DOCSLIB.ORG

Free Radical Nomenclature, Suggestions

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Free Radical Nomenclature, Suggestions FRRB Free Radical Nomenclature Page 1 of 8 Free Radical Nomenclature, Suggestions Garry R. Buettner, Ph.D. Free Radical and Radiation Biology Program Med Labs B180K The University of Iowa Iowa City, IA 52242-1181 2018.01.17 The purpose of this document is to provide an easy reference to some of the language of Redox Radical Biology. We provide here a beginning guideline to nomenclature and notation for free radicals and related redox species. The International Union of Pure and Applied Chemistry (IUPAC) does not provide suggestions on all abbreviations we might use; attached are the suggestions of the FRRB Program at The University of Iowa. Guidelines for nomenclature in Free Radical Biology can be found in [1, 2, 3, 4, 5 and references therein]. I. Free Radical and Oxidant Notation and Nomenclature In chemical formulae, as well as when using abbreviations, a free radical is denoted by a superscript dot to the right preceding any charge. This placement of the dot will not interfere with indication of mass number, atomic number, or composition. – – H O2 CO2 HO H3C NO 2 O2 would be the radical notation for ground state dioxygen, O2. Table 1. Formulae and IUPAC Recommended Names of Simple Compounds Containing C, H, N, and O in Free Radical Biology Species Common Systematic Name Alternative and Name Comments CO carbon monoxide carbon monoxide oxidomethanediyl CO2 carbon dioxide carbon dioxide dioxidomethane carbon dioxide CO – dioxidocarbonate (•1–) oxidooxomethyl radical 2 radical anion •– CO3 carbonate radical trioxidocarbonate(•1–) H hydrogen atom monohydrogen(•) H+ proton hydron, monohydrogen(1+) not to be confused with H• H2O water dihydrogen monoxide oxidane H2O2 hydrogen peroxide dihydridodioxide dioxidane H3C methyl radical HNO nitroxyl nitrosyl hydride HNO2 nitrous acid HNO3 nitric acid Buettner GR Page 1 FRRB Free Radical Nomenclature Page 2 of 8 HO hydroxyl radical hydridooxygen(•) oxidanyl dioxidanide, – hydrogendioxide(1-); HO hydridodioxygen (1-) 2 hydrogenperoxide(1-); hydroperoxide is not recommended hydroperoxyl, but is dioxidonyl, hydrodioxyl, perhydroxyl hydridodioxygen(•) HO2 obsolete does not make sense hydrogen trioxide HO • hydridotrioxygen(•) trioxidanyl 3 radical HOCO• hydroxidooxidocarbon(•) Protonated carbon dioxide radical • HOCO 2 hydroxidodioxidocarbon(•) Protonated carbonate radical HOCO• hydroxidooxidocarbon(•) • HOCO 2 hydroxidodioxidocarbon(•) HOCl hypochlorous acid hydrogenoxidochlorate HOBr hypobromous acid hydrogenoxidobromate HOI hypoiodous acid hydrogenoxidoiodate hypothiocyanous HOSCN hydrogenoxidothiocyanate acid nitroxyl, protonated - HNO See [6] for chemistry and NO form of NO- HON2• hydroxidonitrogen(2•)(triplet) hydrogen oxidonitrate(2•)(triplet) HOOCO• (hydridodioxido)oxidocarbon(•) HOONO peroxynitrous acid hydrogenoxidoperoxidonitrate nitrosodioxidane H2S hydrogen sulfide dihydrogen sulfide HSNO thionitrous acid •– (NO)2 bis(oxidonitrate)(N – N)(•1-) N2O nitrous