Photooxidation of Cyclohexene in the Presence of SO2: SOA Yield and Chemical Composition

Total Page:16

File Type:pdf, Size:1020Kb

Photooxidation of Cyclohexene in the Presence of SO2: SOA Yield and Chemical Composition Atmos. Chem. Phys., 17, 13329–13343, 2017 https://doi.org/10.5194/acp-17-13329-2017 © Author(s) 2017. This work is distributed under the Creative Commons Attribution 3.0 License. Photooxidation of cyclohexene in the presence of SO2: SOA yield and chemical composition Shijie Liu1,2,3, Long Jia2, Yongfu Xu2, Narcisse T. Tsona1, Shuangshuang Ge2, and Lin Du3,1,2 1Environment Research Institute, Shandong University, Jinan, 250100, China 2State Key Laboratory of Atmospheric Boundary Layer Physics and Atmospheric Chemistry, Institute of Atmospheric Physics, Chinese Academy of Sciences, Beijing, 100029, China 3Shenzhen Research Institute, Shandong University, Shenzhen, 518057, China Correspondence to: Lin Du ([email protected]) and Yongfu Xu ([email protected]) Received: 12 January 2017 – Discussion started: 15 February 2017 Revised: 28 September 2017 – Accepted: 8 October 2017 – Published: 9 November 2017 Abstract. Secondary organic aerosol (SOA) formation from 1 Introduction a cyclohexene = NOx system with various SO2 concentra- tions under UV light was investigated to study the effects Alkenes are widely emitted from biogenic and anthropogenic of cyclic alkenes on the atmospheric environment in polluted sources (Kesselmeier et al., 2002; Chin and Batterman, urban areas. A clear decrease at first and then an increase 2012), and their gas-phase oxidation reactions with OH, in the SOA yield was found with increasing SO2 concen- NO3, or O3 are among the most important processes in the trations. The lowest SOA yield was obtained when the ini- atmosphere (Atkinson, 1997; Stewart et al., 2013; Paulson tial SO2 concentration was in the range of 30–40 ppb, while et al., 1999). Reactions of ozone with alkenes are an impor- higher SOA yield compared to that without SO2 could not tant source of free radicals in the lower atmosphere and thus be obtained until the initial SO2 concentration was higher highly influence the oxidative capacity of the atmosphere than 85 ppb. The decreasing SOA yield might be due to the (Paulson and Orlando, 1996). Some products of these reac- fact that the promoting effect of acid-catalysed reactions on tions have sufficiently low vapour pressure, allowing them to SOA formation was less important than the inhibiting effect condense with other gaseous species, and contribute to the of decreasing OH concentration at low initial SO2 concentra- secondary organic aerosol (SOA) mass (Sarwar and Corsi, tions, caused by the competition reactions of OH with SO2 2007; Sakamoto et al., 2013; Nah et al., 2016; Kroll and Se- and cyclohexene. The competitive reaction was an impor- infeld, 2008; Hallquist et al., 2009). SOA formation from the tant factor for SOA yield and it should not be neglected in oxidation of VOCs has been receiving significant attention photooxidation reactions. The composition of organic com- in recent years due to its large implication in the formation pounds in SOA was measured using several complemen- of atmospheric fine particulate matter (Jimenez et al., 2009). tary techniques including Fourier transform infrared (FTIR) SOA has significant impacts on human health (Pope III and spectroscopy, ion chromatography (IC), and Exactive Plus Dockery, 2006), air quality (Kanakidou et al., 2005; Jaoui et Orbitrap mass spectrometer equipped with electrospray in- al., 2012; McFiggans et al., 2006), and global climate change terface (ESI). We present new evidence that organosulfates (Hansen and Sato, 2001; Adams et al., 2001; Pokhrel et al., were produced from the photooxidation of cyclohexene in 2016). the presence of SO2. Although cyclic alkenes widely exist in the atmosphere, their gas-phase oxidation has received less attention than that of linear or branched alkenes (Sipilä et al., 2014). Cyclohexene is an important industrial chemical (Sun et al., 2013) and is also widespread in urban areas (Gros- jean et al., 1978). Cyclohexene has been extensively studied as a monoterpene surrogate for inferring oxidation mecha- Published by Copernicus Publications on behalf of the European Geosciences Union. 