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Carbon Kinetic Isotope Effect in the Oxidation of Methane by The
JOURNAL OF GEOPHYSICAL RESEARCH, VOL. 95, NO. D13, PAGES 22,455-22,462, DECEMBER 20, 1990 CarbonKinetic IsotopeEffect in the Oxidationof Methaneby the Hydroxyl Radical CttRISTOPHERA. CANTRELL,RICHARD E. SHE•, ANTHONY H. MCDANmL, JACK G. CALVERT, JAMESA. DAVIDSON,DAVID C. LOWEl, STANLEYC. TYLER,RALPH J. CICERONE2, AND JAMES P. GREENBERG AtmosphericKinetics and PhotochemistryGroup, AtmosphericChemistry Division, National Centerfor AtmosphericResearch, Boulder, Colorado The reactionof the hydroxylradical (HO) with the stablecafix)n isotopes of methanehas been studied as a functionof temperaturefrom 273 to 353 K. The measuredratio of the rate coefficientsfor reaction with•ZCHn relative to •3CH•(kn•/kn3) was 1.0054 (20.0009 at the95% confidence interval), independent of temperaturewithin the precisionof the measurement,over the rangestudied. The precisionof the present valueis muchimproved over that of previousstudies, and this resultprovides important constraints on the currentunderstanding of the cyclingof methanethrough the atmospherethrough the useof carbonisotope measurements. INTRODUCTION weightedaverage of the sourceratios must equal the atmospher- Methane (CH•) is an importanttrace gas in the atmosphere ic ratio, after correctionfor fractionationin any lossprocesses. [Wofsy,1976]. It is a key sink for the tropospherichydroxyl The primaryloss of CI-I4in the troposphereis the reactionwith radical. Methane contributesto greenhousewarming [Donner the hydroxylradical: and Ramanathan,1980]; its potentialwarming effects follow only CO2 and H20. Methaneis a primary sink for chlorine (R1) CHn + HO ---)CH3 + HzO atomsin the stratosphereand a majorsource of watervapor in the upper stratosphere. The concentrationof CI-I4 in the The rate coefficient for this reaction has been studied extensive- tropospherehas been increasing at a rateof approximately1% ly (seereview by Ravishankara[1988]), but dataindicating the per year, at leastover the pastdecade [Rasmussen and Khalil, effect of isotopesubstitution in methaneare scarce. -
Radical Approaches to Alangium and Mitragyna Alkaloids
Radical Approaches to Alangium and Mitragyna Alkaloids A Thesis Submitted for a PhD University of York Department of Chemistry 2010 Matthew James Palframan Abstract The work presented in this thesis has focused on the development of novel and concise syntheses of Alangium and Mitragyna alkaloids, and especial approaches towards (±)-protoemetinol (a), which is a key precursor of a range of Alangium alkaloids such as psychotrine (b) and deoxytubulosine (c). The approaches include the use of a key radical cyclisation to form the tri-cyclic core. O O O N N N O O O H H H H H H O N NH N Protoemetinol OH HO a Psychotrine Deoxytubulosine b c Chapter 1 gives a general overview of radical chemistry and it focuses on the application of radical intermolecular and intramolecular reactions in synthesis. Consideration is given to the mediator of radical reactions from the classic organotin reagents, to more recently developed alternative hydrides. An overview of previous synthetic approaches to a range of Alangium and Mitragyna alkaloids is then explored. Chapter 2 follows on from previous work within our group, involving the use of phosphorus hydride radical addition reactions, to alkenes or dienes, followed by a subsequent Horner-Wadsworth-Emmons reaction. It was expected that the tri-cyclic core of the Alangium alkaloids could be prepared by cyclisation of a 1,7-diene, using a phosphorus hydride to afford the phosphonate or phosphonothioate, however this approach was unsuccessful and it highlighted some limitations of the methodology. Chapter 3 explores the radical and ionic chemistry of a range of silanes. -