oxide dinitrogen monoxide •– N2O oxidodinitrate(•1-) N2O3 dinitrogen trioxide N3 azidyl radical trinitrogen(2N – N)(•) nitric oxide, but is oxidonitrogen(•) oxoazanyl, nitrogen monoxide NO obsolete NO+ nitrosonium ion NO- nitroxyl anion conjugate base of HNO NO(2•)– Nitroxy ?? oxidonitrate(2•1–) (triplet) – NO2 nitrite dioxidonitrate(1–) NO2 nitrogen dioxide dioxidonitrogen(•) •2– NO2 dioxidonitrate(•2-) – NO3 nitrate trioxidonitrate(-) NO3 nitrogen trioxide trioxidonitrogen(•) nitrosoxidanyl •2– NO3 trioxidonitrate(•2-) Buettner GR Page 2 FRRB Free Radical Nomenclature Page 3 of 8 • O– radical anion of HO oxide(•1-) oxidanidyl – O2 superoxide dioxide(•1-) dioxidanidyl •+ O2 dioxygen(•1+) 2 oxygen, usually O2 dioxygen (triplet) dioxidanediyl written as O2 O3 ozone trioxygen – O3 ozonide trioxide(•1-) trioxidanidyl OCl– hypochlorite oxidochlorate(1-) OBr– hypobromite oxidobromate(1-) OI– hypoiodite oxidoiodate(1-) OSCN– hypothiocyanate oxidothiocyanate(1-) OCOO– or – carbonate radical (dioxido)oxidocarbonate(•1–) CO3 ONOO– peroxynitrite oxidoperoxidonitrate(1-) nitrosodioxidanide ONOOH peroxynitrous acid hydrogen-oxidoperoxinitrate nitrosodioxidane ONOO (dioxido)oxidonitrogen(•) nitrosodioxidanyl II. Free Radical Nomenclature You Need to Know Table 2 Common Abbreviations Species/Abbreviation* Name ascorbate, general; ascorbic acid; ascorbate monoanion; ascorbate radical OH OH OH O HO O O HO O pK1 = 4.1 O pK2 = 11.8 HO O HO OH O OH O O AscH - 2- – – 2 AscH Asc Asc; AscH2, AscH ; Asc OH OH O O HO O HO O + R + RH O OH O O AscH Asc CAT catalase Desferalâ trade name for deferrioxamine mesylate Buettner GR Page 3 FRRB Free Radical Nomenclature Page 4 of 8 H O O H N C NH C NH (CH2)5 (CH2)2 (CH ) (CH2) 2 5 (CH2)5 CH3 N C N C N C HO O HO O HO O Deferrioxamine (Desferal) 5,5-dimethyl-pyrroline-1-oxide, a spin trap H + R N DMPO N R O O DMPO Nitroxide Radical (Nitrone Spin Trap) (Aminoxyl Spin Adduct) diethylenetriaminepentaacetic acid (Shown is the completely ionized species.) O O DTPA or DETAPAC O C H2C CH2 C O N (CH2)2 N (CH2)2 N O C H2C CH2 C O CH2 C O O O O EDRF endothelium-derived relaxing factor ethylenediaminetetraacetic acid (Shown is the completely ionized species.) O O EDTA O C H2C CH2 C O N CH2 CH2 N O C H2C CH2 C O O O EPR electron paramagnetic resonance ESR electron spin resonance, identical with EPR G gauss GPx glutathione peroxidase glutathione disulfide reductase; often referred to as glutathione GR reductase (a misnomer) Grx glutaredoxin GS• glutathiyl radical or glutathionyl radical Buettner GR Page 4 FRRB Free Radical Nomenclature Page 5 of 8 O NH3 O H O O C CH CH2 CH2 C NH C C NH CH2 C O O CH2 S Glutathione; not reduced glutathione, a misnomer O NH3 O H O O C CH CH2 CH2 C NH C C NH CH2 C O O GSH CH2 SH glutamate cysteine glycine GSSG glutathione disulfide; not oxidized glutathione, a misnomer 2GSH à GSSG + 2e- + H+ GST glutathione S transferase H+ proton, hydron; not to be confused with H• LDL low density lipoprotein MDA Malondialdehyde O O O OH NBT nitroblue tetrazolium H3CO OCH3 N N N N N N N N O N NO 2 2 NOS nitric oxide synthase 