Related Experiment Video
Updated: Jun 3, 2026
10:51
The Synthesis, Characterization and Reactivity of a Series of Ruthenium N-triphosPh Complexes
Published on: April 10, 2015
Uranium dioxide in ionic liquid with a tri-n-butylphosphate-HNO3 complex--dissolution and coordination environment
Chien M Wai1, Yu-Jung Liao, Weisheng Liao
1Department of Chemistry, University of Idaho, Moscow, Idaho 83844, USA. cwai@uidaho.edu
Dalton Transactions (Cambridge, England : 2003)
|March 30, 2011
Summary
Uranium dioxide dissolves in ionic liquid using tri-n-butylphosphate-nitric acid. This process efficiently transfers uranyl species to supercritical carbon dioxide without an aqueous phase, aiding in separation.
Area of Science:
- Inorganic Chemistry
- Separation Science
- Materials Science
Background:
- Uranium dioxide dissolution is crucial for nuclear fuel reprocessing and waste management.
- Conventional methods often involve harsh conditions or aqueous phases, posing environmental challenges.
Purpose of the Study:
- To investigate the direct dissolution of uranium dioxide in an ionic liquid at room temperature.
- To explore the transfer of dissolved uranyl species to a supercritical fluid.
- To characterize the extracted uranyl species and the separation mechanism.
Main Methods:
- Dissolution of uranium dioxide in an imidazolium-based ionic liquid with a tri-n-butylphosphate-nitric acid complex.
- Kinetic analysis of the dissolution process.
- Raman spectroscopy to determine uranyl ion coordination.
- Supercritical fluid extraction using carbon dioxide.
- UV-Vis absorption spectroscopy for species characterization.
Main Results:
- Uranium dioxide dissolved readily in the ionic liquid at room temperature, following pseudo first-order kinetics.
- Raman spectroscopy confirmed a 1:2 molar ratio of uranyl ions to tri-n-butylphosphate (TBP).
- Uranyl species were effectively extracted into supercritical carbon dioxide without forming an aqueous phase.
- Extracted species in sc-CO(2) likely form a UO(2)(TBP)(2)(NO(3))(2)·HNO(3) adduct, which separates into dodecane upon pressure reduction.
Conclusions:
- Direct dissolution of uranium dioxide in ionic liquids offers a novel, potentially greener approach.
- Supercritical fluid extraction provides an effective, aqueous-free method for separating uranyl species.
- The developed method shows promise for advanced nuclear fuel cycle applications.
Related Concept Videos
02:54Coordination Compounds and Nomenclature
In most main group element compounds, the valence electrons of the isolated atoms combine to form chemical bonds that satisfy the octet rule. For instance, the four valence electrons of carbon overlap with electrons from four hydrogen atoms to form CH4. The one valence electron leaves sodium and adds to the seven valence electrons of chlorine to form the ionic formula unit NaCl (Figure 1a). Transition metals do not normally bond in this fashion. They primarily form coordinate covalent bonds, a...
02:42Valence Bond Theory
Coordination compounds and complexes exhibit different colors, geometries, and magnetic behavior, depending on the metal atom/ion and ligands from which they are composed. In an attempt to explain the bonding and structure of coordination complexes, Linus Pauling proposed the valence bond theory, or VBT, using the concepts of hybridization and the overlapping of the atomic orbitals. According to VBT, the central metal atom or ion (Lewis acid) hybridizes to provide empty orbitals of suitable...
01:25Microbial Bioremediation of Uranium
Microorganisms play a critical role in the transformation and immobilization of uranium in contaminated environments through four main pathways: bioreduction, biosorption, bioaccumulation, and biomineralization. These mechanisms reduce uranium’s toxicity and prevent its migration through groundwater systems, offering sustainable approaches for in situ bioremediation.Bioreduction of UraniumBioreduction is driven by anaerobic bacteria such as certain strains of Geobacter and Shewanella, which use...
01:261° Amines to Diazonium or Aryldiazonium Salts: Diazotization with NaNO2 Overview
Nitrous acid and nitric acids are two types of acids containing nitrogen, among which nitrous acid is weaker than nitric acid. Nitrous acid with a pKa value of 3.37 ionizes in water to give a nitrite ion and the hydronium ion.
The nitrous acid is unstable. Hence, it is formed in situ from a solution of sodium nitrite and cold aqueous acids such as hydrochloric or sulfuric acid. In an acidic solution, the –OH group of nitrous acid undergoes protonation to give oxonium ion, followed by water loss...
The nitrous acid is unstable. Hence, it is formed in situ from a solution of sodium nitrite and cold aqueous acids such as hydrochloric or sulfuric acid. In an acidic solution, the –OH group of nitrous acid undergoes protonation to give oxonium ion, followed by water loss...
02:51Metal-Ligand Bonds
The hemoglobin in the blood, the chlorophyll in green plants, vitamin B-12, and the catalyst used in the manufacture of polyethylene all contain coordination compounds. Ions of the metals, especially the transition metals, are likely to form complexes.
In these complexes, transition metals form coordinate covalent bonds, a kind of Lewis acid-base interaction in which both of the electrons in the bond are contributed by a donor (Lewis base) to an electron acceptor (Lewis acid). The Lewis acid in...
In these complexes, transition metals form coordinate covalent bonds, a kind of Lewis acid-base interaction in which both of the electrons in the bond are contributed by a donor (Lewis base) to an electron acceptor (Lewis acid). The Lewis acid in...
01:26Radical Substitution: Hydrogenolysis of Alkyl Halides with Tributyltin Hydride
Radical substitution reactions can be used to remove functional groups from molecules. The hydrogenolysis of alkyl halides is one such reaction, where the weak Sn–H bond in tributyltin hydride reacts with alkyl halides to form alkanes. Here, the reagent Bu3SnH yields tributyltin halide as a byproduct.
The bonds formed in this reaction are stronger than the bonds broken, making it energetically favorable. The reaction follows a radical chain mechanism similar to radical halogenation reactions,...
The bonds formed in this reaction are stronger than the bonds broken, making it energetically favorable. The reaction follows a radical chain mechanism similar to radical halogenation reactions,...