Soft donor ligands often provide higher selectivity for actinides(III) over chemically similar lanthanides(III), e.g., in the AmIII–EuIII pair. Frequently, origin of such is associated with an increased covalency actinide–ligand bonding. However, relationship between degree and ion has yet to reach general consensus. Further, it unclear whether enhanced leads a thermodynamic stabilization complex or not. Using relativistic density functional theory, we have addressed these outstanding issues...

Achieving an efficient separation of chemically similar Am3+/Eu3+ pair in high level liquid waste treatment is crucial for managing the long-term nuclear disposal issues. The use sophisticated supramolecules a rigid framework could be next step toward solving long-standing problem. Here, we have investigated possibility separating with cucurbit-[5]-uril (CB[5]), macrocycle from cucurbit-[n]-uril family, using relativistic density functional theory (DFT) based calculations. We explored...

Straight chain amide N,N-dihexyloctanamide (DHOA) has been found to be a promising alternative extractant tri-n-butyl phosphate (TBP) for the reprocessing of irradiated uranium- and thorium-based fuels. Unlike TBP, DHOA displays preferential extraction Pu(IV) over U(VI) at higher acidities (≥3 M HNO3) poor lower acidities. Density functional theory (DFT) based calculations have carried out on structures relative binding energies with molecules. These suggest that differential hardness two...

Recently, Auramine O (AuO) has been projected as a fluorescent fibril sensor, and it claimed that AuO an advantage over the most extensively utilized marker, Thioflavin-T (ThT), owing to presence of additional large red-shifted emission band for AuO, which was observed exclusively in fibrillar media not protein or buffer media. As fibrils are very rich β-sheet structure, sensor should be more specific toward structure so produce contrast between form native form, efficient detection vitro...

An Ir(III) complex catalyzed single and dual reductive amination followed by N-methylation of aldehydes ketones to synthesize N,N-dimethyl as well N-methyl tertiary amines, respectively, utilizing ammonium formate methanol N1 C1 sources is reported. The protocol was efficiently extended a tandem amination/N-methylation/cyclization keto acids/esters leading lactams. A broad substrate scope, synthesis bioactive molecules, also demonstrated. Control experiments, kinetic studies, DFT...

The effect of successive alkylation the Cα atom adjacent to carbonyl group in N,N-dialkyl amides (i.e., di(2-ethylhexyl)acetamide (D2EHAA), di(2-ethylhexyl)propionamide (D2EHPRA), di(2-ethylhexyl)isobutyramide (D2EHIBA), and di(2-ethylhexyl)pivalamide (D2EHPVA)) on extraction behavior hexavalent uranium (U(VI)) tetravalent thorium (Th(IV)) ions has been investigated. These studies show that Th(IV) is significantly suppressed compared U(VI) with increased branching at group. Small angle...

Small-angle neutron scattering (SANS) studies were carried out to compare the aggregation behavior of 1.1 M solutions tributyl phosphate (TBP) and N,N-dihexyl octanamide (DHOA) dissolved in different deuterated diluents, viz., n-dodecane, chloroform, benzene, during extraction Th(IV) from nitric acid medium. The data was treated using Baxter sticky spheres model. third phase formed case DHOA displayed higher tendency compared that TBP. These have demonstrated nature diluents plays an...

2-(4′-Pyridyl)benzimidazole (4PBI) can exist in several states of protonation, having three basic nitrogen atoms. The equilibria involving these states, ground as well excited are found to be affected significantly by cyclodextrins (CDs). formation inclusion complexes this compound with all varieties is observed more favorable at pH 9 than 4, due the predominance neutral form dye 9. binding affinity 4PBI CDs governed two factors: (i) size host and (ii) mode insertion 4PBI. We find that, for...

In the context of mitigation biological effects internal radionuclide contamination and for efficient decorporation, design development chelators lanthanide actinide metal ions has become a central issue. The pioneering work Raymond coworkers (Chem. Rev., 2003, 103, 4207-4282) led to siderophore-related hydroxypyridinonate ligands possible treatment internalized radionuclides. However, structure-function relationship Ln/An bound these ligands, particularly bonding coordination aspects are...