1 O2 singlet oxygen OH– hydroxide anion, not to be confused with HO• PBN a-phenyl-N-tert-butyl nitrone, a spin trap Buettner GR Page 5 FRRB Free Radical Nomenclature Page 6 of 8 O CH3 CH N C CH3 CH 3 Prxd often Prx peroxiredoxin PhGPx phospholipid hydroperoxide glutathione peroxidase (GPx-4) POBN a-[4-pyridyl 1-oxide]-N-tert-butyl nitrone, a spin trap O CH3 O N CH N C CH3 CH 3 PUFA polyunsaturated fatty acid, for example 14 11 8 5 OH H11C5 (CH2)3 C O arachidonic acid RNS reactive nitrogen species RO alkoxyl radical; not alkoxy ROO• alkyl dioxygen(•), alkyldioxyl, alkylperoxyl radical; not peroxy ROOH alkyl hydroperoxide ROS reactive oxygen species R-SH thiol R-S- thiolate anion- R-SOH sulfenic acid R-SO2H sulfinic acid R-SO3H sulfonic acid SOD superoxide dismutase CuZnSOD copper,zinc-superoxide dismutase (SOD-1) MnSOD manganese-superoxide dismutase (SOD-2) FeSOD iron-superoxide dismutase ECSOD extracellular superoxide dismutase (SOD-3) TBARS thiobarbituric acid reactive substances Trx thioredoxin * These are commonly used abbreviations. Others appear in the literature. Buettner GR Page 6 FRRB Free Radical Nomenclature Page 7 of 8 III. Enzyme Reactions You Must Know to Understand Free Radical Biology A. The reaction for superoxide dismutase (SOD) is: SOD – – + O2 + O2 + 2 H ¾¾¾® O2 + H2O2 B. The reactions for catalase (CAT) are: CAT 2 H2O2 ¾¾¾® O2 + 2 H2O Catalytic Rxn CAT H2O2 + DH2 ¾¾¾® D + 2 H2O Peroxidatic Rxn C. The reaction for glutathione peroxidase (GPx) is: GPx ROOH + 2 GSH ¾¾¾® ROH + H2O + GSSG where R = H is allowed. D. An overview of the reaction of the peroxiredoxins is: Prx H2O2 + Trx-(SH)2 ¾¾¾® 2 H2O + Trx(S-S) E. Overview of Antioxidant network Buettner GR Page 7 FRRB Free Radical Nomenclature Page 8 of 8 This overview is from [7]. End IV. References 1 Koppenol WH. (2000) Names for inorganic radicals. Pure Appl Chem. 72:437-446. http://www.iupac.org/publications/pac/2000/7203/7203pdf/7203koppenol_437.pdf 2 Powell WH. (1993) Revised nomenclature for radicals, ions, radical ions and related species. Found at: http://www.chem.qmul.ac.uk/iupac/ions 3 Koppenol WH. (1990) What is in a name? Rules for radicals. Free Radic Biol. Med 9:225-227. http://dx.doi.org/10.1016/0891-5849(90)90032-E 4 Traynham JG. (1986) A short guide to nomenclature of radicals, radical ions, iron-oxygen complexes and polycyclic aromatic hydrocarbons. Adv Free Radic Bio Med. 2:191-209. http://dx.doi.org/10.1016/S8755-9668(86)80029-1 5 Koppenol WH. (2002) NO nomenclature? Nitric Oxide Biol Chem. 6:96-98. http://dx.doi.org/10.1006/niox.2001.0406 6 Fukuto JM, Switzer CH, Miranda KM, Wink DA. (2005) Nitroxyl (HNO): chemistry, biochemistry, and pharmacology. Annu Rev Pharmacol Toxicol. 45:335-55. PMID: 15822180 http://dx.doi.org/doi:10.1146/annurev.pharmtox.45.120403.095959 7 Ng CF, Schafer FQ, Buettner GR, Rodgers VGJ. (2007) The rate of cellular hydrogen peroxide removal shows dependency on GSH: Mathematical insight into in vivo H2O2 and GPx concentrations. Free Rad Res. 41:1201-1211. PMID: 17886026 http://dx.doi.org/10.1080/10715760701625075 Buettner GR Page 8 .