Synthesis and Kinetics of Novel Ionic Liquid Soluble Hydrogen Atom Transfer Reagents
Synthesis and kinetics of novel ionic liquid soluble hydrogen atom transfer reagents Thomas William Garrard Submitted in total fulfilment of the requirements of the degree Doctor of Philosophy June 2018 School of Chemistry The University of Melbourne Produced on archival quality paper ORCID: 0000-0002-2987-0937 Abstract The use of radical methodologies has been greatly developed in the last 50 years, and in an effort to continue this progress, the reactivity of radical reactions in greener alternative solvents is desired. The work herein describes the synthesis of novel hydrogen atom transfer reagents for use in radical chemistry, along with a comparison of rate constants and Arrhenius parameters. Two tertiary thiol-based hydrogen atom transfer reagents, 3-(6-mercapto-6-methylheptyl)-1,2- dimethyl-3H-imidazolium tetrafluoroborate and 2-methyl-7-(2-methylimidazol-1-yl)heptane-2-thiol, have been synthesised. These are modelled on traditional thiol reagents, with a six-carbon chain with an imidazole ring on one end and tertiary thiol on the other. 3-(6-mercapto-6-methylheptyl)- 1,2-dimethyl-3H-imidazolium tetrafluoroborate comprises of a charged imidazolium ring, while 2- methyl-7-(2-methylimidazol-1-yl)heptane-2-thiol has an uncharged imidazole ring in order to probe the impact of salt formation on radical kinetics. The key step in the synthesis was addition of thioacetic acid across an alkene to generate a tertiary thioester, before deprotection with either LiAlH4 or aqueous NH3. Arrhenius plots were generated to give information on rate constants for H-atom transfer to a primary alkyl radical, the 5-hexenyl radical, in ethylmethylimidazolium bis(trifluoromethane)sulfonimide. -
O/C -O-O-( X, Generally Carried out at a Temperature in the Range of 20 and (B) Mineral Acid Salts of These Compounds
3,256,288 United States Patent Office Patented June 14, 1966 W 2 -Cl, -Br or -SONH2, with an appropriate imino ether 3,256,288 hydrochloride having the formula -SUBSTITUTED AMNOALKYL-2-ARYLOXY METHYLEBENZRADAZOLE COMPOUNDS E Clarence L. Moyle, Care, and Diomed M. Cher, Mid land, Mich., assignors to The Dow Chemical Company, Midland, Mich., a corporation of Delaware W (III) No Drawing. Fied May 24, 1962, Ser. No. 197,285 wherein in this and succeeding formulas, E is -H, -R, 9 Claims. (C. 260-294.7) -CI, -Br, -OH, -OR or -CONH2 and R' is a lower alkyl group, to produce the desired benzimidazole product This invention is directed to benzimidazole compounds, O and R'OH, NH3 and HCl by-products. The gaseous NH particularly (a) N-substituted benzimidazole compounds and HCl generally evolve from the reaction mixture al having the formula though some of the HC1 may react with NH and remain in the reaction mixture as ammonium chloride salt or may react with the basic benzimidazole product and remain 5 as the hydrochloride salt thereof. / N Y In carrying out the preparation, substantially equimolar proportions of the reactants are employed although either reactant may be employed in excess. The reaction is O/C -o-o-( x, generally carried out at a temperature in the range of 20 and (b) mineral acid salts of these compounds. In this from 60 to 82° C. for a period of from about 20 to 72 and succeeding formulas-NR'R'' is di(lower-alkyl)ami hours. It is preferred that an alcoholic solvent be em no, piperidino, morpholino or pyrrolidino; X is -H, ployed in this process. -