13330 S. Liu et al.: Photooxidation of cyclohexene in the presence of SO2 nisms and aerosol formation characteristics, because it has 2008; Hatch et al., 2011). Despite the well-recognized pres- the basic structural unit in abundant biogenic monoterpenes ence of organosulfates in SOA, their formation and trans- and sesquiterpenes (Carlsson et al., 2012; Keywood et al., formation processes can be complex and varied, depending 2004b). The rate constants for gas-phase reactions of cyclo- on the nature of the original organic compound involved. hexene with OH, O3, and NO3 were measured at room tem- Extensive studies on their formation have been performed perature to be (6.4 ± 0.1)× 10−11, (8.1 ± 1.8)× 10−17, and and several mechanisms based on a variety of reactions (5.4 ± 0.2)× 10−13 cm3 molecule−1 s−1, respectively (Stew- have been proposed. Using nuclear resonance techniques, art et al., 2013; Aschmann et al., 2012), and a correlation isoprene-derived epoxides formed during isoprene photoox- between the logarithm of the rate constants and the molecu- idation reactions were found to be important intermediates lar orbital energies for simple cyclic alkenes was observed. for organonitrate and organosulfate formation via potential The effect of pressure and that of the presence of SO2 on SOA reactions (Darer et al., 2011; Hu et al., 2011). The au- the formation of stable gas-phase products and SOA from thors further found that organonitrates could easily be trans- the ozonolysis of cyclohexene were investigated (Carlsson formed to organosulfates during hydrolysis in the presence et al., 2012). It was found that the collisional stabilization of sulfate. Some studies also showed that 2-methyl-3-buten- of initial clusters was an important aspect for SOA forma- 2-ol (MBO), due to its emissions that are larger than isoprene tion processes involving sulfuric acid (H2SO4/ and organic in some regions (Baker et al., 1999), is an important precur- compounds. The effect of the structure of the hydrocarbon sor for organosulfates and SOA in the atmosphere through parent molecule on SOA formation was investigated for a se- its reactions with OH under NO and aerosol acidity condi- ries of cyclic alkenes and related compounds (Keywood et tions and from acid-catalysed reactive uptake of MBO-based al., 2004b), and the SOA yield was found to be a function of epoxides formed during MBO photooxidation (Mael et al., the number of carbons present in the cyclic alkenes ring. The 2015; Zhang et al., 2012, 2014). Organosulfate formation relative SOA yields from ozonolysis of cyclic alkenes can be was also found from oxidation of hydroxyhydroperoxides quantitatively predicted from properties of the parent hydro- (Riva et al., 2016) and from heterogeneous reactions of SO2 carbons, like the presence of a methyl group and an exocyclic with selected long-chain alkenes and unsaturated fatty acids double bond. (Passananti et al., 2016). SO2, one of the most important inorganic pollutants in ur- Reactions with sulfates or H2SO4 were the main for- ban areas, plays an important role in SOA formation (Wang mation processes of organosulfates. Qualitative analyses of et al., 2005; Lonsdale et al., 2012; Liu et al., 2016). Seasonal organosulfates in SOA have been gaining more attention and variations of SO2 concentrations were found to be consis- development in recent years (Lin et al., 2012; Shalamzari tent with seasonal variations of PM2:5 concentration (Cheng et al., 2013; Staudt et al., 2014). Riva et al. (2015) investi- et al., 2015). Smog chamber simulations have indicated that gated the formation of organosulfates from photooxidation of SO2 could enhance the formation of SOA from the oxidation polycyclic aromatic hydrocarbons and found that, in the pres- of VOCs under acidic conditions by increasing aerosol acid- ence of sulfate aerosol, this photooxidation was a hitherto un- ity and ammonium sulfate aerosol