Load more

Recommended publications
  • A Biochemical Rationale for the Discrete Behavior of Nitroxyl and Nitric Oxide in the Cardiovascular System
    A biochemical rationale for the discrete behavior of nitroxyl and nitric oxide in the cardiovascular system Katrina M. Miranda*†‡, Nazareno Paolocci§, Tatsuo Katori§, Douglas D. Thomas*, Eleonora Ford¶, Michael D. Bartbergerʈ, Michael G. Espey*, David A. Kass§, Martin Feelisch**, Jon M. Fukuto¶, and David A. Wink*† *Radiation Biology Branch, Building 10, Room B3-B69, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892; §Division of Cardiology, Department of Medicine, The Johns Hopkins Medical Institutions, Baltimore, MD 21287; ¶Department of Molecular and Medical Pharmacology, Center for the Health Sciences, University of California, Los Angeles, CA 90095; ʈDepartment of Chemistry and Biochemistry, University of California, Los Angeles, CA 90095; and **Department of Molecular and Cellular Physiology, Louisiana State University Health Sciences Center, Shreveport, LA 71130 Edited by Louis J. Ignarro, University of California School of Medicine, Los Angeles, CA, and approved May 20, 2003 (received for review February 20, 2003) The redox siblings nitroxyl (HNO) and nitric oxide (NO) have often cellular thiol functions (14, 15). Conversely, NO reacts only indi- been assumed to undergo casual redox reactions in biological sys- rectly with thiols after RNOS formation (17). tems. However, several recent studies have demonstrated distinct Contrasting effects are also apparent in vivo or ex vivo,for pharmacological effects for donors of these two species. Here, infu- example in models of ischemia reperfusion injury. Exposure to NO sion of the HNO donor Angeli’s salt into normal dogs resulted in donors at the onset of reperfusion provides protection against elevated plasma levels of calcitonin gene-related peptide, whereas reperfusion injury in the heart and other organs (18–20).
    [Show full text]
  • Depa1'tment of Physical Chemistry Isl'ael
    .. ANNUAL PROGRESS REPORT C00-3221-67 (For the period September 79 - July 80) Under Contract No. DOE/EV/03221 on THE NATURE OF OXYGEN CONTAINING RADICALS IN RADIATION CHEMISTRY AND PHOTOCHEMISTRY OF AQUEOUS SOLUTIONS Submitted by PROFESSOR GIDON CZAPSKI Depa1'tment of Physical Chemistry The Hebl'eW Univel'sity~ Jerusalem~ Isl'ael IJISTRIBUTIOJI OF THIS DOCUMENT IS UNUMITEJJ DISCLAIMER This report was prepared as an account of work sponsored by an agency of the United States Government. Neither the United States Government nor any agency Thereof, nor any of their employees, makes any warranty, express or implied, or assumes any legal liability or responsibility for the accuracy, completeness, or usefulness of any information, apparatus, product, or process disclosed, or represents that its use would not infringe privately owned rights. Reference herein to any specific commercial product, process, or service by trade name, trademark, manufacturer, or otherwise does not necessarily constitute or imply its endorsement, recommendation, or favoring by the United States Government or any agency thereof. The views and opinions of authors expressed herein do not necessarily state or reflect those of the United States Government or any agency thereof. DISCLAIMER Portions of this document may be illegible in electronic image products. Images are produced from the best available original document. ANNUAL PROGRESS REPORT C00-3221-67 (For the period September 79 - July 80) Und~r Contract No. DOE/EV/03221·· on THE NATURE OF OXYGEN CONTAINING RADICALS IN RADIATION CHEMISTRY AND PHOTOCHEMISTRY OF AQUEOUS SOLUTIONS Submitted by PROFESSOR GIDON CZAPSKI lh~s book was ~repared as an account of work sponsored by an agency of the United States Government :!:~; the ~~•ted Stat~ ~nment nor any agency thereof, nor any of their employees, makes an~ v.
    [Show full text]
  • The Ins and Outs of Dechlorination
    The Ins and Outs of Dechlorination If you plan on using a municipal water supply for chlorine is added to water, it will first react with growing fish you will require a dechlorination step any reducing agents, including any ammonia that in your water treatment process. Most municipal may be present. Hypochlorous acid reacts with water systems use chlorine or chloramine (a com- ammonia to form chloramines as follows: bination of chlorine and ammonia) to render the water safe for human consumption. While rela- HOCL + NH3 _ H2O + NH2Cl (monochloramine) tively harmless to humans in minute amounts, HOCL + NH2Cl _ H2O + NHCl2 (dichloramine) chlorine can be deadly to fish. In order to under- HOCL + NHCl2 _ H2O + NCl3 (trichloramine) BY: CARLA MACQUARRIE stand how to dechlorinate water, there must first AND SEAN WILTON be an understanding of how and why chlorine is The formation of chloramines is also dependent used as a disinfecting agent. on pH and temperature, as well as on the concen- tration of ammonia. With the added presence of Chlorine is water soluble gas (7160 mg/L these chloramines, the available chlorine is at 20°C and 1atm) that hydrolyzes rapidly referred to as combined available chlorine (CAC). to form hypochlorous acid (HOCl). This When these reactions are complete, residual reaction forms the basis for the applica- chlorine will accumulate, either in the form of FAC tion of chlorine as a disinfectant and oxi- or CAC. Total residual chlorine refers to the sum of dant as follows: the free and combined forms of residual chlorine. As a disinfectant, the FAC component is more Cl2 + H20 —> HOCl + H+ + Cl- effective than the CAC – this is because chlo- ramines are considered to have only a moderate The by-product, hypochlorous acid(HOCl) biocidal activity against bacteria and a low bioci- ionizes to produce the hypochlorite (OCl-) dal activity against viruses and cysts.