The Distribution of the Hydroxyl Radical in the Troposphere Jack
The Distribution of the Hydroxyl Radical in the Troposphere By Jack Fishman Paul J. Crutzen Department of Atmospheric Science Colorado State University Fort Collins, Colorado THE DISTRIBUTION OF THE HYDROXYL RADICAL IN THE TROPOSPHERE by Jack Fishman and Paul J. Crutzen Preparation of this report has been financially supported by Environmental Protection Agency Grant No. R80492l-0l Department of Atmospheric Science Colorado State University Fort Collins, Colorado January, 1978 Atmospheric Science Paper No. 284 Abstract A quasi-steady state photochemical numerical model is developed to calculate a two-dimensional distribution of the hydroxyl (OH) radical in the troposphere. The diurnally, seasonally averaged globaJ 5 3 value of OH derived by this model is 3 x 10 cm- which is several times lower than the number computed previously by other models, but is in good agreement with the value inferred from the analysis of the tropospheric distribution of methyl chloroform. Likewise, the effects of the computed OH distribution on the tropospheric budgets of ozone and carbon monoxide are not inconsistent with this lower computed value. One important result of this research is the detailed analysis of the distribution of tropospheric ozone in the Southern Hemisphere. Our work shows that there is a considerable difference in the tropospheric ozone patterns of the two hemispheres and that through the analysis of the likely photochemistry occurring in the troposphere, a significant source of tropospheric ozone may exist in the Northern Hemisphere due to carbon monoxide oxidation. Future research efforts will be devoted to the meteorological dynamics of the two hemispheres to try to distinguish if these physical processes are similarly able to explain the interhemispheric differences in tropospheric ozone. -
Investigation of Evaporation Characteristics of Polonium and Its Lighter Homologues Selenium and Tellurium from Liquid Pb-Bi-Eutecticum
EUROPEAN ORGANIZATION FOR NUCLEAR RESEARCH CERN-PH-EP/2004-061 18 November 2004 Investigation of evaporation characteristics of polonium and its lighter homologues selenium and tellurium from liquid Pb-Bi-eutecticum J. Neuhausen*1, U. Köster2 and B. Eichler1 1Laboratory for Radio- and Environmental Chemistry; Paul Scherrer Institute, CH-5232 Villigen PSI, Switzerland 2CERN, ISOLDE, CH-1211 Genève 23, Switzerland Abstract The evaporation behaviour of polonium and its lighter homologues selenium and tellurium dissolved in liquid Pb-Bi-eutecticum (LBE) has been studied at various temperatures in the range from 482 K up to 1330 K under Ar/H2 and Ar/H2O-atmospheres using γ-ray spectroscopy. Polonium release in the temperature range of interest for technical applications is slow. Within short term (1h) experiments measurable amounts of polonium are evaporated only at temperatures above 973 K. Long term experiments reveal that a slow evaporation of polonium occurs at temperatures around 873 K resulting in a fractional polonium loss of the melt around 1% per day. Evaporation rates of selenium and tellurium are smaller than those of polonium. The presence of H2O does not enhance the evaporation within the error limits of our experiments. The thermodynamics and possible reaction pathways involved in polonium release from LBE are discussed. (Submitted to Radiochimica Acta) * Author for correspondence (E-mail: [email protected]). 2 1. Introduction Liquid Lead-Bismuth eutecticum (LBE) is proposed to be used as target material in spallation neutron sources [1] as well as in Accelerator Driven Systems (ADS) for the transmutation of long-lived nuclear waste [2]. In these systems polonium is formed as a product of (p,xn) and (n,γ)-reactions according to the following processes: 209Bi ⎯⎯(p,xn)⎯→208,209Po (1) γ β − 209Bi ⎯⎯(n,⎯)→210Bi ⎯⎯→⎯ 210Po (2) Within 1 year of operation employing a proton beam current of 1 mA around 2 g of polonium are produced in this manner [3]. -