formation (Edney et al., recognized source of anthropogenic secondary organosulfur 2005; Liu et al., 2016; Attwood et al., 2014). Anthropogenic compounds (Riva et al., 2015). A more complete structural SO2 emissions can impact new particle formation, and SOA characterization of polar organosulfates that originate from composition (Lonsdale et al., 2012). isoprene SOA was performed (Shalamzari et al., 2013), and Although the existence of organosulfates in ambient an organosulfate related to methyl vinyl ketone and minor aerosols was first observed in 2005 (Romero and Oehme, polar organosulfates related to croton aldehyde were identi- 2005), proper identification of these aerosols was done 2 fied. However, there have been no reports on the yield and years later. In a series of laboratory chamber studies, it was chemical composition of SOA obtained from photooxidation shown that organosulfates present in ambient aerosols col- of cyclohexene in the presence of SO2. lected from various locations mostly originate from acid- In the present work, we investigated the yields and chemi- catalysed reactions of SOA formed from photooxidation of cal composition of SOA during cyclohexene photooxidation α-pinene and isoprene (Surratt et al., 2007). Recently, dif- under different SO2 concentrations conditions. A better un- ferent kinds of organosulfates have been observed in SOA derstanding of the magnitude and chemical composition of around the world, and organosulfates have been identified SOA from different SO2 concentrations will contribute to a as a group of compounds that have an important contribu- more accurate SOA prediction from anthropogenic sources tion to the total amount of SOA in the atmosphere (Sur- and provide valuable information related to air pollution in ratt et al., 2008; Froyd et al., 2010; Kristensen and Glasius, urban environments. 2011; Tolocka and Turpin, 2012; Wang et al., 2016). Labo- ratory chamber studies showed that OH = NOx = O3-initiated reactions of BVOCs, such as isoprene, α-pinene, β-pinene, and limonene with sulfates or sulfuric acid are the main processes for organosulfate formation (Surratt et al., 2007, Atmos. Chem. Phys., 17, 13329–13343, 2017 www.atmos-chem-phys.net/17/13329/2017/ S.
Recommended publications
  • Cyclohexane Oxidation Continues to Be a Challenge Ulf Schuchardt A,∗, Dilson Cardoso B, Ricardo Sercheli C, Ricardo Pereira A, Rosenira S
    Applied Catalysis A: General 211 (2001) 1–17 Review Cyclohexane oxidation continues to be a challenge Ulf Schuchardt a,∗, Dilson Cardoso b, Ricardo Sercheli c, Ricardo Pereira a, Rosenira S. da Cruz d, Mário C. Guerreiro e, Dalmo Mandelli f , Estevam V. Spinacé g, Emerson L. Pires a a Instituto de Qu´ımica, Universidade Estadual de Campinas, P.O. Box 6154, 13083-970 Campinas, SP, Brazil b Depto de Eng. Qu´ımica, Universidade Federal de São Carlos, 13565-905 São Carlos, SP, Brazil c College of Chemistry, University of California, Berkeley, CA 94720, USA d Depto Ciências Exatas e Tecnológicas, Universidade Estadual de Santa Cruz, 45650-000 Ilhéus, BA, Brazil e Universidade Federal de Lavras, Lavras, MG, Brazil f Instituto de Ciências Biológicas e Qu´ımicas, PUC-Campinas, 13020-904 Campinas, SP, Brazil g Sup. Caracterização Qu´ımica, IPEN, 05508-900 São Paulo, SP, Brazil Received 3 October 2000; received in revised form 21 December 2000; accepted 28 December 2000 Abstract Many efforts have been made to develop new catalysts to oxidize cyclohexane under mild conditions. Herein, we review the most interesting systems for this process with different oxidants such as hydrogen peroxide, tert-butyl hydroperoxide and molecular oxygen. Using H2O2, Na-GeX has been shown to be a most stable and active catalyst. Mesoporous TS-1 and Ti-MCM-41 are also stable, but the use of other metals such as Cr, V, Fe and Mo leads to leaching of the metal. Homogeneous systems based on binuclear manganese(IV) complexes have also been shown to be interesting. When t-BuOOH is used, the active systems are those phthalocyanines based on Ru, Co and Cu and polyoxometalates of dinuclear ruthenium and palladium.