    [Show full text]
  • Impact of Sulfur Dioxide Oxidation by Stabilized Criegee Intermediate on Sulfate 2 3 Golam Sarwar 1*, Heather Simon 2, Kathleen Fahey 1, Rohit Mathur 1,Wendy S
    1 Impact of sulfur dioxide oxidation by Stabilized Criegee Intermediate on sulfate 2 3 Golam Sarwar 1*, Heather Simon 2, Kathleen Fahey 1, Rohit Mathur 1,Wendy S. Goliff 3,William R. 4 Stockwell 4 5 6 7 1Atmospheric Modeling and Analysis Division, National Exposure Research Laboratory, U.S. Environmental 8 Protection Agency, RTP, NC 27711, USA. 9 10 2Office of Air Quality Planning and Standards, U.S. Environmental Protection Agency, Research Triangle Park, 11 North Carolina, USA. 12 13 3College of Engineering Center for Environmental Research and Technology, University of California at Riverside, 14 Riverside, CA 92507, USA. 15 16 4Department of Chemistry, Howard University, Washington, DC 20059, USA. 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 ______________________________ 45 46 *Corresponding author : Golam Sarwar, U.S. EPA, 109 T.W. Alexander Drive, Research 47 Triangle Park, NC 27711, USA; Tel.: 919-541-2669; fax: 919-541-1379; e-mail : 48 [email protected] 49 - 1 - 50 Abstract 51 We revise the Carbon Bond chemical mechanism to explicitly represent three Stabilized Criegee 52 Intermediates (SCIs) and their subsequent reactions with sulfur dioxide, water monomer, and 53 water dimer, and incorporate the reactions into the Community Multiscale Air Quality model. 54 The reaction of sulfur dioxide with SCI produces sulfuric acid which partitions into sulfate. We 55 examine the impact of sulfur dioxide oxidation by SCI on sulfate using two different measured 56 rate constants for the reaction of sulfur dioxide and SCI.
    [Show full text]
  • Hypochlorous Acid Handling
    Hypochlorous Acid Handling 1 Identification of Petitioned Substance 2 Chemical Names: Hypochlorous acid, CAS Numbers: 7790-92-3 3 hypochloric(I) acid, chloranol, 4 hydroxidochlorine 10 Other Codes: European Community 11 Number-22757, IUPAC-Hypochlorous acid 5 Other Name: Hydrogen hypochlorite, 6 Chlorine hydroxide List other codes: PubChem CID 24341 7 Trade Names: Bleach, Sodium hypochlorite, InChI Key: QWPPOHNGKGFGJK- 8 Calcium hypochlorite, Sterilox, hypochlorite, UHFFFAOYSA-N 9 NVC-10 UNII: 712K4CDC10 12 Summary of Petitioned Use 13 A petition has been received from a stakeholder requesting that hypochlorous acid (also referred 14 to as electrolyzed water (EW)) be added to the list of synthetic substances allowed for use in 15 organic production and handling (7 CFR §§ 205.600-606). Specifically, the petition concerns the 16 formation of hypochlorous acid at the anode of an electrolysis apparatus designed for its 17 production from a brine solution. This active ingredient is aqueous hypochlorous acid which acts 18 as an oxidizing agent. The petitioner plans use hypochlorous acid as a sanitizer and antimicrobial 19 agent for the production and handling of organic products. The petition also requests to resolve a 20 difference in interpretation of allowed substances for chlorine materials on the National List of 21 Allowed and Prohibited Substances that contain the active ingredient hypochlorous acid (NOP- 22 PM 14-3 Electrolyzed water). 23 The NOP has issued NOP 5026 “Guidance, the use of Chlorine Materials in Organic Production 24 and Handling.” This guidance document clarifies the use of chlorine materials in organic 25 production and handling to align the National List with the November, 1995 NOSB 26 recommendation on chlorine materials which read: 27 “Allowed for disinfecting and sanitizing food contact surfaces.