The migration of potentially harmful radionuclides, such as cesium (137Cs) and strontium (90Sr), in soil is governed by the chemical biological reactivity components. Soil organic matter (SOM) that can be modeled through fulvic acid (FA) known to alter mobility radionuclide cations, Cs+ Sr2+. Shedding light on possible interaction mechanisms at atomic level these two ions with FA thus vital explain their transport behavior for design new ligands efficient extraction radionuclides. Here we...

The selective separation of uranyl ions from an aqueous solution is one the most important criteria for sustainable nuclear energy production. We report herein a known, but unexplored extractant, tetraalkyl urea, which shows supreme selectivity uranium in presence interfering thorium and other lanthanide nitric acid medium. structural characterization complex (UO2X2·2L, where X = NO3(-), Cl(-) Br(-)) by IR, NMR single crystal X-ray diffraction provides insight into strong interaction between...

Due to the long half-life of 137Cs (t1/2 ∼ 30 years), selective extraction cesium (Cs) from high level liquid waste is paramount importance in back end nuclear fuel cycle avoid term surveillance radiotoxic waste. As 1,3-di-octyloxycalix[4]arene-crown-6 (CC6) suggested be a promising candidate for Cs extraction, improvement efficiency by CC6 has been investigated through optimization effect dielectric media on process. The effects feed acid (HNO3, HCl, and HClO4) composition diluents ligand...

A relativistic density functional theory (DFT) study is reported which aims to understand the complexation chemistry of An4+ ions (An = Th, U, Np, and Pu) with a potential decorporation agent, 5-LIO(Me-3,2-HOPO). The calculations show that periodic change metal binding free energy has an excellent correlation ionic radii such also leads structural modulation actinide-ligand complexes. calculated parameters agree well available experimental data. Atomic charges derived from quantum atoms in...

Ion channels, such as potassium channels are known to discriminate ions achieve remarkable selective transportation of K(+) over Na(+) through the membrane. The recently reported NaK ion channel, on contrary, seems be an exception, it is observed permeate most group IA alkali metal cations and hence suggested nonselective in nature. However, does that correspond a complete annihilation selectivity inside filter (SF) channel? What origin nonselectivity/selectivity, if any? present...

Designing new and innovative receptors for the selective binding of radionuclides is central to nuclear waste management processes. Recently, a multi-topic ion-pair receptor was reported which binds variety cesium salts. Due large size receptor, quantum chemical calculations on full are restricted, thus mechanisms not well understood at molecular level. We have assessed strengths various salts recently synthesized molecule using density functional theory based calculations. Our predict that...

Rationale Mandelic acid is a complexing agent employed for the liquid chromatographic separation of actinides. However, types species and structural details uranyl‐mandelate complexes are still unknown. Understanding nature these complex would provide better insight into mechanism their in chromatography. Methods Formation different uranyl ion (UO 2 ) with mandelic was studied using electrospray ionization mass spectrometry (ESI‐MS) quadrupole time‐of‐flight analyzer. The nitrate (MA) at...

A plethora of chemical reactions is redox driven processes. The conversion toxic and highly soluble U(VI) complexes to nontoxic insoluble U(IV) form are carried out through proton coupled electron transfer by iron containing cytochromes mineral surfaces such as machinawite. This process takes place the formation U(V) species which unstable immediately undergo disproportionation reaction. Thus, theoretical methods extremely useful understand reduction species. We here have structures...

An unusual intramolecular CH⋯O hydrogen bonding interaction between a sterically bulky amide and uranyl oxygen is found to selectively extract uranyl.

Search for new U(VI) sequestering macrocyclic ligands is an important area of research due to manifold applications. Besides hard- or soft-donor-based ligands, mixed-donor are also gaining popularity in achieving optimized performances. However, how the combination hard-soft-donor centers alters bonding interactions with still not well-understood. Moreover, a consensus yet be reached on nature and role underlying covalent mixed N,O-donor ligands. In this work, using relativistic density...

A phenomenological model has been developed for the mechanism of action phase modifiers as additives that control aggregation phenomena within water-in-oil emulsions. The "Dispersion by Competitive Intermolecular Interaction" (DCI) explicitly considers strength and prevalence different intermolecular interactions influence molecular association amphiphiles, resulting distribution aggregate size, interaggregate phenomena. existing "cosolvent" "cosurfactant" models, which describe these...