A5058363505- X-ray Diffraction in Crystallography
- Crystallization and Solubility Studies
- Radioactive element chemistry and processing
- Lanthanide and Transition Metal Complexes
- Organometallic Complex Synthesis and Catalysis
- Magnetism in coordination complexes
- Inorganic Chemistry and Materials
- Coordination Chemistry and Organometallics
- Metal-Organic Frameworks: Synthesis and Applications
- Chemical Synthesis and Characterization
- Organometallic Compounds Synthesis and Characterization
- Metal complexes synthesis and properties
- Protein Kinase Regulation and GTPase Signaling
- Organic and Molecular Conductors Research
- Analytical chemistry methods development
- Nuclear Materials and Properties
- Crystal structures of chemical compounds
- Rare-earth and actinide compounds
- Enzyme Structure and Function
- Synthesis and characterization of novel inorganic/organometallic compounds
- Extraction and Separation Processes
- Crystallography and molecular interactions
- Cellular transport and secretion
Los Alamos National Laboratory
2023-2025
Florida State University
2020-2023
Government of the United States of America
2023
Miami University
2017
K-Ras, a molecular switch that regulates cell growth, apoptosis and metabolism, is activated when it undergoes conformation change upon binding GTP deactivated following the hydrolysis of to GDP. Hydrolysis in water accelerated by coordination where adopts high-energy approaching transition state. The G12A mutation reduces intrinsic K-Ras an unexplained mechanism. Here, crystal structures complex with GDP, GTP, GTPγS GppNHp, Q61A are reported. In K-Ras-GTP complex, I region significant...
A series of complexes the trivalent actinides Np(III) through Cf(III) (excluding Bk(III)) with maleonitrile-1,2-dithiolate (mnt2–) is synthesized along their lanthanide counterparts (La(III) – Nd(III), Sm(III) Gd(III), Dy(III)), in order to characterize nature chemical bonds these metal ions and a polarizable non-innocent, sulfur-donor ligand. The metal-sulfur trend shorter than measured for lanthanides equivalent ionic radii; however, particularly large deviations are observed neptunium...
<title>Abstract</title> A series of complexes the trivalent actinides Np(III) through Cf(III) (excluding Bk(III)) with maleonitrile-1,2-dithiolate (mnt<sup>2–</sup>) is synthesized along their lanthanide counterparts (La(III) – Nd(III), Sm(III) Gd(III), Dy(III)), in order to characterize nature chemical bonds these metal ions and a polarizable non-innocent, sulfur-donor ligand. The metal-sulfur trend shorter than measured for lanthanides equivalent ionic radii; however, particularly large...
Cyclic voltammetry, UV-vis, and X-ray absorption spectroscopy were used to demonstrate that aqueous plutonium coordination chemistry electron transfer reactivity can be controlled by judicious manipulation of hydrochloric acid concentrations.
Structural and electronic characterization of (Cp'3Cm)2(μ-4,4'-bpy) (Cp' = trimethylsilylcyclopentadienyl, 4,4'-bpy 4,4'-bipyridine) is reported provides a rare example curium-carbon bonding. Cp'3Cm displays unexpectedly low energy emission that quenched upon coordination by 4,4'-bipyridine. Electronic structure calculations on rule out significant differences in the emissive state, rendering 4,4'-bipyridine as primary quenching agent. Comparisons with its samarium gadolinium analogues...
Variations in bonding between trivalent lanthanides and actinides is critical for reprocessing spent nuclear fuel. The ability to tune the coordination environment these systems a key factor identifying solution separating actinides. Coordination of 4,4'-bipyridine (4,4'-bpy) trimethylsilylcyclopentadienide (Cp') americium introduces unexpectedly ionic Am-N character unique spectroscopic properties. Here we report structural characterization (Cp'3Am)2(μ - 4,4'-bpy) its lanthanide analogue,...