Radical Cyclization in Heterocycle Synthesis. 12.1) Sulfanyl Radical
February 2001 Chem. Pharm. Bull. 49(2) 213—224 (2001) 213 Radical Cyclization in Heterocycle Synthesis. 12.1) Sulfanyl Radical Addition–Addition–Cyclization (SRAAC) of Unbranched Diynes and Its Application to the Synthesis of A-Ring Fragment of 1a,25-Dihydroxyvitamin D3 Okiko MIYATA, Emi NAKAJIMA, and Takeaki NAITO* Kobe Pharmaceutical University, Motoyamakita, Higashinada, Kobe 658–8558, Japan. Received September 25, 2000; accepted October 24, 2000 Sulfanyl radical addition–addition–cyclization (SRAAC) of unbranched diynes proceeded smoothly to give cyclized exo-olefins, while the sulfanyl radical addition–cyclization–addition (SRACA) of diynes having a quater- nary carbon gave cyclized endo-olefins. This method was successfully applied to the synthesis of A-ring fragment of 1a,25-dihydroxyvitamin D3. Key words sulfanyl radical; addition–addition–cyclization; diyne; alkylidenecyclopentane; alkylidenecyclohexane; vitamin D Radical cyclization is a useful method for the preparation ther a quaternary carbon or a heteroatom, sulfanyl radical ad- of various cyclic compounds.1) Recently, this method in dition–cyclization–addition (SRACA) occurred to give endo- 5 5 which carbon centered radical species are generated by the olefin 3. In the case of longer carbon chain, 1 (n 2, X CH2, addition reaction of a radical to a multiple bond has drawn C(COOMe)2) gave exo-olefin 2 as the major product, while 1 5 5 the attention of synthetic chemists because of its several ad- (n 2, X NSO2Ar) gave a complex mixture. Synthetic util- vantages, such as readily available starting substrate and for- ity of newly found SRAAC has been proved by a novel syn- mation of functionalized products. -
[(4-Chlorophenyl) Sulfanyl] Ethoxy- 3-Methoxy-5-[5-(3,4,5-Trimethoxyphenyl)-2-Furyl]Benzonitrile
Available online a t www.derpharmachemica.com Scholars Research Library Der Pharma Chemica, 2015, 7(3):242-247 (http://derpharmachemica.com/archive.html) ISSN 0975-413X CODEN (USA): PCHHAX Synthesis and antibacterial activity of 2-2-[(4-chlorophenyl) sulfanyl] ethoxy- 3-methoxy-5-[5-(3,4,5-trimethoxyphenyl)-2-furyl]benzonitrile P. Veerabhadra Swamy*a,b , K. B. Chandrasekhar c and Pullaiah China Kambhampati a aLaxai Avanti Life Sciences, Lab#9, ICICI Knowledge park, Shameerpet, Turkapally Village, Hyderabad bDepartment of Chemistry, Jawaharlal Nehru Technological University, Hyderabad, Hyderabad, Telengana, India cDepartment of Chemistry, Jawaharlal Nehru Technological University, Anantapur, Anantapuramu, A.P., India _____________________________________________________________________________________________ ABSTRACT The present paper describes the synthesis and of (2-(4-chlorophenylthio)ethoxy)-3-methoxy-5-(5-(3,4,5- trimethoxyphenyl)furan-2-yl)benzonitrile from commercially available vanillin and 3,4,5-trimethoxy acetophenone as starting materials utilizing green reagents and solvents. The antibacterial test results indicated that the title compound displayed excellent activity against both Gram-positive bacteria (Staphylococcus aureus and Bacillus cereus) and Gram-negative bacteria: (Escherichia Coli and Pseudomonas aeruginosa). Keywords: Antibacterial activity, Furan, 3,4,5-trimethoxy acetophenone, vanillin, synthesis _____________________________________________________________________________________________ INTRODUCTION Furan derivatives -
