Controlling the Reduction of Chelated Uranyl to Stable Tetravalent Uranium Coordination Complexes in Aqueous Solution.
Inorg Chem
; 60(2): 973-981, 2021 Jan 18.
Article
em En
| MEDLINE
| ID: mdl-33356197
ABSTRACT
The solution-state interactions between octadentate hydroxypyridinone (HOPO) and catecholamide (CAM) chelating ligands and uranium were investigated and characterized by UV-visible spectrophotometry and X-ray absorption spectroscopy (XAS), as well as electrochemically via spectroelectrochemistry (SEC) and cyclic voltammetry (CV) measurements. Depending on the selected chelator, we demonstrate the controlled ability to bind and stabilize UIV, generating with 3,4,3-LI(1,2-HOPO), a tetravalent uranium complex that is practically inert toward oxidation or hydrolysis in acidic, aqueous solution. At physiological pH values, we are also able to bind and stabilize UIV to a lesser extent, as evidenced by the mix of UIV and UVI complexes observed via XAS. CV and SEC measurements confirmed that the UIV complex formed with 3,4,3-LI(1,2-HOPO) is redox inert in acidic media, and UVI ions can be reduced, likely proceeding via a two-electron reduction process.
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Base de dados:
MEDLINE
Idioma:
En
Ano de publicação:
2021
Tipo de documento:
Article
País de afiliação:
Estados Unidos