Dinuclear, organometallic, transuranium compounds, (Cp'3M)2(μ-4,4'-bpy) (Cp'- = trimethylsilylcyclopentadienide, 4,4'-bpy 4,4'-bipyridine, M Ce, Np, Pu), reported herein provide a rare opportunity to probe the nature of actinide-carbon bonding. Significant splitting f-f transitions results from unusual coordination environment in these complexes and leads electronic properties that are currently restricted organoactinide systems. Structural spectroscopic characterization solid state solution...
The aqueous reaction of mellitic acid (H6mell) with 242PuBr3·nH2O forms two plutonium mellitates, 242Pu2(mell)(H2O)9·H2O (Pu-1α) and 242Pu2(mell)(H2O)8·2H2O (Pu-1β). These compounds are compared to the isomorphous lanthanide mellitates similar ionic radii via bond length analysis. Both form three-dimensional metal–organic frameworks, Pu-1α having unique metal centers Pu-1β one. All exhibit nine-coordinate geometries. Our results show metal–oxygen lengths for significantly shorter than those...
Two neptunium(III) mellitates, 237Np2(mell)(H2O)9·1.5H2O (Np-1α) and 237Np2(mell)(H2O)8·2H2O (Np-1β), have been synthesized from 237NpCl4(dme)2 by reduction with KC8 subsequent reaction an aqueous solution of mellitic acid (H6mell). Characterization single-crystal X-ray crystallography UV-vis-NIR spectroscopy confirms that the neptunium is in its +3 oxidation state both polymorphs are isostructural to previously reported plutonium mellitates. Of two morphologies, Np-1α indefinitely stable...
Pyrithione exhibits size-selective dimerization across the f-block. Experimental and computational analysis shows Am complex contains greater covalency compared to Nd analog.
Here we report the synthesis and structural characterization as well solid- solution-phase studies of Cp′3Am (Cp′– = trimethylsilylcyclopentadienide). The addition KCp′ to AmBr3(DME)2 (DME dimethoxyethane) yields organoamericium complex Cp′3Am, serving a synthetic precursor in field organoactinide synthesis. Significant splitting fingerprint f–f transitions characteristic Am3+ ion is observed. In addition, bonding properties differentiating from few known examples organometallic americium...
The pursuit of a trivalent plutonium halide phosphine oxide compound, e.g., "PuBr3(OPR)3," instead led to the isolation tetravalent trans-PuIVBr4(OPCy3)2, PuBr/Cy, compound by spontaneous oxidation PuIII. donating nature oxides has allowed and characterization PuBr/Cy crystallographic, multinuclear NMR, solid state, solution phase UV-vis-NIR spectroscopic techniques. presence putative plutonyl(VI) complex formulated as "trans-PuVIO2Br2(OPCy3)2" was also observed spectroscopically tentatively...
Structural and electronic characterization of (Cp'3Cm)2(4,4'-bpy) (Cp' = trimethylsilylcyclopentadienyl, 4,4'-bpy 4,4'-bipyridine) is reported provides a rare example curium-carbon bonding. Cp'3Cm displays unexpectedly low energy emission that quenched upon coordination by 4,4'-bipyridine. Electronic structure calculations on rule out significant differences in the emissive state, rendering 4,4'-bipyridine as primary quenching agent. Comparisons with its samarium gadolinium analogues reveal...
Abstract Structural and electronic characterization of (Cp′ 3 Cm) 2 ( µ − 4,4′−bpy) = trimethylsilylcyclopentadienyl, 4,4′−bpy 4,4′−bipyridine) is reported provides a rare example curium carbon bonding. Cp′ Cm displays unexpectedly low energy emission that quenched upon coordination by 4,4′−bipyridine. Electronic structure calculations on rule out significant differences in the emissive state, rendering 4,4′−bipyridine as primary quenching agent. Comparisons with its samarium gadolinium...
Improving f-element separations is important for actinide(III) (An3+) and lanthanide(III) (Ln3+) based technologies. Unfortunately, An3+ Ln3+ ions are difficult to separate from one another because they have similar chemical characteristics. One successful separation method utilizes anion exchange chromatography. This approach exploits differences in Lewis acidities their varying abilities attract anionic complexing agents, like oxalates (C2O42–) diglycolates (ODA2–). The resulting...