A5043218823- Radioactive element chemistry and processing
- Crystallization and Solubility Studies
- X-ray Diffraction in Crystallography
- Chemical Synthesis and Characterization
- Crystallography and molecular interactions
- Extraction and Separation Processes
- Lanthanide and Transition Metal Complexes
- Nuclear Materials and Properties
- Supramolecular Chemistry and Complexes
- Analytical chemistry methods development
- Molecular Sensors and Ion Detection
- Radioactive contamination and transfer
- Nuclear reactor physics and engineering
- Electrochemical Analysis and Applications
- Analytical Chemistry and Sensors
- Analytical Chemistry and Chromatography
- Spectroscopy and Chemometric Analyses
- Nuclear materials and radiation effects
- Water Quality Monitoring and Analysis
- Graphite, nuclear technology, radiation studies
- Nuclear and radioactivity studies
- Chemical and Physical Properties in Aqueous Solutions
- Advancements in Battery Materials
- Ionic liquids properties and applications
- Nuclear Physics and Applications
Oak Ridge National Laboratory
2014-2025
University of Oregon
2024
Michigan State University
2024
Government of the United States of America
2022
National Technical Information Service
2008-2021
Office of Scientific and Technical Information
2008-2021
Oak Ridge Associated Universities
2014-2019
Materials Processing (United States)
2015-2016
NOAA Chemical Sciences Laboratory
2013
Separation Systems (United States)
2011
Ditopic cation–anion binding is revealed by solid-state studies of the anion-recognition behavior calix[4]pyrrole unit. Anion causes an electron-rich conelike cavity to be formed that can then bind large polarizable cations. Furthermore, complexation with cesium carbonate results in dimerization, which a single anion bridges two calix[4]pyrroles (see crystal structure Cs2CO3 complex). Supporting information for this article available on WWW under...
An ion-pair receptor, the calix[4]pyrrole-calix[4]arene pseudodimer 2, bearing a strong anion-recognition site but not weak cation-recognition site, has been synthesized and characterized by standard spectroscopic means via single-crystal X-ray diffraction analysis. In 10% CD3OD in CDCl3 (v/v), this new receptor binds neither Cs+ cation nor F− anion when exposed to these species presence of other counterions; however, it forms stable 1:1 solvent-separated CsF complex two ions concert with...
Solvent-extraction studies provide confirming evidence that meso-octamethylcalix[4]pyrrole acts as an ion-pair receptor for cesium chloride and bromide in nitrobenzene solution. The stoichiometry of the interaction under extraction conditions from water to was determined plots distribution ratios vs salt concentration, indicating formation ion-paired 1:1:1 cesium:calix[4]pyrrole:halide complex. results were modeled evaluate equilibria inherent solvent-extraction system, with either or...
In this work, we show that the use of a high boiling point ether solvent (tetraglyme) promotes formation Li2O2 in lithium-air cell. However, another major constituent discharge product Li-air cell contains halides from lithium salts and C-O tetraglyme used as solvent. This information is critical to development electrolytes, which are stable promote desired products.
The rare earth elements (REEs) such as neodymium, praseodymium, and dysprosium were successfully recovered from commercial NdFeB magnets industrial scrap via membrane assisted solvent extraction (MSX). A hollow fiber system was evaluated to extract REEs in a single step with the feed strip solutions circulating continuously through MSX system. effects of several experimental variables on REE flow rate, concentration solution, configuration, composition acids investigated multimembrane module...
The subtle energetic differences underpinning adjacent lanthanide discrimination are explored with diglycolamide ligands. Our approach converges liquid-liquid extraction experiments solution-phase X-ray absorption spectroscopy (XAS) and density functional theory (DFT) simulations, spanning the series. homoleptic [(DGA)3Ln]3+ complex was confirmed in organic extractive solution by XAS, this modeled using DFT. An interplay between steric strain coordination energies apparently gives rise to a...
Abstract Lanthanide rare-earth metals are ubiquitous in modern technologies 1–5 , but we know little about chemistry of the 61st element, promethium (Pm) 6 a lanthanide that is highly radioactive and inaccessible. Despite its importance 7,8 Pm has been conspicuously absent from experimental studies lanthanides, impeding our full comprehension so-called contraction phenomenon: fundamental aspect periodic table quoted general textbooks. Here demonstrate stable chelation 147 radionuclide...
ABSTRACT A robust solvent suitable for extracting cesium from alkaline nitrate media like that of the high-level liquid waste stored at U.S. Department Energy Savannah River Site has been developed. The is composed extractant calix[4]arene-bis-(tert-octylbenzo-crown-6) (“BOBCalixC6”) 0.01 M, modifier l-(2,2,3,3-tetrafluoropropoxy)-3-(4-sec-butylphenoxy)-2-propanol (“Cs-7SBT”) 0.50 trioctylamine (“TOA”) 0.001 and aliphatic diluent Isopar® L. holds up exceptionally well under various stresses,...
Ion pair receptor 3 bearing an anion binding site and multiple cation sites has been synthesized shown to function in a novel binding-release cycle that does not necessarily require displacement effect release. The forms stable complexes with the test cesium salts, CsCl CsNO(3), solution (10% methanol-d(4) chloroform-d) as inferred from (1)H NMR spectroscopic analyses. addition of KClO(4) these salt leads type metathesis which "exchanged" cations occupy different sites. Specifically, K(+)...
