作者机构：
[Wu Si; Nie Chang-Ming] Univ South China, Sch Chem & Chem Engn, Hengyang 421001, Peoples R China.;[Mei Lei; Hu Kong-Qiu; Wu Si; Shi Wei-Qun; Chai Zhi-Fang] Chinese Acad Sci, Inst High Energy Phys, Lab Nucl Energy Chem, Beijing 100049, Peoples R China.;[Chai Zhi-Fang] Chinese Acad Sci, Ningbo Inst Ind Technol, Engn Lab Adv Energy Mat, Ningbo 315201, Peoples R China.
通讯机构：
[Wu Si] U;[Wu Si] C;Univ South China, Sch Chem & Chem Engn, Hengyang 421001, Peoples R China.;Chinese Acad Sci, Inst High Energy Phys, Lab Nucl Energy Chem, Beijing 100049, Peoples R China.
摘要：
In this work, we report a novel octa-nuclear uranyl (U8) motif [(UO2)(8)O-4(mu(3)-OH)(2)(mu(2)-OH)(2)](4+) embedded in a uranyl-oxalate coordination polymer (compound 1) based on a U-shaped linker with extra-long xylylene chains for stabilizing the resulting high-nuclear motif through additional cross-linking connectivity. A comparison with dimeric and monomeric uranyl compounds obtained at different pH value from the same hydrothermal system reveals that, solution pH plays a vital role in formation of this octa-nuclear uranyl motif by promoting hydrolysis of uranyl source. Since high similarity of eight uranium centers in this nearly planar U8 motif here, overlapping and broadening of signals in fluorescence, infra-red (IR) and Raman spectra can be found.
作者机构：
[Wu, Qun-Yan; Kong, Xiang-He; Chai, Zhi-Fang; Wang, Cong-Zhi; Lan, Jian-Hui; Shi, Wei-Qun; Wang, Cui] Chinese Acad Sci, Inst High Energy Phys, Lab Nucl Energy Chem, Beijing 100049, Peoples R China.;[Nie, Chang-Ming; Kong, Xiang-He; Wang, Cui] Univ South China, Sch Chem & Chem Engn, Hengyang 421001, Peoples R China.;[Chai, Zhi-Fang] Chinese Acad Sci, Ningbo Inst Ind Technol, Engn Lab Adv Energy Mat, Ningbo 315201, Zhejiang, Peoples R China.
通讯机构：
[Shi, Wei-Qun] C;Chinese Acad Sci, Inst High Energy Phys, Lab Nucl Energy Chem, Beijing 100049, Peoples R China.
摘要：
Separation of trivalent actinides An(III) from lanthanides Ln(III) is a worldwide challenge owing to their very similar chemical behaviors. It is highly desirable to understand the nature of selectivity for the An(III)/Ln(III) separation with various ligands through theoretical calculations because of their radiotoxicity and experimental difficulties. In this work, we have investigated three dithioamide-based ligands and their extraction behaviors with Am(III) and Eu(III) ions using the scalar-relativistic density functional theory. The results show that the dithioamide-based ligands have stronger electron donating ability than do the corresponding diamide-based ones. All analyses including geometry, Mulliken population, QTAIM (quantum theory of atoms in molecules), and NBO (natural bond orbital) suggest that the Am-S/N bonds possess more covalency compared to the Eu-S/N bonds, and the M-S bonds have more covalent character than the M-N bonds. Thermodynamic results reveal that N-2,N-9-diethyl-N-2,N-9-di-p-tolyl-1,10-phenanthroline-2,9-bis(carbothioamide) (L-2) has a stronger complexing ability with metal ions owing to its rigid structure and that N-6,N-6'-diethyl-N-6,N-6'-di-p-tolyl-[2,2'-bipyridine]-6,6'-bis(carbothioamide) (L-2) shows a higher selectivity for the Am(III)/Eu(III) separation. In addition, these dithioamide-based ligands possess Am(III)/Eu(III) selectivity higher than those of the corresponding diamide-based ones, although the former have weaker complexing ability with metal ions, probably due to the greater covalency of the M-S bonds. This theoretical evaluation provides valuable insights into the nature of the selectivity for the Am(III)/Eu(III) separation and information on designing of efficient An(III)/Ln(III) separation with dithioamide-based ligands.