    [Show full text]
  • Cycloalkanes, Cycloalkenes, and Cycloalkynes
    CYCLOALKANES, CYCLOALKENES, AND CYCLOALKYNES any important hydrocarbons, known as cycloalkanes, contain rings of carbon atoms linked together by single bonds. The simple cycloalkanes of formula (CH,), make up a particularly important homologous series in which the chemical properties change in a much more dramatic way with increasing n than do those of the acyclic hydrocarbons CH,(CH,),,-,H. The cyclo- alkanes with small rings (n = 3-6) are of special interest in exhibiting chemical properties intermediate between those of alkanes and alkenes. In this chapter we will show how this behavior can be explained in terms of angle strain and steric hindrance, concepts that have been introduced previously and will be used with increasing frequency as we proceed further. We also discuss the conformations of cycloalkanes, especially cyclo- hexane, in detail because of their importance to the chemistry of many kinds of naturally occurring organic compounds. Some attention also will be paid to polycyclic compounds, substances with more than one ring, and to cyclo- alkenes and cycloalkynes. 12-1 NOMENCLATURE AND PHYSICAL PROPERTIES OF CYCLOALKANES The IUPAC system for naming cycloalkanes and cycloalkenes was presented in some detail in Sections 3-2 and 3-3, and you may wish to review that ma- terial before proceeding further. Additional procedures are required for naming 446 12 Cycloalkanes, Cycloalkenes, and Cycloalkynes Table 12-1 Physical Properties of Alkanes and Cycloalkanes Density, Compounds Bp, "C Mp, "C diO,g ml-' propane cyclopropane butane cyclobutane pentane cyclopentane hexane cyclohexane heptane cycloheptane octane cyclooctane nonane cyclononane "At -40". bUnder pressure. polycyclic compounds, which have rings with common carbons, and these will be discussed later in this chapter.
    [Show full text]
  • Chem 267. Cyclohexene. (Revised 7/10). in This Experiment You Will
    Chem 267. Cyclohexene. (revised 7/10). In this experiment you will synthesize cyclohexene and purify it by distillation. You will check the purity and identity of the product by gas chromatography (GC) and infrared spectroscopy (IR). You will also do some simple chemical tests which distinguish alkenes from alkanes. Review the chapter on distillation and your notes from the distillation experiment. The "Things to Watch Out For in Distillations" listed for the distillation experiment are common to this distillation as well. As always, use care when inserting the thermometer into the thermometer adaptor. Hold the thermometer close to the adaptor and push and twist gently. Breakage could result in a serious injury. Check for frayed connectors and cracked flasks. Cyclohexene has a disagreeable odor, characteristic of volatile alkenes. Allow the apparatus to cool before disassembling it in the hood, and dispose of the wastes in the hood in the PROPER CONTAINERS (see below). Rinse the apparatus with a LITTLE acetone and dispose of that in the Nonhalogenated Liquid Waste container. CAUTION: cyclohexene is very flammable. Handle phosphoric acid with care. It is corrosive to tissue. If your skin comes into contact with phosphoric acid, wash the contaminated area immediately with water, then soap and water. Clean up spills immediately using the sodium bicarbonate in the hood. Do the Prelab Exercise on p. 334 (a model of a flow sheet is on p. 142). This is something to do for all synthesis experiments. Also always prepare a table of reactants and products such as that shown in the handout, “Sample Notebook and Report”.