Investigation on the Polonium Problem in Lead-Bismuth Coolant for Nuclear Reactors
Proceedings of the Korean Nuclear Society Spring Meeting Gyeongju, Korea, May 2003 Investigation on the Polonium Problem in Lead-Bismuth Coolant for Nuclear Reactors Sung Il Kim, Kun Jai Lee Korea Advanced Institute of Science and Technology 373-1, Kusong-dong, Yusong-gu, Daejon, 305-701, Korea Abstract By using lead-bismuth eutectic as a coolant for nuclear reactors and liquid metal targets of accelerator driven system attention is paid to high hazard of alpha-active polonium generated in lead-bismuth eutectic under operation of these installation. Therefore rather high technology culture and special means of radiation safety ensuring are required in handling with radioactive lead-bismuth eutectic. The results of investigation are briefly described on lead-bismuth eutectic purification from polonium using alkaline extraction. 1. Introduction Very long-lived core, lead-bismuth cooled, fast reactors have continued to be investigated in Japan, and in the United States at the University of California at Berkeley. A lead-bismuth cooled, accelerator-driven, sub-critical actinide-burner (labeled ATW) has been proposed by the Los Alamos National Laboratory (LANL) for burning the actinides and long-life fission products from spent light water reactor fuel. In Korea, KAERI is setting up a long-term research program called HYPER (Hybrid Power Extraction Reactor) and also SNU (Seoul National University) proposed a new transmutation concept designated as PEACER (Proliferation-resistant Environmental- friendly Accident-tolerant Continuable and Economical Reactor). Both of them include the concept of pyroprocess-based partitioning system and lead-bismuth cooled transmutation reactor. So we needed a study on the problem of coolant activation in lead-bismuth coolant reactor. -
United States Patent (19) 11) Patent Number: 4,731,479 Bod Et Al
United States Patent (19) 11) Patent Number: 4,731,479 Bod et al. 45 Date of Patent: Mar. 15, 1988 (54) N-SULFAMYL-3-HALOPROPIONAMIDINES Attorney, Agent, or Firm-Karl F. Ross; Herbert Dubno; 75 Inventors: Péter Bod, Gyömrö; Kálmán Jonathan Myers Harsányi, Budapest; Eva Againée (57) ABSTRACT Csongor, Budapest; Erik Bogsch, Budapest; Eva Fekecs, Budapest; The invention relates to new propionamidine deriva Ferenc Trischler, Budapest; György tives of formula (I) Domány, Budapest; István Szabadkai, Budapest; Béla Hegedis, Budapest, NH2HX (I) all of Hungary x^-sn-so- NH2 73) Assignee: Richter Gedeon Vegyeszeti Gyar Rt., Budapest, Hungary wherein (21) Appl. No.: 905,833 X is halogen, and to a process for their preparation. According to the 22 Filed: Sep. 10, 1986 invention compounds of the formula (I) are prepared by 30 Foreign Application Priority Data reacting a 3-halopropionitrile of the formula (III) Sep. 11, 1985 HU) Hungary .............................. 3423/85 51) Int. Cl." ............................................ CO7C 143/72 (III) 52 U.S.C. ...................................................... 564/79 58 Field of Search .......................................... 564/79 wherein (56) References Cited X is as defined above, U.S. PATENT DOCUMENTS with sulfamide of the formula (II) 3,121,084 2/1964 Winberg................................ 564/79 (II) FOREIGN PATENT DOCUMENTS 905408 12/1986 Belgium. NH-i-NH. O OTHER PUBLICATIONS Wagner et al, "Synthetic Organic Chemistry', (1953), in the presence of a hydrogen halide. p. 635. Compounds of the formula (I) are useful intermediates Richter, "Text Book of Organic Chemistry,” (1952), p. 216. in the preparation of famotidine. Primary Examiner-Anton H. Sutto 1 Claim, No Drawings 4,731,479 1. -
