Theoretical studies on the complexation of uranyl with typical carboxylate and amidoximate ligands

Xu, C. B.; Su, Jing; Xu, Xinhua; Li, Jun

doi:10.1007/s11426-013-4994-6

Cited by 20 publications

(13 citation statements)

References 49 publications

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“…Here we demonstrated the application of XANES analysis to explore the uranium local structure in a uranyl-amidoximate (AO) complex solution. AO-based absorbents exhibit superior uranium sequestering ability from seawater, in which the coordination structure of AO with uranyl have key roles (Tian et al, 2012;Vukovic & Hay, 2013;Vukovic et al, 2012;Barber et al, 2012;Xu et al, 2013) in designing highly selective and efficient materials. However, given the limitations of low uranium concentration in seawater and current synthesis technology, very limited information on the detailed local structure of the intrinsic UO 2…”

Section: Applications Of Xanes Analysismentioning

confidence: 99%

Extraction of local coordination structure in a low-concentration uranyl system by XANES

et al. 2016

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Obtaining structural information of uranyl species at an atomic/molecular scale is a critical step to control and predict their physical and chemical properties. To obtain such information, experimental and theoretical L3-edge X-ray absorption near-edge structure (XANES) spectra of uranium were studied systematically for uranyl complexes. It was demonstrated that the bond lengths (R) in the uranyl species and relative energy positions (ΔE) of the XANES were determined as follows: ΔE1 = 168.3/R(U-Oax)(2) - 38.5 (for the axial plane) and ΔE2 = 428.4/R(U-Oeq)(2) - 37.1 (for the equatorial plane). These formulae could be used to directly extract the distances between the uranium absorber and oxygen ligand atoms in the axial and equatorial planes of uranyl ions based on the U L3-edge XANES experimental data. In addition, the relative weights were estimated for each configuration derived from the water molecule and nitrate ligand based on the obtained average equatorial coordination bond lengths in a series of uranyl nitrate complexes with progressively varied nitrate concentrations. Results obtained from XANES analysis were identical to that from extended X-ray absorption fine-structure (EXAFS) analysis. XANES analysis is applicable to ubiquitous uranyl-ligand complexes, such as the uranyl-carbonate complex. Most importantly, the XANES research method could be extended to low-concentration uranyl systems, as indicated by the results of the uranyl-amidoximate complex (∼40 p.p.m. uranium). Quantitative XANES analysis, a reliable and straightforward method, provides a simplified approach applied to the structural chemistry of actinides.

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Section: Applications Of Xanes Analysismentioning

confidence: 99%

Extraction of local coordination structure in a low-concentration uranyl system by XANES

et al. 2016

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“…[39][40][41][42] Again we will use R2 as an example;t he resultsa re shown in Table 1. Here, the bond order refers to the Wiberg bond index in the natural population analysis (NPA), which is widely used in the bond analysis of polymers.…”

Section: Analysis Of the Bonding Propertiesmentioning

confidence: 99%

“…Here, the bond order refers to the Wiberg bond index in the natural population analysis (NPA), which is widely used in the bond analysis of polymers. [39][40][41][42] Again we will use R2 as an example;t he resultsa re shown in Table 1. The bond length of 2a is about 1.60 i nt he reactant and the bond order is 0.93.…”

Section: Analysis Of the Bonding Propertiesmentioning

confidence: 99%

Depolymerization of Free‐Radical Polymers with Spin Migrations

Wang

Dai

et al. 2015

ChemPhysChem

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The mechanism of depolymerization is one of the most essential issues in chemical engineering and materials science. In this work, we investigate the depolymerization reactions of three typical free-radical poly(alpha-methylstyrene) tetramers by using first-principles density functional theory. The calculated results show that these reactions all need to overcome the energy barriers in the range of 0.58 to 0.77 eV, and that breaking the C-C bond at the chain end leads to the dissociation of alpha-methylstyrene monomers from the polymers. Electronic-structure analysis indicates that the reactions occur easily at the CR3 unsaturated end, and that the frontier molecular orbitals that participate in the reactions are mainly localized at the unsaturated ends. Meanwhile, spin population analysis presents the unique net spin-transfer process in free-radical depolymerization reactions. We hope the current findings can contribute to understanding the free-radical depolymerization mechanism and help guide future experiments.