    [Show full text]
  • Classification Tests for Hydrocarbons Using Solubility, Ignition, Nitration, Baeyer’S Test, Bromine Test and Basic Oxidation Test
    CLASSIFICATION TESTS FOR HYDROCARBONS USING SOLUBILITY, IGNITION, NITRATION, BAEYER’S TEST, BROMINE TEST AND BASIC OXIDATION TEST Jasher Christian Boado, Alyanna Cacas, Phoebe Calimag, Caryl Angelica Chin, Haidee Cosilet, John Francis Creencia Group 2, 2BMT, Faculty of Pharmacy, University of Santo Tomas ABSTRACT Hydrocarbons are classified as saturated, actively unsaturated, aromatic or an arene based on various classification tests involving test for solubility in concentrated H2SO4, ignition, active unsaturation using Baeyer’s test and Bromine test, aromaticity using nitration test, and basic oxidation test. This experiment aims to differentiate the intrinsic physical and the chemical properties of hydrocarbons, and to determine if it is saturated, actively unsaturated, aromatic or an arene. The sample compounds hexane, heptane, cyclohexane, cyclohexene, benzene and toluene were analyzed for their physical state in room temperature, color, and odor. Using solubility test, a drop of a sample was added cautiously into 1ml of concentrated H2SO4. Using the Baeyer’s Test and/or Bromine test in which 2 drops of 2% KmnO4 solution and 10 drops of 0.5% Br2 in CCl4 reagent, respectively, was added into 5 drops of a sample in a dry test tube, was shaken vigourously until the reagent is decolorized compared with water. Using Nitration test, 8 drops of nitrating mixture was added into 5 drops of a sample in a dry test tube, was observed for the formation of a yellow oily layer or droplet and was diluted with 20 drops of water. Using Basic Oxidation test, 8 drops of 2% KmnO4 solution and 3 drops of 10% NaOH solution was added into 4 drops of a sample in a dry test tube and was heated in a water bath for 2 minutes.
    [Show full text]
  • Addition Reactions and Photoisomerization of Cis,Trans-1,5-Cyclodecadiene
    Louisiana State University LSU Digital Commons LSU Historical Dissertations and Theses Graduate School 1970 Addition Reactions and Photoisomerization of Cis,trans-1,5-Cyclodecadiene. Hsin-hsiong Hsieh Louisiana State University and Agricultural & Mechanical College Follow this and additional works at: https://digitalcommons.lsu.edu/gradschool_disstheses Recommended Citation Hsieh, Hsin-hsiong, "Addition Reactions and Photoisomerization of Cis,trans-1,5-Cyclodecadiene." (1970). LSU Historical Dissertations and Theses. 1859. https://digitalcommons.lsu.edu/gradschool_disstheses/1859 This Dissertation is brought to you for free and open access by the Graduate School at LSU Digital Commons. It has been accepted for inclusion in LSU Historical Dissertations and Theses by an authorized administrator of LSU Digital Commons. For more information, please contact [email protected]. 71-6579 HSIEH, Hsin-Hsiong, 1936- ADDITION REACTIONS AND PHOTOISOMERIZATION OF CIS,TRANS-1,5-CYCLODECADIENE. The Louisiana State University and Agricultural and Mechanical College, Ph.D., 1970 Chemistry, organic University Microfilms, Inc., Ann Arbor, Michigan ADDITION REACTIONS AND PHOTOISOMERIZATION OF CIS,TRANS-1,5“CYCLODECADIENE A Dissertation Submitted to the Graduate Faculty of the Louisiana State University and Agricultural and Mechanical College in partial fulfillment of the requirements for the degree of Doctor of Philosophy in The Department of Chemistry by Hsin-Hsiong Hsieh B.S., Taiwan Provincial Chung-Hsing University, i960 M.S., Louisiana State University,
    [Show full text]
  • Efficient Production of Poly(Cyclohexene Carbonate)
