲醇或丁醇与硝酸的混合溶剂间的分配系数;初步拟定用70%甲醇-30%4.78M硝酸为淋洗液分离示踪量铯和丝克量铷的阴离子树脂交换方法. 相似文献
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四苯硼酸盐为活性物质的PVC膜对金属离子的选择性同溶剂的性质相关。本文考察了以邻硝基苯辛醚(o-NPOE)、邻苯二甲酸二正辛酯(DOP)及癸二酸二丁酯(DBS)为溶剂的四苯硼酸盐PVC膜对金属离子的选择性,比较了四苯硼钠(NaTPB)、四苯硼钾(KTPB)、四苯硼铷(RbTPB)及四苯硼铯(CsTPB)等几种碱金属的四苯硼酸盐为活性物质的膜的电化学性能,研制了以o—NPOE为溶剂,NaTPB为活性物质 相似文献
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火焰原子吸收光谱法测定高纯氯化铷中锂钠钾铯 总被引:2,自引:0,他引:2
张嫦 《理化检验(化学分册)》2003,39(8):498-498,502
铷是一种稀有的碱金属元素,它在自然界中储量很小且极其分散,它的化合物种类也不如其它碱金属元素多、稳定性高。氯化铷是极重要的基本铷盐,它是一种白色结晶性粉末,可用作特种分析试剂、水生物养殖场的人造海水添加剂以及制造金属铷和其它铷盐的原料。铷因其特性而在自然界中易与其它杂质特别是碱金属元素附生,制备时不易纯化。准确检测高纯度氯化铷中主要杂质的含量具实用意义。本文采用火焰原子吸收光谱法测定了高纯度氯化铷中锂钠钾铯的含量,检测灵敏度高、检测成本低,操作简便、快速。 相似文献
7.
碱金属离子的纸电泳分离已有不少方法[1-3]。Alberti等[4]曾用磷酸锆离子交换纸在盐酸介质中电泳分离钾、铷和铯。本文作者考虑到磷钼酸铵作为离子交换剂对碱金属离子具较高的选择性[5,6],故将磷钼酸铵固定在滤纸上作成离子交换纸,以硝酸铵和硝酸为电解质溶液对钾、铷和铯的电泳行为进行研究。 相似文献
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LEI Hong LI Shu-Ni ZHAI Quan-Guo ZHANG Hui-Ying JIANG Yu-Cheng HU Man-Cheng 《物理化学学报》2012,28(7):1599-1607
系统研究了1,2-丙二醇+MCl (M=Na, K, Rb, Cs)+H2O三元体系在298.15 和308.15 K时的等温相平衡. 采用硝酸汞滴定法测定了体系中无机盐的含量, 采用安东帕RXA170 折光率仪及DMA4500 密度计测定了所有体系的折光率和密度数值. 报道了1,2-丙二醇质量分数从0增加到0.9过程中饱和及不饱和三元溶液体系的等温溶解度、密度和折光率数据. 实验结果发现, 随着1,2-丙二醇的不断加入, 饱和溶液的溶解度和密度均呈现出减小的趋势, 而折光率的变化则呈现出相反的趋势. 采用经验方程关联了不同醇水比条件下不饱和溶液的密度和折光率实验数据, 获得了较为理想的拟合结果. 本研究的开展充实了碱金属盐在混合溶剂中的热力学数据, 为相关溶液化学研究奠定了基础. 相似文献
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Conclusions The solubility of sodium, ammonium, potassium, rubidium, and cesium tetraphenylborates in acetone, water, and their mixtures was studied at 25°. The solubility of lithium tetraphenylborate was determined in acetone and water. The solubility in a mixed solvent passes through a maximum for all the salts.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 6, pp. 1170–1173, June, 1968. 相似文献
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An extraction chromatographic method to separate rubidium and cesium using a nitrobenzene solution of ammonium dipicrylaminate
has been developed. The procedure is used in connection with a concentration-dependent radioisotope distribution method for
determining traces of cesium in rubidium salts. A frontal chromatographic enrichment method to eliminate excess sodium, lithium
and calcium salts has been worked out. The results are compared with the conclusions drawn from the extraction mechanism and
with other separation procedures.