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“…However, there are very few reports with limited insight into uranyl–salophens containing lactam . In the work reported here, a six‐membered ring lactam, in a parallel manner, was introduced into uranyl–salophens, and asymmetric uranyl–salophens containing the six‐membered ring lactam with R / S configuration ( R ‐/ S ‐AUSRLs) were formed, which were then coordinated with N atom in cis −/ trans ‐methylcyclohexylamines ( cis −/ trans ‐MCHAs).…”

Section: Introductionmentioning

confidence: 99%

“…[39][40][41] However, there are very few reports with limited insight into uranyl-salophens containing lactam. [42,43] In the work reported here, a six-membered ring lactam, in a parallel manner, was introduced into uranyl-salophens, and asymmetric uranyl-salophens containing the sixmembered ring lactam with R/S configuration (R-/S-AUSRLs) were formed, which were then coordinated with N atom in cis−/trans-methylcyclohexylamines (cis−/ trans-MCHAs). The coordination selectivity and molecular recognition were explored theoretically, and some significant results were obtained, which could provide insightful information and theoretical guidance for understanding the molecular recognition of R-/S-AUSRLs for cis −/trans-type substituted cyclohexylamine derivatives.…”

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confidence: 99%

Theoretical investigation into the coordination of R‐/S‐asymmetric uranyl–salophens containing six‐membered ring lactam with cis−/trans‐cyclohexylamines

Yang

Kong

et al. 2018

Applied Organom Chemis

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A six‐membered ring lactam derivative was introduced in a parallel manner into uranyl–salophens with R/S configuration (R‐/S‐AUSRLs), which were used as receptors to coordinate with guests of cis−/trans‐methylcyclohexylamines (cis−/trans‐MCHAs). Using density functional theory calculations at the B3LYP/6‐311G** level and RECP, an insight into the coordination complexes of the R‐/S‐AUSRLs with cis−/trans‐MCHAs was obtained. The results showed that the U atoms of receptors could coordinate with the N atoms of four kinds of cis−/trans‐1,2 or − 1,4 guests, but the two kinds of cis−/trans‐1,3 guests could not be converged by the same method in the process of structural optimization due to steric hindrance, and thus the cis−/trans‐1,3 guests could not be coordinated with the R‐/S‐AUSRLs. The mode of coordination of the R‐/S‐AUSRLs with the guests displayed a significant difference. And the change of R‐AUSRL coordination ability to the cis−/trans‐MCHAs was very large, but that of S‐AUSRL was small. Overall, the stability of the R‐series coordination complexes was higher than that of the corresponding S‐series coordination complexes, and the R‐AUSRL receptor had better coordination selectivity and higher molecular recognition to the cis−/trans‐MCHA guests than the S‐AUSRL receptor. However, the coordination ability of S‐AUSRL with the cis−/trans‐MCHAs was stronger than that of R‐AUSRL. It was expected that these results could provide insightful information and theoretical guidance for understanding the molecular recognition of R‐/S‐AUSRLs for cis−/trans‐type cyclohexylamine derivatives.

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Theoretical studies on the complexation of uranyl with typical carboxylate and amidoximate ligands

Cited by 20 publications

References 49 publications

Extraction of local coordination structure in a low-concentration uranyl system by XANES

Extraction of local coordination structure in a low-concentration uranyl system by XANES

Depolymerization of Free‐Radical Polymers with Spin Migrations

Theoretical investigation into the coordination of R‐/S‐asymmetric uranyl–salophens containing six‐membered ring lactam with cis−/trans‐cyclohexylamines

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