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91.
Experimental and Computational Studies on the Formation of Thorium–Copper Heterobimetallics 下载免费PDF全文
Pikun Yang Enwei Zhou Dr. Guohua Hou Prof. Guofu Zi Dr. Wanjian Ding Dr. Marc D. Walter 《Chemistry (Weinheim an der Bergstrasse, Germany)》2016,22(39):13845-13849
The formation of actinide–transition metal heterobimetallics mediated by a terminal actinide imido complex was comprehensively studied. The reaction of the thorium imido complex [(η5‐C5Me5)2Th=N(mesityl)(DMAP)] ( 3 ), prepared from [(η5‐C5Me5)2ThMe2] ( 1 ) and mesitylNH2 or [(η5‐C5Me5)2Th(NHmesityl)2] ( 2 ) in the presence of 4‐(dimethylamino)pyridine (DMAP), with copper(I) halides gave the first thorium–copper heterobimetallic compounds [(η5‐C5Me5)2Th(X){N(mesityl)Cu(DMAP)}] (X=Cl ( 4 ), Br ( 5 ), I ( 6 )). Complexes 4 – 6 feature an unusual geometry with a short Th?Cu distance, which DFT studies attribute to a weak donor–acceptor bond from the Cu+ atom to the electropositive Th4+ atom. They are reactive species, as was shown by their reaction with the dimethyl complex [(η5‐C5Me5)2ThMe2] ( 1 ). Furthermore, a comparison between Th and early transition metals confirmed that Th4+ exhibits distinctively different reactivity from d‐transition metals. 相似文献
92.
Ahmed R. Elsalamouny Osman A. Desouky Saad A. Mohamed Ahmed A. Galhoum 《Journal of Dispersion Science and Technology》2017,38(6):860-865
Treatment of aqueous solution contaminated by uranium and thorium using a new Mannich type resin was studied. Different instrumental techniques such as elemental analysis, FTIR, and thermogravimetric analysis were employed for full characterization of the synthetic resin. Adsorption behavior was studied by batch experiments to determine the optimum conditions for U(VI) and Th(IV) ion removal. The adsorption studies showed the best fit with the second order rate equation and Langmuir model. The adsorption process is endothermic, spontaneous, and of increased disorder. The regeneration of sorbent was carried out using diluted HCl and the reuse of sorbent remains appreciable. 相似文献
93.
Prof. Dr. Holger Braunschweig Dr. Mehmet Ali Celik Dr. Klaus Dück Dr. Florian Hupp Dr. Ivo Krummenacher 《Chemistry (Weinheim an der Bergstrasse, Germany)》2015,21(26):9339-9342
The preparation of [3]thoro‐ and [3]uranocenophanes, the first structurally authenticated ansa‐bridged complexes of actinocenes, is reported. Following a flytrap route, 1,2‐bis(cyclooctatetraenyldimethylsilyl)methane was synthesized, reduced to its tetraanion, and subsequently converted into bridged uranocene and thorocene complexes by salt metathesis with the corresponding actinide tetrachlorides. In addition, their electronic structures have been investigated by experimental (UV/Vis spectroscopy, cyclic voltammetry) and theoretical (DFT) methods. 相似文献
94.
Ahmed M. Donia Asem A. Atia Tarik E. Amer Mona N. El-Hazek Mohamed H. Ismael 《Journal of Dispersion Science and Technology》2013,34(11):1673-1681
A glycidyl methacrylate/divinylbenzene resin containing triethylenetetramine functional group was synthesized. The adsorption behavior of the obtained resin toward U(VI), Th(IV), and La(III) in aqueous solutions was investigated by batch and column techniques at different experimental conditions. Kinetic and thermodynamic characteristics of the adsorption process have been investigated. The regeneration of the loaded resin was also studied. 相似文献
95.
A rapid method for calculating the time dependence of activities of individual radionuclides in genetically coupled decay
series has been proposed. The method is based on the mathematical procedure, in which the matrix method is used for calculating
a set of decay equations given in the vector form. The developed method is computerized and uses the modern Scilab software.
