Within the pC(H) range of 2.5 to 4.2, gluconate forms three uranyl complexes UO(2)(GH(4))(+), UO(2)(GH(3))(aq), and UO(2)(GH(3))(GH(4))(-), through the following reactions: (1) UO(2)(2+) + GH(4)(-) = UO(2)(GH(4))(+), (2) UO(2)(2+) + GH(4)(-) = UO(2)(GH(3))(aq) + H(+), and (3) UO(2)(2+) + 2GH(4)(-) = UO(2)(GH(3))(GH(4))(-) + H(+). Complexes were inferred from potentiometric, calorimetric, NMR, and EXAFS studies. Correspondingly, the stability constants and enthalpies were determined to be log beta(1) = 2.2 +/- 0.3 and DeltaH(1) = 7.5 +/- 1.3 kJ mol(-1) for reaction (1), log beta(2) = -(0.38 +/- 0.05) and DeltaH(2) = 15.4 +/- 0.3 kJ mol(-1) for reaction (2), and log beta(3) = 1.3 +/- 0.2 and DeltaH(3) = 14.6 +/- 0.3 kJ mol(-1) for reaction (3), at I = 1.0 M NaClO(4) and t = 25 degrees C. The UO(2)(GH(4))(+) complex forms through the bidentate carboxylate binding to U(VI). In the UO(2)(GH(3))(aq) complex, hydroxyl-deprotonated gluconate (GH(3)(2-)) coordinates to U(VI) through the five-membered ring chelation. For the UO(2)(GH(3))(GH(4))(-) complex, multiple coordination modes are suggested. These results are discussed in the context of trivalent and pentavalent actinide complexation by gluconate.
Download full-text PDF |
Source |
|---|---|
| http://dx.doi.org/10.1021/ic8018925 | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
Circular Polymer Designed by Regulating Entropy: Spiro-Valerolactone-Based Polyesters with High Gas Barriers and Adhesion Strength.
J Am Chem Soc
January 2025
Department of Chemistry, Colorado State University, Fort Collins, Colorado 80523-1872, United States.
Enthalpy is often the focal point when designing monomers for polymer circularity, but much less is explored on how entropy can be exploited to create polymers with synergistic circularity and properties. Here, we design a series of spiro-lactones (SLs) with closed-chain cycloalk(en)yl substituents at the α,α-position of δ-valerolactone (δVL), which, when combined with the parent δVL and -α,α-dialkyl-substituted δVL with open-chain alkyl groups, provide a desired platform for exploring the circular polymer design by focusing on the entropy change of polymerization. These SLs exhibit finely balanced (de)polymerizability that is regulated chiefly by entropy differentiation, allowing both the facile synthesis of polyester PSLs ( up to 1000 kg mol) in a living fashion and selective depolymerization of the PSLs to completely recover monomers under mild conditions (using a recyclable catalyst at 100 °C).
View Article and Find Full Text PDFTuning the lanthanide binding tags for preferential actinide chelation: an all atom molecular dynamics study.
Phys Chem Chem Phys
January 2025
Chemistry Division, Bhabha Atomic Research Centre, Mumbai, 400085, India.
The present study focuses on designing mutant peptides derived from the lanthanide binding tag (LBT) to enhance selectivity for trivalent actinide (An) ions over lanthanide (Ln) metal ions (M). The LBT is a short peptide consisting of only 17 amino acids, and is known for its high affinity towards Ln. LBT was modified by substituting hard-donor ligands like asparagine (ASN or N) and aspartic acid (ASP or D) with softer ligand cysteine (CYS or C) to create four mutant peptides: M-LBT (wild-type), M-N103C, M-D105C, and M-N103C-D105C.
View Article and Find Full Text PDFPd catalysts doped with B/C atoms in the subsurface: the positive effect of interstitial atoms in regulating the selectivity of acetylene catalytic hydrogenation.
Phys Chem Chem Phys
January 2025
The State Key Laboratory of Refractories and Metallurgy, Wuhan University of Science and Technology, Wuhan, 430081, China.
At present, the modification of palladium (Pd) catalysts is an important topic due to its potential to enhance catalytic performance and reduce catalyst costs. In this work, boron (B) and carbon (C) are interstitially doped into the subsurface of Pd to construct PdB and PdC catalysts. The adsorption properties of acetylene and ethylene, the mechanism of acetylene hydrogenation, and ethylene selectivity are studied based on density functional theory (DFT) calculations.
View Article and Find Full Text PDFStructural Control of Photoconductivity in a Flexible Titanium-Organic Framework.
Adv Mater
January 2025
Instituto de Ciencia Molecular (ICMol), Universitat de València, Catedrático José Beltrán-2, Paterna, 46980, Spain.
The soft nature of Metal-Organic Frameworks (MOFs) sets them apart from other non-synthetic porous materials. Their flexibility allows the framework components to rearrange in response to environmental changes, leading to different states and properties. The work extends this concept to titanium frameworks, demonstrating control over charge transport in porous molecular crystals.
View Article and Find Full Text PDFSynergizing Monte Carlo simulations and experimental insights for efficient cationic dye removal using natural fluorapatite.
J Mol Model
January 2025
Processes, Materials and Environment Laboratory (LPME), Faculty of Sciences and Technology of Fez, Sidi Mohamed Ben Abdellah University, B.P. 2202, Fez, Morocco.
Context: Natural fluorapatite (FAP) has been investigated as an adsorbent for the removal of dyes such as methylene blue (MB) and crystal violet (CV) from aqueous solutions. Effective dye removal is crucial for water treatment, particularly for industrial wastewater containing toxic dyes. FAP, a naturally abundant material, was characterized using XRD, FTIR, and SEM analysis.
View Article and Find Full Text PDFWant AI Summaries of new PubMed Abstracts delivered to your In-box?
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!