Radiolytic Yield of UIV Oxidation into UVI: A New Mechanism for UV Reactivity in Acidic Solution

Atinault, E.; Waele, Vincent De; Naour, C. Le; Fattahi, Massoud; Mostafavi, Mehran

doi:10.1021/jp9051177

Cited by 25 publications

(29 citation statements)

References 23 publications

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“…The only peak in the 1.5 M HCl/glycerol (pH 0.1) spectra was at 370 nm, which is likely to be from the Cl 2 À ion chloride radical (Atinault et al, 2008). It may be that under these conditions the lifetime of the electron is shorter than the minimum measureable by our apparatus.…”

Section: Trapped Electronsmentioning

confidence: 69%

Colouring cryo-cooled crystals: online microspectrophotometry

McGeehan

Ravelli

Murray

et al. 2009

J Synchrotron Radiat

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X-rays can produce a high concentration of radicals within cryo-cooled macromolecular crystals. Some radicals have large extinction coefficients in the visible (VIS) range of the electromagnetic spectrum, and can be observed optically and spectrally. An online microspectrophotometer with high temporal resolution has been constructed that is capable of measuring UV/VIS absorption spectra (200-1100 nm) during X-ray data collection. The typical X-ray-induced blue colour that is characteristic of a wide range of cryoconditions has been identified as trapped solvated electrons. Disulphidecontaining proteins are shown to form disulphide radicals at millimolar concentrations, with absorption maxima around 400 nm. The solvated electrons and the disulphide radicals seem to have a lifetime in the range of seconds up to minutes at 100 K. The temperature dependence of the kinetics of X-ray-induced radical formation is different for the solvated electrons compared with the disulphide radicals. The online microspectrophotometer provides a technique complementary to X-ray diffraction for analysing and characterizing intermediates and redox states of proteins and enzymes.

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Section: Trapped Electronsmentioning

confidence: 69%

Colouring cryo-cooled crystals: online microspectrophotometry

McGeehan

Ravelli

Murray

et al. 2009

J Synchrotron Radiat

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“…We also assume complete dissociation of HAuCl 4 to determine the initial H + ion concentration (20 mM HAuCl 4 has pH ≈ 2.0). We include Cl − ions by adding the dominant reactions associated with Cl − to the simulation, 36 as detailed in the Supporting Information. This model includes unavoidable approximations.…”

mentioning

confidence: 99%

Control of Electron Beam-Induced Au Nanocrystal Growth Kinetics through Solution Chemistry

et al. 2015

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Measurements of solution-phase crystal growth provide mechanistic information that is helpful in designing and synthesizing nanostructures. Here, we examine the model system of individual Au nanocrystal formation within a defined liquid geometry during electron beam irradiation of gold chloride solution, where radiolytically formed hydrated electrons reduce Au ions to solid Au. By selecting conditions that favor the growth of well-faceted Au nanoprisms, we measure growth rates of individual crystals. The volume of each crystal increases linearly with irradiation time at a rate unaffected by its shape or proximity to neighboring crystals, implying a growth process that is controlled by the arrival of atoms from solution. Furthermore, growth requires a threshold dose rate, suggesting competition between reduction and oxidation processes in the solution. Above this threshold, the growth rate follows a power law with dose rate. To explain the observed dose rate dependence, we demonstrate that a reaction-diffusion model is required that explicitly accounts for the species H(+) and Cl(-). The model highlights the necessity of considering all species present when interpreting kinetic data obtained from beam-induced processes, and suggest conditions under which growth rates can be controlled with higher precision.

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“…At 90 min, the cell was opened to air and left in the dark for 30 min more. The spectrum registered the disappearance of the 963 nm peak due certainly to the fast oxidation or disproportionation of U(V) [24,31,[32][33][34][35]. Interestingly, a small decrease of the absorbance in the range 350-600 nm can be observed, which cannot be ascribed neither to U(V) [22][23][24] nor to U(IV) [17][18][19][20][21].…”

Section: Heterogeneous Photocatalytic Experimentsmentioning

confidence: 96%