Standard Thermodynamic Properties of Chemical
STANDARD THERMODYNAMIC PROPERTIES OF CHEMICAL SUBSTANCES ∆ ° –1 ∆ ° –1 ° –1 –1 –1 –1 Molecular fH /kJ mol fG /kJ mol S /J mol K Cp/J mol K formula Name Crys. Liq. Gas Crys. Liq. Gas Crys. Liq. Gas Crys. Liq. Gas Ac Actinium 0.0 406.0 366.0 56.5 188.1 27.2 20.8 Ag Silver 0.0 284.9 246.0 42.6 173.0 25.4 20.8 AgBr Silver(I) bromide -100.4 -96.9 107.1 52.4 AgBrO3 Silver(I) bromate -10.5 71.3 151.9 AgCl Silver(I) chloride -127.0 -109.8 96.3 50.8 AgClO3 Silver(I) chlorate -30.3 64.5 142.0 AgClO4 Silver(I) perchlorate -31.1 AgF Silver(I) fluoride -204.6 AgF2 Silver(II) fluoride -360.0 AgI Silver(I) iodide -61.8 -66.2 115.5 56.8 AgIO3 Silver(I) iodate -171.1 -93.7 149.4 102.9 AgNO3 Silver(I) nitrate -124.4 -33.4 140.9 93.1 Ag2 Disilver 410.0 358.8 257.1 37.0 Ag2CrO4 Silver(I) chromate -731.7 -641.8 217.6 142.3 Ag2O Silver(I) oxide -31.1 -11.2 121.3 65.9 Ag2O2 Silver(II) oxide -24.3 27.6 117.0 88.0 Ag2O3 Silver(III) oxide 33.9 121.4 100.0 Ag2O4S Silver(I) sulfate -715.9 -618.4 200.4 131.4 Ag2S Silver(I) sulfide (argentite) -32.6 -40.7 144.0 76.5 Al Aluminum 0.0 330.0 289.4 28.3 164.6 24.4 21.4 AlB3H12 Aluminum borohydride -16.3 13.0 145.0 147.0 289.1 379.2 194.6 AlBr Aluminum monobromide -4.0 -42.0 239.5 35.6 AlBr3 Aluminum tribromide -527.2 -425.1 180.2 100.6 AlCl Aluminum monochloride -47.7 -74.1 228.1 35.0 AlCl2 Aluminum dichloride -331.0 AlCl3 Aluminum trichloride -704.2 -583.2 -628.8 109.3 91.1 AlF Aluminum monofluoride -258.2 -283.7 215.0 31.9 AlF3 Aluminum trifluoride -1510.4 -1204.6 -1431.1 -1188.2 66.5 277.1 75.1 62.6 AlF4Na Sodium tetrafluoroaluminate -
Reactivity of the Solvated Electron, the Hydroxyl Radical and Its Precursor in Deuterated Water Studied by Picosecond Pulse Radiolysis Furong Wang
Reactivity of the Solvated Electron, the Hydroxyl Radical and its Precursor in Deuterated Water Studied by Picosecond Pulse Radiolysis Furong Wang To cite this version: Furong Wang. Reactivity of the Solvated Electron, the Hydroxyl Radical and its Precursor in Deuter- ated Water Studied by Picosecond Pulse Radiolysis. Theoretical and/or physical chemistry. Université Paris Saclay (COmUE), 2018. English. NNT : 2018SACLS399. tel-02057515 HAL Id: tel-02057515 https://tel.archives-ouvertes.fr/tel-02057515 Submitted on 5 Mar 2019 HAL is a multi-disciplinary open access L’archive ouverte pluridisciplinaire HAL, est archive for the deposit and dissemination of sci- destinée au dépôt et à la diffusion de documents entific research documents, whether they are pub- scientifiques de niveau recherche, publiés ou non, lished or not. The documents may come from émanant des établissements d’enseignement et de teaching and research institutions in France or recherche français ou étrangers, des laboratoires abroad, or from public or private research centers. publics ou privés. Reactivity of the Solvated Electron, the Hydroxyl Radical and its Precursor in Deuterated Water 2018SACLS399 : Studied by Picosecond Pulse NNT Radiolysis Thèse de doctorat de l'Université Paris-Saclay préparée à l'Université Paris-Sud École doctorale n°571 : sciences chimiques : molécules, matériaux instrumentation et biosystèmes (2MIB) Spécialité de doctorat : Chimie Thèse présentée et soutenue, le 22 Octobre, 2018, par Mme Furong WANG Composition du Jury : Mme Isabelle Lampre Professeur, Université Paris-Sud (– LCP) Présidente M. Jean-Marc Jung Professeur, Université de Strasbourg (– IPHC) Rapporteur M. Philippe Moisy Directeur de recherche, CEA Marcoule Rapporteur Mme Sophie Le Caer Directrice de recherche, CEA (– LIONS) Examinateur M.