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141.
Binding constant determination of uranyl–citrate complex by ACE using a multi‐injection method 下载免费PDF全文
Yiding Zhang Linnan Li Hexiang Huang Linnan Xu Ze Li Yu Bai Huwei Liu 《Electrophoresis》2015,36(7-8):1033-1039
The binding constant determination of uranyl with small‐molecule ligands such as citric acid could provide fundamental knowledge for a better understanding of the study of uranyl complexation, which is of considerable importance for multiple purposes. In this work, the binding constant of uranyl–citrate complex was determined by ACE. Besides the common single‐injection method, a multi‐injection method to measure the electrophoretic mobility was also applied. The BGEs used contained HClO4 and NaClO4, with a pH of 1.98 ± 0.02 and ionic strength of 0.050 mol/L, then citric acid was added to reach different concentrations. The electrophoretic mobilities of the uranyl–citrate complex measured by both of the two methods were consistent, and then the binding constant was calculated by nonlinear fitting assuming that the reaction had a 1:1 stoichiometry and the complex was [(UO2)(Cit)]?. The binding constant obtained by the multi‐injection method was log K = 9.68 ± 0.07, and that obtained by the single‐injection method was log K = 9.73 ± 0.02. The results provided additional knowledge of the uranyl–citrate system, and they demonstrated that compared with other methods, ACE using the multi‐injection method could be an efficient, fast, and simple way to determine electrophoretic mobilities and to calculate binding constants. 相似文献
142.
143.
Vincent Chaleix 《Tetrahedron letters》2007,48(4):703-706
Efficient synthetic routes for preparation of a new family of aldehyde-bisphosphonate conjugates were presented. These compounds appeared as promising intermediates for incorporation of bisphosphonate moiety in various substrates under mild conditions. We report here a first application to the synthesis of a series of three phosphonated tripods designed for actinides chelation therapy. 相似文献
144.
采用周期性密度泛函理论研究羟基化α-石英(101)面的铀酰离子吸附行为. 通过对铀酰离子的水合作用考虑水溶剂对结构的短程溶剂化效应,并通过类导体屏蔽模型(COSMO)考虑水溶剂对结构的远程溶剂化效应. 吸附能计算结果和电子结构数据均表明水合铀酰离子吸附构型比氢氧化铀酰吸附构型稳定,并且在液相中两种类型的稳定吸附位均为dia-Os1Os2位. 两种形式在电子结构上有很大的差异,主要是由于铀与表面作用后成键强弱程度不同,使5f 轨道宽化和略微红移存在差异. 在铀酰离子吸附的基础上利用卤素离子改变铀酰离子配位环境可调整体系的带隙. 相似文献
145.
Evgeny V. Nazarchuk Oleg I. Siidra Dr. Sergey V. Krivovichev Thomas Malcherek Wulf Depmeier 《无机化学与普通化学杂志》2009,635(8):1231-1235
Two new mixed alkaline uranyl molybdates CsNa3[(UO2)4O4Mo2O8] ( 1 ) and Cs2Na8[(UO2)8O8(Mo5O20)] ( 2 ) have been obtained by high‐temperature solid state reactions. Their crystal structures have been solved by direct methods: Compound 1 : triclinic, P , a = 6.46(1), b = 6.90(1), c = 11.381(2) Å, α = 84.3(1), β = 91.91(1), γ = 80.23(1)°, V = 488.6(2) Å3, R1 = 0.06 for 2865 unique reflections with |Fo| ≥ 4σF; Compound 2 : orthorhombic, Ibam, a = 6.8460(2), b = 23.3855(7), c = 12.3373(3) Å, V = 1975.2(1) Å3, R1 = 0.049 for 2120 unique reflections with |Fo| ≥ 4σF. The structure of 1 contains complex sheets of UrO5 pentagonal bipyramids and molybdenum polyhedra. The sheets have [(UO2)2O2(MoO5)] composition. Natrium and cesium atoms are located in the interlayer space. Cesium atoms are situated between the molybdenum clusters, whereas natrium atoms are segregated between the uranyl complexes. The large Cs+ ions are localized between the Mo2O9 groups and force the molybdenum polyhedra to rotate relative to the [(UO2)2O2(MoO5)] sheets. Such rotation is impossible for U6+ polyhedra due to their rigid edge‐sharing complexes. The distance between the U6+ polyhedra vertices of neighboring layers is 3.8 Å, that allows the Na+ ion to be positioned between the uranyl groups. The crystal structure of 2 is based upon a framework consisting of [(UO2)2O2(MoO5)] sheets parallel to (010). The sheets are linked into a 3‐D framework by sharing vertices with the Mo(2)O4 tetrahedra, located between the sheets. Each MoO4 tetrahedron shares two of its corners with two MoO6 octahedra in the sheet above, and the other two with MoO6 octahedra of the sheet below. Thus four MoO6 octahedra and one MoO4 tetrahedron form chains of composition Mo5O18. The resulting framework has a system of channels occupied by the Cs+ and Na+ ions. 相似文献
146.
