A5018827996- Radioactive element chemistry and processing
- Advanced Chemical Physics Studies
- Lanthanide and Transition Metal Complexes
- Radioactive contamination and transfer
- Catalysis and Oxidation Reactions
- Organometallic Complex Synthesis and Catalysis
- Nuclear Materials and Properties
- Magnetism in coordination complexes
- History and advancements in chemistry
- Pesticide and Herbicide Environmental Studies
- Photochemistry and Electron Transfer Studies
- Advanced NMR Techniques and Applications
- Spectroscopy and Quantum Chemical Studies
- Crystallography and molecular interactions
- Nuclear reactor physics and engineering
- Nuclear materials and radiation effects
- Energetic Materials and Combustion
- Chemical Thermodynamics and Molecular Structure
- Drug Solubulity and Delivery Systems
- Genetic Neurodegenerative Diseases
- Amyotrophic Lateral Sclerosis Research
- Cyclopropane Reaction Mechanisms
- Analytical Chemistry and Chromatography
- Metal-Catalyzed Oxygenation Mechanisms
- Quantum, superfluid, helium dynamics
Wallingford Public Library
2018-2020
Stevenson University
2015
Wayne State University
2005-2011
Lawrence Berkeley National Laboratory
2010
University of Utah
2009-2010
University of California, Berkeley
2010
Kyoto University
2010
University of Wisconsin–Eau Claire
2007
The Ohio State University
2002-2006
Los Alamos National Laboratory
2005
Recent advances in computational methods have made it possible to calculate the wave functions for a wide variety of simple actinide complexes. Equally important is ability analyze information contained therein and produce chemically meaningful understanding electronic structure. Yet performance most common function analyses calculation atomic charge bond order has not been thoroughly investigated systems. This particularly relevant because even transition metal complexes known be fraught...
The coordination and bonding of equatorial hydroxide, carbonyl, cyanide (CN-), isocyanide (NC-) ligands with uranyl dication, [UO2]2+, has been studied using density functional theory relativistic effective core potentials. Good agreement is seen between experimental calculated geometries [UO2(OH)4]2-. Newly predicted ground-state structures [UO2(OH)5]3-, [UO2(CO)4]2+, [UO2(CO)5]2+, [UO2(CN)4]2-, [UO2(CN)5]3-, [UO2(NC)4]2-, [UO2(NC)5]3- are reported. Four-coordinate complexes the gas-phase...
The quinquedentate macrocyclic ligand cyclo-6,6'-[1,9-(2,5,8-trithianonane)]-2,2'-bipyridine ([15]aneS3bpy = L), containing two pyridyl nitrogens and three thiaether sulfurs as donor atoms, has been synthesized complexed with copper. CuII/IL redox potential, the stabilities of oxidized reduced complex, oxidation reduction electron-transfer kinetics complex reacting a series six counter reagents have studied in acetonitrile at 25 °C, μ 0.10 M (NaClO4). Marcus cross relationship applied to...
A new method for constructing empirical valence bond potential energy surfaces reactions is presented. Building on the generalized Gaussian approach of Chang-Miller, V12(2)(q) represented by a times polynomial at transition state and to handle any number data points surface. The applied two model HCN isomerization reaction. applications demonstrate that present overcomes divergence problems encountered in some other approaches. use Cartesian versus internal or redundant coordinates discussed.
The rates of intramolecular proton transfer are calculated on a full-dimensional reactive electronic potential energy surface that incorporates high-level ab initio calculations along the reaction path and by using classical transition state theory, path-integral quantum instanton approach. specific example problem studied is malonaldehyde. Estimates kinetic isotope effect latter two methods found to be in reasonable agreement with each other. Improvements extensions this practical, yet...
Intracellular protein aggregation is the hallmark of several neurodegenerative diseases. Aggregates formed by polyglutamine (polyQ)-expanded proteins, such as Huntingtin, adopt amyloid-like structures that are resistant to denaturation. We used a novel purification strategy isolate aggregates human Huntingtin N-terminal fragments with expanded polyQ tracts from both yeast and mammalian (PC-12) cells. Using mass spectrometry we identified species trapped within these aggregates. found...
Complexes of the form An(2)(C(8)H(8))(2) (An = Th, Pa, U, and Np) were investigated using density functional theory with scalar-relativistic effective core potentials. For uranium, a coaxial isomer D(8h) symmetry is found to be more stable than C(s) in which dimetal unit perpendicular C(8) ring axis. Similar structures are predicted for Pa(2)(C(8)H(8))(2) Np(2)(C(8)H(8))(2), while Th(2)(C(8)H(8))(2), C(8)H(8) rings tilt away from An-An Going Th(2)(C(8)H(8))(2) bond length decreases 2.81 A...
The experimental and computational results for the tautomerization reaction of 2-pyridone are reviewed. G3, G4, CBS-APNO, W1 model chemistries used to generate state-of-the-art energetics with without catalytic water molecules in both gas aqueous phases. Reactive, electronic potential energy surface surfaces use molecular dynamics simulations were generated these reactions following a recently improved empirical valence bond formulation. form mechanics potentials needed satisfactory fit is...
Density functional theory is employed to investigate uranyl dihydroxide, UO2(OH)2, isomerization reaction energy barriers, including those occurring via proton shuttles. The ground-state structure of a dihydroxide complex containing moiety with near 90 degrees O=U=O bond angle reported for the first time. Furthermore, we predict vibrational spectra these compounds. Scalar-relativistic effects uranium are treated by employing relativistic effective core potential.
Determining stability constants of uranyl complexes with the principal functional groups in siderophores and identifying series is great importance to predict which siderophore classes preferentially bind UVI and, hence, impact uranium speciation environment. It also helps develop resins for scavenging from aqueous solutions. Here, we apply a recently developed computational approach calculate log β values set geochemically relevant organometallic using Density Functional Theory (DFT). We...
Uranium (UVI) interacts with organic ligands, subsequently controlling its aqueous chemistry. It is therefore imperative to assess the binding ability of natural molecules. We evidence that density functional theory (DFT) can be used as a practical protocol for predicting stability UVI ligand complexes, allowing development relative series complexes limited experimental data. Solvation methods and DFT settings were benchmarked suggest suitable off-the-shelf solution. The results indicate...
Empirical valence bond (EVB) surfaces have been constructed for 2-pyridone-2-hydroxypyridine proton transfer and the Claisen rearrangement of allyl vinyl ether at MP2/6-311 + G(d,p) level theory. A distributed Gaussian approach is used to approximate interaction matrix elements. Parameters Gaussians are determined by fitting energy, gradient Hessian data obtained from ab initio electronic structure calculations one nine points along reaction path. An efficient DIIS (direct inversion...
Abstract For see ChemInform in Full Text.
Abstract For see ChemInform in Full Text.
In alkaline and saline solutions, uranium VI (U ) forms uranyl salts, limiting its mobility in leachates released from nuclear waste repositories into groundwater. However, recent experimental computational work suggested that natural organic molecules widely present groundwater such as siderophores could potentially prevent solid precipitation because of the formation stable UVI-siderophore complexes. It is important we assess impact on aqueous U chemistry they mobilise contaminated land...
<p>In alkaline and saline solutions, uranium VI (U<sup>VI</sup>)<sup> </sup>forms uranyl salts, limiting its mobility in leachates released from nuclear waste repositories into groundwater. However, recent experimental computational work suggested that natural organic molecules widely present groundwater such as siderophores could potentially prevent solid precipitation because of the formation stable UVI-siderophore complexes. It is important we assess impact...