    [Show full text]
  • A Study of Organosilicon Free Radicals Jay Stephen Curtice Iowa State College
    Iowa State University Capstones, Theses and Retrospective Theses and Dissertations Dissertations 1954 A study of organosilicon free radicals Jay Stephen Curtice Iowa State College Follow this and additional works at: https://lib.dr.iastate.edu/rtd Part of the Organic Chemistry Commons, and the Physical Chemistry Commons Recommended Citation Curtice, Jay Stephen, "A study of organosilicon free radicals " (1954). Retrospective Theses and Dissertations. 13411. https://lib.dr.iastate.edu/rtd/13411 This Dissertation is brought to you for free and open access by the Iowa State University Capstones, Theses and Dissertations at Iowa State University Digital Repository. It has been accepted for inclusion in Retrospective Theses and Dissertations by an authorized administrator of Iowa State University Digital Repository. For more information, please contact [email protected]. A STUDY OF ORGANOSILICON FREE RADICALS by Jay Stephen Curtice A Dissertation Sul»nitted to the Graduate Faculty in Partial Fulfillment of The Requirements for the Degree of DOCTOR OF PHILOSOPHY Major Subject: Physical Organic Chemistry Approved; Signature was redacted for privacy. Signature was redacted for privacy. In CJiiarge of Major Work Signature was redacted for privacy. Head of Major DepartMnt Signature was redacted for privacy. Dean of Graduate College Iowa State College 195^ UMI Number: DP12662 INFORMATION TO USERS The quality of this reproduction is dependent upon the quality of the copy submitted. Broken or indistinct print, colored or poor quality illustrations and photographs, print bleed-through, substandard margins, and improper alignment can adversely affect reproduction. In the unlikely event that the author did not send a complete manuscript and there are missing pages, these will be noted.
    [Show full text]
  • Rate Constants for Reactions Between Iodine- and Chlorine-Containing Species: a Detailed Mechanism of the Chlorine Dioxide/Chlorite-Iodide Reaction†
    3708 J. Am. Chem. Soc. 1996, 118, 3708-3719 Rate Constants for Reactions between Iodine- and Chlorine-Containing Species: A Detailed Mechanism of the Chlorine Dioxide/Chlorite-Iodide Reaction† Istva´n Lengyel,‡ Jing Li, Kenneth Kustin,* and Irving R. Epstein Contribution from the Department of Chemistry and Center for Complex Systems, Brandeis UniVersity, Waltham, Massachusetts 02254-9110 ReceiVed NoVember 27, 1995X Abstract: The chlorite-iodide reaction is unusual because it is substrate-inhibited and autocatalytic. Because - analytically pure ClO2 ion is not easily prepared, it was generated in situ from the rapid reaction between ClO2 and I-. The resulting overall reaction is multiphasic, consisting of four separable parts. Sequentially, beginning with mixing, these parts are the (a) chlorine dioxide-iodide, (b) chlorine(III)-iodide, (c) chlorine(III)-iodine, and (d) hypoiodous and iodous acid disproportionation reactions. The overall reaction has been studied experimentally and by computer simulation by breaking it down into a set of kinetically active subsystems and three rapidly established - equilibria: protonations of chlorite and HOI and formation of I3 . The subsystems whose kinetics and stoichiometries were experimentally measured, remeasured, or which were previously experimentally measured include oxidation of - iodine(-1,0,+1,+3) by chlorine(0,+1,+3), oxidation of I by HIO2, and disproportionation of HOI and HIO2. The final mechanism and rate constants of the overall reaction and of its subsystems were determined by sensitivity analysis and parameter fitting of differential equation systems. Rate constants determined for simpler reactions were fixed in the more complex systems. A 13-step model with the three above-mentioned rapid equilibria fits the - -3 - -3 - - overall reaction and all of its subsystems over the range [I ]0 < 10 M, [ClO2 ]0 < 10 M, [I ]0/[ClO2 ]0 ) 3-5, pH ) 1-3.5, and 25 °C.