    polymers Article Efficient Production of Poly(Cyclohexene Carbonate) via ROCOP of Cyclohexene Oxide and CO2 Mediated by NNO-Scorpionate Zinc Complexes Sonia Sobrino 1, Marta Navarro 2, Juan Fernández-Baeza 1, Luis F. Sánchez-Barba 2,* , Agustín Lara-Sánchez 1 , Andrés Garcés 2 , José A. Castro-Osma 1 and Ana M. Rodríguez 1 1 Centro de Innovación en Química Avanzada (ORFEO-CINQA), Departamento de Química Inorgánica, Orgánica y Bioquímica, Universidad de Castilla-La Mancha, Campus Universitario, 13071 Ciudad Real, Spain; [email protected] (S.S.); [email protected] (J.F.-B.); [email protected] (A.L.-S.); [email protected] (J.A.C.-O.); [email protected] (A.M.R.) 2 Departamento de Biología y Geología, Física y Química Inorgánica, Universidad Rey Juan Carlos, Móstoles, 28933 Madrid, Spain; [email protected] (M.N.); [email protected] (A.G.) * Correspondence: [email protected]; Tel.: +34-91-488-8504 Received: 4 September 2020; Accepted: 18 September 2020; Published: 21 September 2020 Abstract: New mono- and dinuclear chiral alkoxide/thioalkoxide NNO-scorpinate zinc complexes were easily synthesized in very high yields, and characterized by spectroscopic methods. X-ray diffraction analysis unambiguously confirmed the different nuclearity of the new complexes as well as the variety of coordination modes of the scorpionate ligands. Scorpionate zinc complexes 2, 4 and 6 were assessed as catalysts for polycarbonate production from epoxide and carbon dioxide with no need for a co-catalyst or activator under mild conditions. Interestingly, at 70 ◦C, 10 bar of CO2 pressure and 1 mol % of loading, the dinuclear thioaryloxide [Zn(bpzaepe)2{Zn(SAr)2}] (4) behaves as an efficient and selective one-component initiator for the synthesis of poly(cyclohexene carbonate) via ring-opening copolymerization of cyclohexene oxide (CHO) and CO2, affording polycarbonate materials with narrow dispersity values.
    [Show full text]
  • Chemistry 102 - Experiment 2
    Chemistry 102 - Experiment 2 http://www.miracosta.edu/home/dlr/102exp2.htm Experiment 2 Properties of Alkanes, Alkenes, Aromatic Compounds and an Alcohol In the reactions we will perform in this experiment, hexane will be used to represent the saturated hydrocarbons, cyclohexene will be used as an unsaturated hydrocarbon, and toluene, the aromatic hydrocarbon. Methanol will also be examined. You will use combustion, reactions with halogens and potassium permanganate, as well as solubility to characterize these organic compounds. As a precaution during these experiments, you should be extremely careful since hydrocarbons are extremely flammable. The Bunsen burner, or other sources of flames, will not be used in the laboratory, unless expressly directed by the instructor. The Bunsen burner, or other sources of flames, will not be used in the laboratory, unless expressly directed by the instructor (for the combustion part of this experiment, you will ignite your hydrocarbons using a match). All waste chemicals, both liquids or solids, will be disposed of in the appropriate waste containers. Methyl alcohol is not a hydrocarbon, since it contains the element oxygen, in addition to its carbon and hydrogen atoms. However, alcohols are used during many chemical processes, and like the hydrocarbons, can be used as a fuel. In fact Indy-type race cars (for the Indianapolis 500 race) often use methanol (a 1-carbon alcohol) as a fuel because it burns clean and is saver than conventional fuels because it does not burn as hot. After you do each part of this experiment, write conclusions that you can draw about each of the chemicals used.