Outer-sphere ion clusters are inferred in many important natural and technological processes, but their mechanisms of assembly solution structures difficult to define. Here, we characterize trefoil-shaped outer-sphere lanthanide chloride nitrate hydrocarbon solutions formed during liquid-liquid extraction with diglycolamide ligands. These assembled through steric electrostatic forces, where the anions reside equidistant "clefts" between coordinating ligands positions that satisfy both...
The rare earth elements (REEs) play a vital role in the development of green energy and high-tech industries. In order to meet fast-growing demand ensure sufficient supply REEs, it is essential develop an efficient REE recovery process from post-consumer REE-containing products. this research effort, we have developed supported liquid membrane system utilizing polymeric hollow fiber modules extract REEs neodymium-based magnets with neutral extractants such as tetraoctyl digylcol amide...
To advance the chelation chemistry of elusive radium ion for targeted radionuclide therapy applications, we report its complexation thermodynamics with macrocyclic chelators macropa and DOTA.
Improving actinide separations is key to reducing barriers medical and industrial isotope production addressing the challenges associated with reprocessing of spent nuclear fuel. Here, we report first example a supramolecular anion recognition process that can achieve this goal. We have designed preorganized triamidoarene receptor induces quantitative precipitation early actinides Th(IV), Np(IV), Pu(IV) from industrially relevant conditions through formation self-assembled hydrogen-bonded...
Conformationally rigidified tetraCMPO derivatives have been prepared from calix[4]arene bis(crown ether) 4a in which adjacent oxygens are bridged at the narrow rim by two diethylene glycol links. Acylation of tetraamine 4c with CMPO-active ester 5b gave tetraphosphine oxide 6a, while tetraphosphinate 6b and tetraphosphonate 6c were obtained Arbuzov reaction tetrabromoacetamido derivative 7 PhP(OEt)2 or P(OEt)3. The extraction ability these CMPO was checked for selected lanthanides actinides...
Syntheses for a set of new ligands containing one or two carbamoylmethylphosphine oxide (CMPO) fragments appended to pyridine and N-oxide platforms are described. Molecular mechanics analyses gas phase lanthanide-ligand interactions the N-oxides indicate that trifunctional NOPOCO molecules, 2-{[Ph2P(O)][C(O)NEt2]C(H)}C5H4NO (7) 2-{[Ph2P(O)][C(O)NEt2]CHCH2}C5H4NO (8), pentafunctional NOPOP'O'COC'O' 2,6-{[Ph2P(O)][C(O)NEt2]C(H)}2C5H3NO (9) 2,6-{[Ph2P(O)][C(O)NEt2]CHCH2}2C5H3NO (10), should be...
The Plutonium-238 Supply Program at Oak Ridge National Laboratory has developed the capability to inform process decisions during full-scale 238Pu anion exchange column runs using multivariate chemometrics and visible-near infrared (Vis-NIR) absorption spectroscopy. Multivariate analytical methods provided a suitable option for real-time analysis of complex neptunium (Np) plutonium (Pu) spectra. Thousands spectra from multiple production campaigns were analyzed by principal component...
Abstract A series of novel alkylphenoxy fluorinated alcohols were prepared and investigated for their effectiveness as modifiers in solvents containing calix[4]arene‐bis‐(tert‐octylbenzo)‐crown‐6 the extraction cesium from alkaline nitrate media. The structure portion modifier influences chemical stability, a that contained terminal 1,1,2,2‐tetrafluoroethoxy group was found to decompose following long‐term exposure warm solutions. However, replacement tetrafluoroethoxy with...
Calix[4]arenes substituted by acetamidophosphine oxide groups at their wider (upper) rim not only exhibit excellent extraction efficiency towards trivalent cations but also show pronounced selectivity for the light lanthanides and actinides in from highly saline or acidic media.
Ditop gebundene Kationen und Anionen enthüllten Festkörperstudien zur Anionenerkennung durch die Calix[4]pyrrol-Einheit. Durch Bindung eines Anions bildet sich ein elektronenreicher kegelförmiger Hohlraum, der dann große polarisierbare aufnehmen kann. Die Komplexierung von Calix[4]pyrrol mit Caesiumcarbonat bewirkt eine Dimerisierung, wobei einzelnes Anion zwei Calix[4]pyrrole verbrückt (siehe Struktur des Cs2CO3-Komplexes).
Abstract We previously published a model for cesium extraction from acidic media by the protonated form of hexachlorinated derivative chloro‐protected cobalt bis(dicarbollide), HCCD, dissolved in trifluoromethylphenyl sulfone, FS‐13. The indicated that Cs proceeds through series ion‐paired and/or dissociated equilibria. Additional distribution ratio data has been obtained and refined simplified. It is demonstrated equilibrium exclusively involving exchange proton formation CsCCD models very...
An alkaline-side solvent extraction process was developed for cesium removal from Savannah River Site (SRS) tank waste. The invented at Oak Ridge National Laboratory and tested Argonne using singlestage multistage tests in a laboratory-scale centrifugal contactor. dispersion number, hydraulic performance, stage efficiency, general operability of the flowsheet were determined. Based on these tests, further development work done. final formulation appears to be an excellent candidate removing SRS
Implementing remote, real-time spectroscopic monitoring of radiochemical processing streams in hot cell environments requires efficiency and simplicity. The success optical spectroscopy for the quantification species chemical systems highly depends on representative training sets suitable validation sets. Selecting a set (i.e., calibration standards) to build multivariate regression models is both time- resource-consuming using standard one-factor-at-a-time approaches. This study describes...