    [Show full text]
  • Synthesis of Phosphine-Functionalized Metal
    DISS. ETH NO. 23507 Understanding and improving gold-catalyzed formic acid decomposition for application in the SCR process A thesis submitted to attain the degree of DOCTOR OF SCIENCES of ETH ZURICH (Dr. sc. ETH Zurich) presented by MANASA SRIDHAR M. Sc. in Chemical Engineering, University of Cincinnati born on 12.12.1987 citizen of India accepted on the recommendation of Prof. Dr. Jeroen A. van Bokhoven, examiner Prof. Dr. Oliver Kröcher, co-examiner Prof. Dr. Christoph Müller, co-examiner 2016 “anything can happen, in spite of what you’re pretty sure should happen.” Richard Feynman Table of content Abstract .............................................................................................................................. II die Zusammenfassung ..................................................................................................... VI Chapter 1 Introduction .......................................................................................................... 1 Chapter 2 Methods ............................................................................................................ 15 Chapter 3 Unique selectivity of Au/TiO2 for ammonium formate decomposition under SCR- relevant conditions ............................................................................................................. 25 Chapter 4 Effect of ammonia on the decomposition of ammonium formate and formic acid on Au/TiO2 .............................................................................................................................
    [Show full text]
  • Warning: the Following Lecture Contains Graphic Images
    What the новичок (Novichok)? Why Chemical Warfare Agents Are More Relevant Than Ever Matt Sztajnkrycer, MD PHD Professor of Emergency Medicine, Mayo Clinic Medical Toxicologist, Minnesota Poison Control System Medical Director, RFD Chemical Assessment Team @NoobieMatt #ITLS2018 Disclosures In accordance with the Accreditation Council for Continuing Medical Education (ACCME) Standards, the American Nurses Credentialing Center’s Commission (ANCC) and the Commission on Accreditation for Pre-Hospital Continuing Education (CAPCE), states presenters must disclose the existence of significant financial interests in or relationships with manufacturers or commercial products that may have a direct interest in the subject matter of the presentation, and relationships with the commercial supporter of this CME activity. The presenter does not consider that it will influence their presentation. Dr. Sztajnkrycer does not have a significant financial relationship to report. Dr. Sztajnkrycer is on the Editorial Board of International Trauma Life Support. Specific CW Agents Classes of Chemical Agents: The Big 5 The “A” List Pulmonary Agents Phosgene Oxime, Chlorine Vesicants Mustard, Phosgene Blood Agents CN Nerve Agents G, V, Novel, T Incapacitating Agents Thinking Outside the Box - An Abbreviated List Ammonia Fluorine Chlorine Acrylonitrile Hydrogen Sulfide Phosphine Methyl Isocyanate Dibotane Hydrogen Selenide Allyl Alcohol Sulfur Dioxide TDI Acrolein Nitric Acid Arsine Hydrazine Compound 1080/1081 Nitrogen Dioxide Tetramine (TETS) Ethylene Oxide Chlorine Leaks Phosphine Chlorine Common Toxic Industrial Chemical (“TIC”). Why use it in war/terror? Chlorine Density of 3.21 g/L. Heavier than air (1.28 g/L) sinks. Concentrates in low-lying areas. Like basements and underground bunkers. Reacts with water: Hypochlorous acid (HClO) Hydrochloric acid (HCl).
    [Show full text]
  • Hidden Complexities in the Reaction of H2O2 and HNO Revealed by Ab Initio Quantum Chemical Cite This: Phys
    PCCP PAPER Hidden complexities in the reaction of H2O2 and HNO revealed by ab initio quantum chemical Cite this: Phys. Chem. Chem. Phys., 2017, 19, 29549 investigations† Daniel Beckett, Marc Edelmann, Jonathan D. Raff and Krishnan Raghavachari* Nitroxyl (HNO) and hydrogen peroxide have both been implicated in a variety of reactions relevant to environmental and physiological processes and may contribute to a unique, unexplored, pathway for the production of nitrous acid (HONO) in soil. To investigate the potential for this reaction, we report an in-depth investigation of the reaction pathway of H2O2 and HNO forming HONO and water. We find the breaking of the peroxide bond and a coupled proton transfer in the first step leads to hydrogen nitryl (HNO2) and an endogenous water, with an extrapolated NEVPT2 (multireference perturbation theory) barrier of 29.3 kcal molÀ1. The first transition state is shown to possess diradical character linking the far peroxide oxygen to the bridging, reacting, peroxide oxygen. The energy of this first step, when calculated using hybrid density functional theory, is shown to depend heavily on the amount of Hartree–Fock exchange in the functional, with higher amounts leading to a higher barrier and more diradical character. Additionally, high amounts of spin contamination cause CCSD(T) to significantly overestimate the TS1 barrier with a value of 36.2 kcal molÀ1 when using the stable UHF wavefunction as the reference wavefunction. However, when using the restricted Hartree–Fock reference wavefunction, the TS1 CCSD(T) energy is lowered to yield a barrier of 31.2 kcal molÀ1, in much better agreement with the Received 29th August 2017, NEVPT2 result.