摘要：
<jats:p>A six‐membered ring lactam derivative was introduced in a parallel manner into uranyl–salophens with <jats:italic>R</jats:italic>/<jats:italic>S</jats:italic> configuration (<jats:italic>R</jats:italic>‐/<jats:italic>S</jats:italic>‐AUSRLs), which were used as receptors to coordinate with guests of <jats:italic>cis</jats:italic>−/<jats:italic>trans</jats:italic>‐methylcyclohexylamines (<jats:italic>cis</jats:italic>−/<jats:italic>trans</jats:italic>‐MCHAs). Using density functional theory calculations at the B3LYP/6‐311G** level and RECP, an insight into the coordination complexes of the <jats:italic>R</jats:italic>‐/<jats:italic>S</jats:italic>‐AUSRLs with <jats:italic>cis</jats:italic>−/<jats:italic>trans</jats:italic>‐MCHAs was obtained. The results showed that the U atoms of receptors could coordinate with the N atoms of four kinds of <jats:italic>cis</jats:italic>−/<jats:italic>trans</jats:italic>‐1,2 or−1,4 guests, but the two kinds of <jats:italic>cis</jats:italic>−/<jats:italic>trans</jats:italic>‐1,3 guests could not be converged by the same method in the process of structural optimization due to steric hindrance, and thus the <jats:italic>cis</jats:italic>−/<jats:italic>trans</jats:italic>‐1,3 guests could not be coordinated with the <jats:italic>R</jats:italic>‐/<jats:italic>S</jats:italic>‐AUSRLs. The mode of coordination of the <jats:italic>R</jats:italic>‐/<jats:italic>S</jats:italic>‐AUSRLs with the guests displayed a significant difference. And the change of <jats:italic>R</jats:italic>‐AUSRL coordination ability to the <jats:italic>cis</jats:italic>−/<jats:italic>trans</jats:italic>‐MCHAs was very large, but that of <jats:italic>S</jats:italic>‐AUSRL was small. Overall, the stability of the <jats:italic>R</jats:italic>‐series coordination complexes was higher than that of the corresponding <jats:italic>S</jats:italic>‐series coordination complexes, and the <jats:italic>R</jats:italic>‐AUSRL receptor had better coordination selectivity and higher molecular recognition to the <jats:italic>cis</jats:italic>−/<jats:italic>trans</jats:italic>‐MCHA guests than the <jats:italic>S</jats:italic>‐AUSRL receptor. However, the coordination ability of <jats:italic>S</jats:italic>‐AUSRL with the <jats:italic>cis</jats:italic>−/<jats:italic>trans</jats:italic>‐MCHAs was stronger than that of <jats:italic>R</jats:italic>‐AUSRL. It was expected that these results could provide insightful information and theoretical guidance for understanding the molecular recognition of <jats:italic>R</jats:italic>‐/<jats:italic>S</jats:italic>‐AUSRLs for <jats:italic>cis</jats:italic>−/<jats:italic>trans</jats:italic>‐type cyclohexylamine derivatives.</jats:p>
期刊：
DEStech Transactions on Computer Science and Engineering,2018年(mso):540-547 ISSN：2475-8841
作者机构：
[Qi-qi CHEN; Chang-ming NIE; Ying-wu LIN; Zhi-lin WU; Li-fu LIAO] School of Chemistry and Chemical Engineering,University of South China
会议地点：
中国广东深圳
摘要：
The insight into antitumor activity of isoflavene-thiosemicarbazone hybrids and their molecular structure characterizations were studied by using density functional theory(DFT) method at the level of
作者机构：
[Wu, Si; Li, Fei-ze; Hu, Kong-qiu; Mei, Lei; An, Shu-wen; Chai, Zhi-fang; Shi, Wei-qun] Chinese Acad Sci, Inst High Energy Phys, Lab Nucl Energy Chem, Beijing 100049, Peoples R China.;[Wu, Si; Nie, Chang-ming] Univ South China, Sch Chem & Chem Engn, Hengyang 421001, Peoples R China.;[Chai, Zhi-fang] Chinese Acad Sci, Ningbo Inst Ind Technol, Engn Lab Nucl Energy Mat, Ningbo 315201, Zhejiang, Peoples R China.
通讯机构：
[Shi, Wei-qun] C;Chinese Acad Sci, Inst High Energy Phys, Lab Nucl Energy Chem, Beijing 100049, Peoples R China.
摘要：
The fluorescence of uranyl originated from electronic transitions (S-11-S-00 and S-10-S-0v, v = 0-4) of the ligand-to-metal charge transfer (LMCT) process is an intrinsic property of many uranyl coordination compounds. However, light-induced regulation on fluorescence features of uranyl hybrid materials through photoactive functional groups is less investigated. In this work, the photoactive vinyl group-containing ligands, (E)-methyl 3-(pyridin-4-yl)acrylate and (E)-methyl 3-(pyridin-3-yl)acrylate, have been used in the construction of uranyl coordination polymers in the presence of 1,10-phenanthroline (phen). Five compounds (UO2)(3)(mu(3)-O)(mu(2)-OH)(2)(L-1)(2)(phen)(2)(1), (UO2)(3)(mu(3)-O)(mu(2)-OH)(3)(L-1)(phen)(2) (2), (UO2)(3)(mu(3)-O)(mu(2)-OH)(3)(L-2)(phen)(2) (3), [(UO2)(2)(mu(2)-OH)(2)(L-2)(2)(phen)(2)].2H(2)O (4), and (UO2)Zn(SO4)(phen)(H2O)(OH)(2)(5) were obtained under hydrothermal conditions. Compounds 14 are polynuclear uranyl structures with abundant pp interactions and hydrogen bonds contributed to the 3D crystal packing of them. As model compounds, 1 and 3 are selected for exploring photoresponsive behaviors. The emission intensities of these two compounds are found to decrease gradually over the exposure time of UV irradiation. X-ray single crystal structural analysis suggests that the fluorescence attenuation can be explained by the slight rotation of pyridinyl groups around the carboncarbon double bond during UV irradiation, which is accompanied by the change of weak interactions, i.e., pp interactions and hydrogen bonds in strength and density. This feature of light-induced fluorescence attenuation may enable these two compounds to act as potential photoresponsive sensor materials.
摘要：
In this paper, we synthesized and characterized a di-tetradentate macrocyclic ligand as a novel resonance fluorescence probe for the determination of uranium. The ligand contains two tetradentate ligand moieties and can chelate two cations to form binuclear complex. We found that when the ligand only chelates a uranyl ion or europium (III) ion, the formed complex can only produce weak resonance fluorescence. When the ligand chelates simultaneously uranyl and europium (III) to form heterobinuclear complex, the formed complex can produce strong resonance fluorescence due to the cation-cation interaction between uranyl and europium (III). Based on this finding, we established a resonance fluorescence chemosensor for the determination of uranium (VI) by utilizing the formation of the heterobinuclear complex. Under optimal conditions, the linear range for the determination of uranium (VI) is 0.008-1.2 nmol mL(-1) with a detection limit of 0.002 nmol mL(-1). The method has been applied to determine uranium (VI) in environmental water samples with the recoveries between 95.7% and 103.6%. (C) 2018 Elsevier B.V. All rights reserved.
