Track topics on Twitter Track topics that are important to you
The photoluminescence of uranium(VI) is observed typically in the wavelength range 400-650 nm with the lifetime of several hundreds mus and is known to be quenched in the presence of various halide ions (case A) or alcohols (case B). Here, we show by density functional theory (DFT) calculations that the quenching involves an intermediate triplet excited state that exhibits uranium(V) character. The DFT results are consistent with previous experimental findings suggesting the presence of photoexcited uranium(V) radical pair during the quenching process. In the ground state of uranyl(VI) halides, the ligand contributions to the highest occupied molecular orbitals increase with the atomic number (Z) of halide ion allowing larger ligand-to-metal charge transfer (LMCT) between uranium and the halide ion. Consequently, a larger quenching effect is expected as Z increases. The quenching mechanism is essentially the same in cases A and B, and is driven by an electron transfer from the quencher to the UO(2)(2+) entity. The relative energetic stabilities of the triplet excited state define the "fate" of uranium, so that in case A uranium(V) is oxidized back to uranium(VI), while in case B uranium remains as pentavalent.
Institute of Radiochemistry, Forschungszentrum Dresden-Rossendorf (FZD), Bautzner Landstrasse 400, Dresden, 01328 Germany. S.Tsushima@fzd.de
This article was published in the following journal.
Name: Chemistry (Weinheim an der Bergstrasse, Germany)
The main aim of this study was to determine and evaluate urinary excretion of uranium in the general public of the Czech Republic. This value should serve as a baseline for distinguishing possible inc...
Uranium containing radioactive wastewater is seriously hazardous to the natural environment if it is being discharged directly. Herein, nano-flake like Fe loaded sludge carbon (Fe-SC) is synthesized b...
The endophyte Pseudomonas sp. XNN8 was separated from Typha orientalis which can secrete indole-3-acetic acid and 1-aminocyclopropane-1-carboxylate deaminase and siderophores and has strong resistance...
Depleted uranium is a mildly radioactive waste product that is stockpiled worldwide. The chemical reactivity of uranium complexes is well documented, including the stoichiometric activation of small m...
The former uranium mine Königstein (Saxony, Germany) is currently in the process of remediation by means of controlled underground flooding. Nevertheless, the flooding water has to be cleaned up by a...
This study argues that H.pylori infection, by increasing the production of reactive oxygen species, increases the utilization of dietary antioxidants(Vit E and Vit C) that serve in quenchi...
The mechanism by which colesevelam HCl lowers glucose is not known. Knowledge of the potential mechanism of action is important for defining the role of the drug among oral antidiabetic a...
An increase of plasma free fatty acids impairs insulin secretion and insulin sensitivity, thereby playing an important role in causing type 2 diabetes. Lipotoxicity plays an important ro...
Being a key player in Asthma, eosinophils constitute a potential target to interfere with the series of biological events leading to Asthma pathogenesis. In this proposal, the investigator...
Infection and trauma take a important role in the acute respiratory failure.There are different causes and degrees of inflammatory reaction in the critically ill patient. The inflammatory ...
Inorganic compounds that contain uranium as an integral part of the molecule.
Uranium. A radioactive element of the actinide series of metals. It has an atomic symbol U, atomic number 92, and atomic weight 238.03. U-235 is used as the fissionable fuel in nuclear weapons and as fuel in nuclear power reactors.
Radium. A radioactive element of the alkaline earth series of metals. It has the atomic symbol Ra, atomic number 88, and atomic weight 226. Radium is the product of the disintegration of uranium and is present in pitchblende and all ores containing uranium. It is used clinically as a source of beta and gamma-rays in radiotherapy, particularly BRACHYTHERAPY.
Nuclear reaction in which the nucleus of a heavy atom such as uranium or plutonium is split into two approximately equal parts by a neutron, charged particle, or photon.
Thorium. A radioactive element of the actinide series of metals. It has an atomic symbol Th, atomic number 90, and atomic weight 232.04. It is used as fuel in nuclear reactors to produce fissionable uranium isotopes. Because of its radioopacity, various thorium compounds are used to facilitate visualization in roentgenography.