Part VIII of the series “The method of concentration-dependent distribution in the quantitative use of radioisotopes”; for
Part VII, seeChem. Listy, 61 (1967) 440. 相似文献
13.
James L. Dye 《Angewandte Chemie (International ed. in English)》1979,18(8):587-598
Anions of sodium, potassium, rubidium, and cesium are stable both in suitable solvents and in crystalline solids. The latter can be prepared either by cooling a saturated solution or by rapid solvent evaporation. Thermodynamic arguments show that alkali metal anions can probably exist in saturated solutions of the alkali metals in any compatible solvent, but that below saturation, dissociation into the cation and solvated electrons is favored in highly polar solvents such as ammonia. The key to solvent-free salts of the alkali metal anions is stabilization of the cation by incorporation into a suitable crown or cryptand complex. By using such complexes it also appears possible to produce “electride” salts in which the charge of the complexed cation is balanced by a trapped electron. The chemical, electrical, and optical properties of salts of the alkali metal anions and “electrides” could provide useful applications. 相似文献
14.
Zbigniew Florjaczyk Wodzimierz Krawiec Wadysaw Wieczorek Maciej Siekierski 《Journal of Polymer Science.Polymer Physics》1995,33(4):629-635
The conducting properties of solid electrolytes comprising random poly(ethylene oxide-co-propylene oxide) (of 84 : 16 monomer units mole ratio) and lithium, sodium, potassium, cesium, and rubidium salts have been studied. The systems containing some lithium or sodium salts achieved conductivity levels as high as 10?5–10?4 S/cm at ambient temperature and greater than 10?3 S/cm at 100°C. However, the systems with rubidium and cesium salts exhibit conductivities a few orders of magnitude smaller. DSC studies show that the electrolytes studied are characterized by a high content of an amorphous phase (95–100%). It is suggested that the copolymer exhibits lower complexing abilities than that of poly(ethylene oxide), which results in a higher flexibility of electrolytes containing small cations and poor dissociation of the salts having large cations. © 1995 John Wiley & Sons, Inc. 相似文献
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Ultraviolet matrix-assisted laser desorption/ionization mass spectrometric (UV-MALDI-MS) analysis of highly acidic, thermally labile species such as glycosaminoglycan-derived oligosaccharides is complicated by their poor ionization efficiency and tendency to fragment through the loss of sulfo groups. We have utilized a systematic approach to evaluate the effect of alkali metal counterions on the degree of fragmentation through SO3 loss from a highly sulfated model compound, sucrose octasulfate (SOS). The lithium, sodium, potassium, rubidium, and cesium salts of SOS were analyzed by UV-MALDI-time-of-flight (TOF)MS using an ionic liquid matrix, bis-1,1,3,3-tetramethylguanidinium alpha-cyano-4-hydroxycinnamate. The positive-ion and negative-ion MALDI mass spectra of five alkali metal salts of SOS were compared in terms of the degree of analyte fragmentation through the SO3 loss and the absolute intensity of a molecular ion signal. Experimental results demonstrate that the lithium, sodium, and potassium salts of SOS undergo some degree of fragmentation through the loss of SO3, whereas the fragmentation through the loss of SO3 in the rubidium and cesium salts of SOS is suppressed. A high detection sensitivity associated with the stability of sulfate half-esters was achieved for the cesium salt of SOS using positive-ion detection. Finally, the cesium salt of chondroitin sulfate A disaccharide was successfully analyzed using UV-MALDI-TOFMS. 相似文献
16.