    [Show full text]
  • Reaction-Of-Alkenes.Pdf
    8 Reactions of Alkenes Goals for Chapter 8 1 Explain why electrophilic additions are among the most common reactions of alkenes. femoral component 2 Predict the products of the reactions of alkenes, including the orientation of the reaction (regio- polyethylene bearing chemistry) and the stereochemistry. tibial plate 3 Propose mechanisms to explain the observed products of alkene reactions. 4 Use retrosynthetic analysis to solve multistep synthesis problems with alkenes as reagents, intermediates, or products. ◀ Polyethylene provides a self-lubricating surface for movement of the metal parts of an artificial knee replacement. The highly cross-linked polyethylene used in these implants is fabricated to be exceptionally tough: It wears only about 0.1 mm per year. Polyethylene is compatible with the human body, and in most cases, it does not cause a foreign body reaction even after years of constant movement in the joint. The alkene double bond is a gateway functional group. Alkene reactions lead to many other functional groups that lay the foundation for the rest of your study of organic chemistry. You can convert alkenes to alkyl halides, epoxides, alcohols, aldehydes, ketones, carboxylic acids, and other functional groups. The reactions of alkenes arise from the reactivity of their carbon–carbon double bonds. Organic chemists enjoy the challenge of taking a simple carbon–carbon double bond and manipulating it in all possible ways to produce other compounds, often mimicking biological reactions that occur in cells. This chapter covers the most common alkene reactions, including their mechanisms, reactivity, orientation, and stereochemistry. Most reactions of alkenes involve addition of atoms or groups across the double bond, with one atom or group adding to each end.
    [Show full text]
  • Photooxidation of Cyclohexene in the Presence of SO2: SOA Yield and Chemical Composition Shijie Liu1,2,3, Long Jia2, Yongfu Xu2, Narcisse T
    Photooxidation of cyclohexene in the presence of SO2: SOA yield and chemical composition Shijie Liu1,2,3, Long Jia2, Yongfu Xu2, Narcisse T. Tsona1, Shuangshuang Ge2, Lin Du3,1,2 1Environment Research Institute, Shandong University, Jinan, 250100, China 5 2State Key Laboratory of Atmospheric Boundary Layer Physics and Atmospheric Chemistry, Institute of Atmospheric Physics, Chinese Academy of Sciences, Beijing, 100029, China 3Shenzhen Research Institute, Shandong University, Shenzhen, 518057, China Correspondence to: Lin Du ([email protected]); Yongfu Xu ([email protected]) Abstract. Secondary organic aerosol (SOA) formation from cyclohexene/NOx system with various SO2 concentrations 10 under UV light was investigated to study the effects of cyclic alkenes on the atmospheric environment in polluted urban areas. A clear decrease at first and then increase of the SOA yield was found with increasing SO2 concentrations. The lowest SOA yield was obtained when the initial SO2 concentration was in the range of 30-40 ppb, while higher SOA yield compared to that without SO2 could not be obtained until the initial SO2 concentration was higher than 85 ppb. The decreasing SOA yield might be due to the fact that the promoting effect of acid-catalyzed reactions on SOA formation was less important 15 than the inhibiting effect of decreasing OH concentration at low initial SO2 concentrations, caused by the competition reactions of OH with SO2 and cyclohexene. The competitive reaction was an important factor for SOA yield and it should not be neglected in photooxidation reactions. The composition of organic compounds in SOA was measured using several complementary techniques including Fourier transform infrared (FTIR) spectroscopy, ion chromatography (IC) and Exactive-Orbitrap mass spectrometer equipped with electro-spray interface (ESI).