This simple method eliminates certain drawbacks of older methods used previously for this purpose and is applicable to even
solve calculations which are not easily treatable with the older methods. Some practical examples of such calculations are
presented. Moreover, the new method is universal and it also enables a more general approach to the problem of the calculation
of decay series in nuclear chemistry.
相似文献
96.
《Analytical letters》2012,45(11):549-561
Abstract The authors studied the possible employment of various compounds containing sulfur as masking agents for divalent and trivalent metals, in the titration of thorium with EDTA. Reagents studied were thioglicolic acid, 3-mercaptopropionic acid, 2-mercaptoethanol, 2,3-dimercaptopropanol, BIS (2-hydroxy ethyl) dithlocarbamate, ethylxantate, thionalid, thiourea and thiosulfate. The ones which proved more efficient were 2,3-dimercaptopropanol and BIS (2-hydroxyethyl) dithiocarbamate. 相似文献
97.
The extraction of thorium(IV) was investigated using two types of W/O microemulsion,one of which was formed by a surface-active saponified extractant sodium bis(2-ethylhexyl) phosphate(NaDEHP) and the other was formed by a mixture of an anionic surfactant sodium bis(2-ethylhexyl) sulfosuccinate(AOT) and an extractant bis(2-ethylhexyl)phosphoric acid(HDEHP) as the cosurfactant.The extraction capacities of the above two systems were higher than that of the HDEHP extraction system.High concentration of NaNO 3 showed no influence on the extraction in the NaDEHP based W/O microemulsion system,whilst reduced the extractability in the AOT-HDEHP W/O microemulsion system.The mechanism in acidic condition was demonstrated by the log-log plot method.The structure of the aggregations and the water content in the organic phase after extraction were measured by dynamic light scattering and Karl Fischer water titration,respectively.It was found that NaDEHP based W/O microemulsion broke up after extraction,while AOT-HDEHP W/O microemulsion was reserved. 相似文献
98.
The thermal expansivity and mean-square thermal vibrational amplitudes were determined as a function of temperature for thorium from first principles total energy calculations using the full potential linearized augmented plane wave (FP-LAPW) method. The coefficient of thermal expansion determined from variation of theoretical potential energy with interatomic separation is ~1.427 × 10?5 K?1 as compared to an experimental value of 1.23 × 10?5 K?1. The mean-square thermal vibrational amplitudes determined as a function of temperature from the theoretically calculated volume-dependent Debye temperature agree well with experimental data derived form neutron diffraction measurements. The melting temperature of thorium, determined theoretically from the mean-square thermal vibrations and the Lindemann rule for melting, is 2234 K, as compared to the reported experimental value of 2021 K. 相似文献
99.
A. Cecal A. Gulea V. Rudic I. Palamaru D. Humelnicu K. Popa 《Isotopes in environmental and health studies》2013,49(3):327-331
Abstract Using different algea types the bioaccumulation of UO2 2+ and Th4+ ions from experimental residual wastes of nuclear facilities was investivated. The retaining degree of these ions on microbiological sorbents decreases as: Scenedesmus quadricauda > Porphyridium cruentum > Spirulina platensis > Calothrix sp.2 > Calothrix sp.1 for UO2 2+ and Porphyridium cruentum > Spirulina platensis > Scenedesmus quadricauda for Th 4+. For the same algae it was observed that the retaining degree is much higher for UO2 2+ than for Th4+, probably due to the different linking degrees of hydrolysed species of these ions on the macromolecular compounds of the living cells through the chemical functional groups. 相似文献
100.
B. M. Moharram N. S. Shakir A. F. Hafez 《Isotopes in environmental and health studies》2013,49(4):199-202
By using 14 MeV neutron flux of 3.5 × 1010 n/cm2 · s, the activities of the activated nuclides in both ferrosilicon alloy (from Kima-Aswan Company) and black sand samples (from the mouth of Damietta, North of Egyptian Delta), were measured. The rate dose of natural gamma-activities arising from Th-232 in the black sand area was calculated. 相似文献