This paper describes the synthesis and some reactions of potassium, rubidium, cesium and trimethylsilyl carbamoselenothioates. The potassium salts were synthesized in 70–80 % yields by reacting the corresponding thiocarbamoyl chlorides with potassium selenide in acetonitrile. Furthermore, the rubidium and cesium salts were obtained in good yields by treating the trimethylsilyl esters with the corresponding metal fluorides. The crystal structure of acetonitrile‐solvated potassium N,N‐dimethylcarbamoselenothioate consisted of dimeric units, featuring μ‐carbamoselenothioate anions associated with potassium cations that are located on the upper and lower sides of a plane involving two opposing carbamoselenothioate groups. These heavier alkali metal salts readily reacted with alkyl halides to give both S‐ and Se‐alkyl esters. The reaction of the potassium salts with trimethylsilyl chlorides forms S‐ and Se‐trimethylsilyl carbamoselenothioates which are in equilibrium. The reaction of the salts and silyl esters with organo Group‐14 and ‐15 elements halides gave exclusively the corresponding Se‐substituted products in good yields. 相似文献
17.
The analytical reactions of bismuth iodide and stannic chloride with cesium and rubidium are used for the radiochemical separation
of these two elements. The method consists in precipitating potassium, rubidium and cesium as their cobaltinitrites, selective
isolation of cesium as cesium bismuth iodide from glacial acetic acid, and subsequent separation of rubidium from potassium
as chlorostannate from conc. HCl. The results obtained by the present method for the rubidium and cesium contents of the different
U.S.G.S. standard rock samples are compared with those reported using methods of comparable accuracy. The suitability of the
method for the analysis of fall-out samples for their radiocesium (137Cs) contents has been demonstrated. 相似文献
18.
In an attempt to probe a potential template role of the large alkali-metal cations rubidium and cesium in the organization of biorelevant ligands, salicylate and anthranilate complexes of the two elements were prepared and structurally investigated. The studies were also expected to show the marked structural differences compared to the corresponding thallium(I) compounds. Rubidium anthranilate and cesium salicylate could be crystallized as the monohydrates Rb(Anth)(H(2)O) and Cs(Sal)(H(2)O). Both have layer structures containing the cations and the polar groups of the ligands in core domains sandwiched by the aromatic rings above and below. The metal atoms have coordination numbers 7 and 8, respectively, with an irregular coordination sphere made up exclusively of oxygen atoms. Crystalline material with a 1:2 stoichiometry, Cs[H(Anth)(2)], is obtained from aqueous solutions of Cs(Anth) upon absorption of carbon dioxide with concomitant formation of cesium bicarbonate, Cs(HCO(3)). The crystal structure of Cs(HCO(3)) was redetermined to obtain precise benchmark data for cesium carbonates and carboxylates. The cesium hydrogen bisanthranilate also has a layer structure with eight-coordinate cesium atoms. The coordination sphere includes one nitrogen donor atom. The organization of all layer structures appears to be governed mainly by steric effects and electrostatic forces with very little directional influence of the cations. This result suggests that the large alkali metals have no efficient template effect for the organization of biological substrates and can explain the low toxicity of rubidium and cesium salts. 相似文献
19.
We have shown that the presence of other alkali metal alkoxides in the alkyllithium-initiated polymerization drastically increases the rate of polymerization and vinyl unsaturation in polybutadiene. Mechanistically, the propagating center is the dynamic equilibriums between carbon–metal bonds and oxygen–metal bonds. With potassium, rubidium, and cesium salts it reaches a limiting anionic behavior. 相似文献
20.
Alkali salts of 1-hexyl sulfonate were ionized by laser irradiation and the positive ions were analyzed by time-of-flight mass spectrometry. The sodium, potassium, rubidium and cesium salts produce relatively simple spectra. The major organic ions observed are due to the salt plus a cation or the dimer plus a cation. No molecular or fragment ions were detected. The instrumentation and the method of interpreting these data are described. 相似文献