A series of novel hexadentate enterobactin analogues, which contain three catechol chelating moieties attached to different molecular scaffolds with flexible alkyl chain lengths, were prepared. The solution thermodynamic stabilities of the complexes with uranyl, ferric(III), and zinc(II) ions were then investigated. The hexadentate ligands demonstrate effective binding ability to uranyl ion, an...

This study investigated the partitioning of uranyl within a quaternary system made up of uranyl, citrate, goethite, and the bacterium Pseudomonas fluorescens. In the absence of cells, uranyl was sorbed to goethite as a complex involving surface groups and/or citrate. Measurements of the evolution of CO2 indicated that the addition of bacterial cells lead to the gradual biodegradation of citrate...

The family of cage clusters built by uranyl ions bridged through bidentate peroxide groups has been expanded by incorporation of 1-hydroxyethane-1,1-diphosphonic (etidronic) acid ligands. Six cage clusters containing from 16 to 64 uranyl ions, as well as from eight to 32 etidronic acid ligands have been synthesized and characterized. Incorporation of etidronic acid ligands introduces both new c...

Density functional theory calculations were performed on uranyl complexed with nitrate and monoamide ligands (L) [UO(2)(NO(3))(2)·2L]. The obtained results show that the complex stability is mainly governed by two factors: (i) the maximization of the polarizability of the coordinating ligand and (ii) the minimization of the steric hindrance effects. Furthermore, the electrostatic interaction be...

Seven water-soluble, tetradentate bis(3-hydroxy-N-methyl-pyridin-2-one) (bis-Me-3,2-HOPO) ligands were synthesized that vary only in linker geometry and rigidity. Solution-phase thermodynamic measurements were conducted between pH 1.6 and pH 9.0 to determine the effects of these variations on proton and uranyl cation affinity. Proton affinity decreases by introduction of the solubilizing trieth...

Uranyl complexes of rigid aromatic carboxylates were synthesized and their solid-state structures characterized by X-ray crystallography. The new ligands create cavities lined with endohedral functions to encapsulate the uranyl ion.

The development of actinide decorporation agents with high complexation affinity, tissue specificity, and low biological toxicity is vital importance for the sustained healthy nuclear energy. After accidental intake, sequestration by chelation therapy to reduce acute damage considered as most effective method. In this work, a series bis- tetra-phosphonated pyridine ligands have been designed, s...

Complexation thermodynamics of UO22+ and a series N,N,N’,N’-tetraalkyl diglycolamide (TRDGA) ligands having alkyl chains –CH3 to –C6H13 were investigated in an ionic liquid (IL). The complexation constant for UO22+/DGA complex increased linearly with increasing chain length DGA from tetramethyl (logβ1 = 4.52, logβ2 8.01) tetrahexyl 5.62, 10.3). There two types species recorded the calorimetric ...

Uranyl ion complexes with long-chain, saturated or unsaturated aliphatic dicarboxylate ligands illustrate how solvo-hydrothermal synthetic conditions sometimes result in the formation of species different from those hoped for.