Jeremy Petit Valérie Geertsen Catherine Beaucaire Moncef Stambouli 《Journal of chromatography. A》2009,1216(18):4113-4120
Nuclear energy development has raised new issues like radionuclides biogeochemistry. The modelling of their biochemical properties involves the accurate determination of thermodynamical data, like stability constants. This can be achieved by using hyphenated capillary electrophoresis (CE)–ICPMS and the method was applied successfully on 1:1 lanthanum–oxalate and uranyl–oxalate complexes. Several significant steps are discussed: choice of analytical conditions, electrophoretic mobility calculation, mathematical treatment of experimental data by using linear regressions, ligand concentration and ionic strength corrections. The following values were obtained with a good precision for lanthanum–oxalate and uranyl–oxalate complexes: log(K°(LaOxa+)) = 6.10 ± 0.10 and log(K°(UO2Oxa)) = 6.40 ± 0.30, respectively, at infinite dilution. These values are consistent with the literature data, showing CE–ICPMS potential for metal complexes stability constants determination. 相似文献
147.
The crystals of four amine‐templated uranyl oxoselenates(VI), [C3H12N2][(UO2)(SeO4)2(H2O)2](H2O) ( 1 ), [C5H16N2]2[(UO2)(SeO4)2(H2O)](NO3)2 ( 2 ), [C4H12N][(UO2)(SeO4)(NO3)] ( 3 ), and [C4H14N2][(UO2)(SeO4)2(H2O)] ( 4 ) were prepared by evaporation from aqueous solution of uranyl nitrate, selenic acid and the respective amine. The crystal structures of all four compounds have been solved by direct methods from X‐ray diffraction data. The structure of 1 (triclinic, , a = 7.5611(16), b = 7.7650(17), c = 12.925(3) Å, α = 94.605(18), β = 94.405(17), γ = 96.470(17)°, V = 748.8(3) Å3, R1 = 0.029 for 2769 unique observed reflections) is based upon 0D‐units of the composition [(UO2)2(SeO4)4(H2O)4]4?. These discrete units are composed from two pentagonal [UO7]8? bipyramids linked via [SeO4]2? tetrahedra and are unknown in structural chemistry of uranium so far. The structure of 2 (monoclinic, C2/c, a = 28.916(5), b = 8.0836(10), c = 11.9856(16) Å, β = 110.909(11)°, V = 2617.1(6) Å3, R1 = 0.035 for 2578 unique observed reflections) contains [(UO2)(SeO4)2(H2O)]2? chains of corner‐sharing pentagonal [UO7]8? bipyramids and [SeO4]2? tetrahedra. The chains run parallel to the c axis and are arranged into layers parallel to (100). In the structure of 3 (monoclinic, C2/m, a = 21.244(5), b = 7.1092(11), c = 8.6581(18) Å, β = 97.693(17)°, V = 1295.8(4) Å3, R1 = 0.027 for 1386 unique observed reflections), pentagonal [UO7]8? bipyramids share corners with three [SeO4]2? tetrahedra each and an edge with a [NO3]? anion to form [(UO2)(SeO4)(NO3)]? chains parallel to the b axis. In the structure of 4 (triclinic, , a = 6.853(2), b = 10.537(3), c = 10.574(3) Å, α = 99.62(3), β = 94.45(3), γ = 100.52(3)°, V = 735.6(4) Å3, R1 = 0.045 for 2713 unique observed reflections), one symmetrically independent pentagonal [UO7]8? bipyramid shares corners with four [SeO4]2? tetrahedra to form the [(UO2)(SeO4)2(H2O)]2? chains parallel to the a axis. A comparison to related uranyl compounds is given. 相似文献
148.
The first crystal structures of complexes of tetrahydroxy-[3.1.3.1]metacyclophanes, also termed homocalix[4]arenes, are reported. In the two uranyl ion complexes obtained, with different para-substituents, the complex core is analogous to that in tetrahomodioxacalix[4]arene complexes, with the cation in a tetra-phenoxide, distorted square-planar environment. The packing in one of these complexes comprises two different arrangements, one of them being a columnar stacking of complex molecules with sandwiched triethylammonium counter-ions hydrogen bonded to one complex and held by cation–π and CH–π interactions within the cavity of the other neighbouring one. 相似文献
149.
应用相对论密度泛函理论系统研究了水溶液中非水合化和水合化碳酸铀酰化合物Cn/m(其中n和m分别为结构中碳酸配体和水配体的个数)的结构.溶剂效应采用类导体屏蔽模型(COSMO),并采用零级规整近似(ZORA)方法考虑标量相对论效应和旋-轨耦合相对论效应.电子跃迁采用包含旋-轨耦合相对论效应的含时密度泛函理论并在相关交换势中采用轨道势能统计平均(SAOP)做近似计算.结果表明碳酸配体对配合物结构和电子跃迁有很大的影响.C3/0配合物的稳定性可归于5f轨道参与了高占据轨道的成键作用.增加碳酸盐配体导致最大波长的蓝移,并在近可见光区域出现高强度的吸收. 相似文献