A5040977195- Advanced oxidation water treatment
- Electrochemical Analysis and Applications
- Porphyrin and Phthalocyanine Chemistry
- Nitric Oxide and Endothelin Effects
- Free Radicals and Antioxidants
- Photochemistry and Electron Transfer Studies
- Catalytic Processes in Materials Science
- Electron Spin Resonance Studies
- Molecular Sensors and Ion Detection
- Metal-Catalyzed Oxygenation Mechanisms
- Lipid Membrane Structure and Behavior
- Atmospheric chemistry and aerosols
- Electrocatalysts for Energy Conversion
- Sulfur Compounds in Biology
- Electrochemical sensors and biosensors
- Radioactive element chemistry and processing
- Advanced Chemical Physics Studies
- CO2 Reduction Techniques and Catalysts
- Photosynthetic Processes and Mechanisms
- Ammonia Synthesis and Nitrogen Reduction
- TiO2 Photocatalysis and Solar Cells
- Chemistry and Chemical Engineering
- Neutrophil, Myeloperoxidase and Oxidative Mechanisms
- Radical Photochemical Reactions
- Lanthanide and Transition Metal Complexes
Brookhaven National Laboratory
2009-2021
Upton Hospital
2018-2019
Brookhaven College
2014
Washington State University
1995-2009
New York University
2002-2008
University of Notre Dame
2004
Argonne National Laboratory
2004
University of Alabama
2004
Pacific Northwest National Laboratory
2004
University of Alaska Fairbanks
2003
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTRapid reaction between peroxonitrite ion and carbon dioxide: Implications for biological activitySergei V. Lymar James K. HurstCite this: J. Am. Chem. Soc. 1995, 117, 34, 8867–8868Publication Date (Print):August 1, 1995Publication History Published online1 May 2002Published inissue 1 August 1995https://pubs.acs.org/doi/10.1021/ja00139a027https://doi.org/10.1021/ja00139a027research-articleACS PublicationsRequest reuse permissionsArticle...
Abstract Recommendations are made for standard potentials involving select inorganic radicals in aqueous solution at 25 °C. These recommendations based on a critical and thorough literature review also by performing derivations from various reports. The recommended data summarized tables of potentials, Gibbs energies formation, radical p K ’s, hemicolligation equilibrium constants. In all cases, current best estimates the uncertainties provided. An extensive set Data Sheets is appended that...
The thermodynamic properties of aqueous nitroxyl (HNO) and its anion (NO − ) have been revised to show that the ground state NO is triplet HNO in singlet has much lower acidity, pKa( 1 HNO/ 3 ≈ 11.4, than previously believed. These conclusions are accord with observed large differences between their reactivities toward O 2 NO. Laser flash photolysis was used generate by photochemical cleavage trioxodinitrate (Angeli's anion). spin-allowed addition produced peroxynitrite nearly...
Peroxynitrite ion (ONO2-) reacted rapidly with CO2 to form a short-lived intermediate provisionally identified as the ONO2CO2- adduct. This adduct was more reactive in tyrosine oxidation than ONO2- itself and produced 3-nitrotyrosine 3,3'-dityrosine major products. With excess, rate of formation independent concentration determined by The overall yield products also medium acidity; approximately 19% added converted under all reaction conditions. However, 3-nitrotyrosine/3,3'-dityrosine...
Yields of O2 formed during decomposition peroxynitrous acid (ONOOH) under widely varying medium conditions are compared to predictions based upon the assumption that reaction involves formation discrete •OH and •NO2 radicals as oxidizing intermediates. The kinetic model used includes all reactions •OH, •O2-, reactive nitrogen species known be important prevailing conditions; because rate constants for these have been independently measured, calculations contain no adjustable fitting...
Inorganic radicals, such as superoxide and hydroxyl, play an important role in biology. Their tendency to oxidize or reduce other compounds has been studied by pulse radiolysis; electrode potentials can be derived when equilibrium is established with a well-known reference compound. An IUPAC Task Group evaluated the literature produced recommended standard for couples (O2/O2·-), (HO·, H+/H2O), (O3/O3·-), (Cl2/Cl2·-), (Br2·-/2Br-), (NO2·/NO2-), (CO3·-/CO32-).
Using a new technique, which combines pulse radiolysis with nanosecond time-resolved infrared (TRIR) spectroscopy in the condensed phase, we have conducted detailed kinetic and mechanistic investigation of formation Mn-based CO2 reduction electrocatalyst, [Mn((t)Bu2-bpy)(CO)3]2 ((t)Bu2-bpy = 4,4'-(t)Bu2-2,2'-bipyridine), acetonitrile. The use TRIR allowed, for first time, direct observation all intermediates involved this process. Addition excess [(n)Bu4N][HCO2] to an acetonitrile solution...