    [Show full text]
  • DBDMH As a Processing Aid to the List of Allowed Substances in the National Organic Program
    CBI Deleted ALBEMARLE CORPORATION Petition to add DBDMH as a processing aid to the List of Allowed Substances in the National Organic Program This petition contains Confidential Business Information. This includes “trade secrets” related to the production process and quality control tests and data. This information is commercially valuable, used in Albemarle business and maintained in secrecy. Introduction Hypobromous acid (HOBr) derived from 1,3-dibromo-5,5-dimethylhydantoin (DBDMH, CAS No. 77-48-5) exhibits antimicrobial effects in water. It is used as a post-harvest intervention in the beef industry, and results from laboratory studies and commercial trials have shown a reduction in E. coli and Salmonella levels1 with HOBr from DBDMH. It can be used to control bacterial numbers on beef hides, carcasses, heads and organs. This chemistry is also used in the poultry processing industry. DBDMH is a stable white to off-white granular solid. In water, DBDMH undergoes a hydrolysis reaction to form two molecules of hypobromous acid (HOBr) and one molecule of dimethylhydantoin (DMH). During use, DBDMH is placed into a flow-through chemical feeder. The aqueous output of this feeder is mixed with a separate stream of water to dilute the HOBr to the desired level, and supply a constant stream of HOBr to the DBDMH application system. The water flow to the feeder and the water flow for dilution can be controlled to achieve the proper dilution to obtain the desired HOBr concentration. Hypobromous acid is the active antimicrobial agent in the water applied to the beef. The oxidizing action of hypobromous acid kills the bacteria.
    [Show full text]
  • Measurement Report: Indirect Evidence for the Controlling Influence of Acidity on the Speciation of Iodine in Atlantic Aerosols
    Atmos. Chem. Phys., 21, 13067–13076, 2021 https://doi.org/10.5194/acp-21-13067-2021 © Author(s) 2021. This work is distributed under the Creative Commons Attribution 4.0 License. Measurement report: Indirect evidence for the controlling influence of acidity on the speciation of iodine in Atlantic aerosols Alex R. Baker1 and Chan Yodle1,a 1Centre for Ocean and Atmospheric Sciences, School of Environmental Sciences, University of East Anglia, Norwich, NR4 7TJ, UK anow at: Department of Environmental Science, Faculty of Science and Technology, Chiang Mai Rajabhat University, Chiang Mai, 50300, Thailand Correspondence: Alex R. Baker ([email protected]) Received: 26 January 2021 – Discussion started: 26 April 2021 Revised: 22 July 2021 – Accepted: 10 August 2021 – Published: 2 September 2021 Abstract. The speciation of soluble iodine and major- 1 Introduction ion composition were determined in size-fractionated aerosols collected during the AMT21 cruise between Avon- mouth, UK, and Punta Arenas, Chile, in September– Iodine (I) plays a significant role in the destruction of ozone November 2011. The proportions of iodine species (iodide, (O3) in the atmosphere (Davis et al., 1996; Saiz-Lopez et iodate and soluble organic iodine (SOI)) varied markedly be- al., 2012), being responsible for ∼ 30 % of O3 loss in the tween size fractions and with the extent to which the samples marine boundary layer (MBL) (Prados-Roman et al., 2015). were influenced by pollutants. In general, fine mode aerosols Oceanic emission, principally of volatile I2 and hypoiodous (< 1 µm) contained higher proportions of both iodide and acid (HOI) formed through the reaction of O3 with iodide − SOI, while iodate was the dominant component of coarse (I ) at the sea surface (Carpenter et al., 2013), is the main (< 1 µm) aerosols.
    [Show full text]