In neutral bicarbonate-containing solutions, the predominant pathway for peroxynitrite decomposition was CO2-catalyzed formation of nitrate ion; that is, CO2 regenerated in process. When nitrite ion present, HCO3- also formed during ONO2- decomposition. The data could be reproduced by a kinetic model wherein reactive intermediate from and oxidizes NO2- to •NO2, which subsequently hydrolyzes bimolecular reaction form NO3- regenerate NO2-. Carbon dioxide catalyzed one-electron oxidations...
A pulse radiolysis study which uses a flow system to irradiate mixtures of H2CO3 and HCO3- within 50 ms their formation has demonstrated that the carbonate radical is strong acid, pKa < 0, contrary published reports high pKas. The rate constant for reaction hydroxyl with 7 × 104 M-1 s-1 at about 5 °C.
A novel, highly efficient, and stable water oxidation catalyst was prepared by a pH-controlled adsorption of Co(II) on ∼10 nm diameter silica nanoparticles. lower limit ∼300 s–1 per cobalt atom for the turnover frequency in oxygen evolution estimated, which attests to very high catalytic activity. Electron microscopy revealed that is adsorbed SiO2 nanoparticle surfaces as small (1–2 nm) clusters Co(OH)2. This optically transparent over entire UV–vis range thus suitable mechanistic...
First IR detection of CO<sub>2</sub>˙<sup>−</sup> in acetonitrile, produced by radiation-induced CO<sub>2</sub> reduction and oxidation formate.
Mechanistic predictions, based upon the assumption that free •OH and •NO2 radicals are formed as intermediates during ONOOH decay, were tested using inorganic radical scavengers. Both rates yields of Fe(CN)64- IrCl63- oxidation by independent their concentrations in submillimolar range. A 55 ± 7% Fe(CN)63- yield 25 3% IrCl62- measured at pH 5.7, 22 °C. ratio close to 2 is expected, because, two produced, only can rapidly oxidize IrCl63-. The competition kinetic studies demonstrated relative...
The first mechanistic study of a spin-forbidden proton-transfer reaction in aqueous solution is reported. Laser flash photolysis alkaline trioxodinitrate (N2O32-, Angeli's anion) used to generate nitroxyl anion its excited singlet state (1NO-). Through rapid partitioning between protonation by water and electronic relaxation, 1NO- produces 1HNO (ground state, yield 96%) 3NO- 4%), which comprise unique conjugate acid−base couple with different ground-state multiplicities. Using the large...
The pulse radiolysis of aqueous NO has been reinvestigated, the variances with prior studies are discussed, and a mechanistic revision is suggested. Both hydrated electron hydrogen atom reduce to yield ground-state triplet (3)NO(-) singlet (1)HNO, respectively, which further react produce N(2)O(2)(-) radical, albeit very different specific rates, k((3)NO(-) + NO) = (3.0 +/- 0.8) x 10(9) k((1)HNO (5.8 0.2) 10(6) M(-)(1) s(-)(1). These reactions occur much more rapidly than spin-forbidden...
Peroxynitrite decay in weakly alkaline media occurs by two concurrent sets of pathways which are distinguished their reaction products. One set leads to net isomerization NO3- and the other decomposition O2 plus NO2-. At sufficiently high peroxynitrite concentrations, half-time becomes concentration-independent approaches a limiting value predicted mechanism is initiated unimolecular homolysis peroxo O−O bond, i.e., following reaction: ONOOH → •OH + •NO2. This dynamical behavior excludes...
The toxicity of peroxynitrite toward Escherichia coli (expressed as LD50, the concentration required to kill 50% bacteria) was found be independent bacterial cell densities over a wide experimental range, spanning 106−1010 colony-forming units/mL; magnitude LD50 also pH-independent range pH 5.9−8.3. This highly unusual behavior can quantitatively reproduced by dynamical model in which (i) ONO2H is identified toxic form oxidant and (ii) bulk added decays nitrate ion under these conditions....
All major properties of the aqueous hyponitrite radicals (ONNO- and ONNOH), adducts nitric oxide (NO) nitroxyl (3NO- 1HNO), are revised. In this work, produced by oxidation various species in 2−14 pH range with OH, N3, or SO4- radicals. The estimated rate constants OH 4 × 107, 4.2 109, 8.8 109 M-1 s-1 for oxidations HONNOH, HONNO-, ONNO2-, respectively. N3 + ONNO2- HONNO- 1.1 6.4 108 s-1, ONNO- radical exhibits a strong characteristic absorption spectrum maxima at 280 420 nm (ε280 = 7.6 103...
ADVERTISEMENT RETURN TO ISSUEPREVOpen ForumNEXTRadical Nature of Peroxynitrite ReactivitySergei V. Lymar and James K. HurstView Author Information Department Chemistry, Washington State University, Pullman, 99164-4630, Brookhaven National Laboratory, Upton, New York 11973-5000 Cite this: Chem. Res. Toxicol. 1998, 11, 7, 714–715Publication Date (Web):July 20, 1998Publication History Received14 April 1998Published online20 July inissue 1...