    [Show full text]
  • DIELS-ALDER REACTION of 1,3-BUTADIENE and MALEIC ANHYDRIDE to PRODUCE 4-CYCLOHEXENE-CIS-1,2-DICARBOXYLIC ACID Douglas G. Balmer
    DIELS-ALDER REACTION OF 1,3-BUTADIENE AND MALEIC ANHYDRIDE TO PRODUCE 4-CYCLOHEXENE-CIS-1,2-DICARBOXYLIC ACID Douglas G. Balmer (T.A. Mike Hall) Dr. Dailey Submitted 1 August 2007 Balmer 1 Introduction : The purpose of this experiment is to carry out a Diels-Alder reaction of 1,3- butadiene and maleic anhydride to produce 4-cyclohexene-cis-1,2-dicarboxylic anhydride. This type of reaction is named in honor of the German scientists, Otto Diels and Kurt Alder, who studied the reactions of 1,3-dienes with dienophiles to produce cycloadducts. Their research earned them the 1950 Nobel Prize in chemistry. The saturation of anhydride will be tested with bromine and Bayer tests. It will also be observed that the product is in the cis position and not the trans position which indicates a concerted, single-step, reaction. Finally the product will be hydrolyzed to produce 4- cyclohexene-cis-1,2-dicarboxylic acid. Main Reaction and Mechanism : 3-sulfolene was used to synthesize 1,3-butadiene in the reaction flask. It was easier to start with solid 3-sulfolene and then decompose it, rather than starting with gaseous 1,3-butadiene (Fig.1). The dienophile, maleic anhydride, attacks the diene forming 4- cyclohexene-cis-dicarboxylic anhydride (Fig.2). The final step of the mechanism is to add water to the anhydride to produce 4-cyclohexene-cis-dicarboxylic acid (Fig.3). O 64-65oC S S + O O O FIGURE 1 The decomposition of 3-sulfolene to produce 1,3-butadiene. Balmer 2 O O + O O O O FIGURE 2 The Diels-Alder reaction between 1,3-butadiene and maleic anhydride to produce 4- cyclohexene-cis-1,2-dicarboxylic anhydride .
    [Show full text]
  • Secondary Organic Aerosol Formation from Cyclohexene Ozonolysis: Effect of OH Scavenger and the Role of Radical Chemistryseconda
    Environ. Sci. Technol. 2004, 38, 3343-3350 in the cyclodecene-ozone system, in the presence of propanol Secondary Organic Aerosol scavenger, Ziemann (5) observed the formation of cyclic Formation from Cyclohexene peroxyhemiacetals, and while these products were not shown explicitly to result in an increase in aerosol yield we may Ozonolysis: Effect of OH Scavenger suppose that these large cyclic peroxyhemiacetals partition to the aerosol phase. In contrast to this, Docherty and and the Role of Radical Chemistry Ziemann (1) observed a reduction in SOA yield for the â-pinene ozonolysis when propanol scavenger was used, M. D. KEYWOOD, J. H. KROLL, compared with cyclohexane as a scavenger. V. VARUTBANGKUL, R. BAHREINI, The reaction between cyclohexene and ozone is initiated R. C. FLAGAN, AND J. H. SEINFELD* by the addition of ozone to the double bond to form a primary Departments of Environmental Science and Engineering and ozonide which stabilizes or decomposes to an excited Chemical Engineering, California Institute of Technology, bifunctional Criegee intermediate that has two isomers (5) Pasadena, California 91125 (Figure 1). How this intermediate then goes on to form SOA has been discussed extensively (5, 7-9). The predominant low molecular weight SOA products identified in the cyclo- hexene-ozone system are dicarboxylic acids and hydroxylated To isolate secondary organic aerosol (SOA) formation in dicarboxylic acids (8). Hydroxyl radicals can be produced ozone-alkene systems from the additional influence of hydroxyl from various reactions in the alkene ozonolysis mechanism. (OH) radicals formed in the gas-phase ozone-alkene The dominant pathway of OH formation is understood to be reaction, OH scavengers are employed.
    [Show full text]
  • Synthesis of Cyclohexene the Dehydration of Cyclohexanol
    Synthesis of Cyclohexene The Dehydration of Cyclohexanol. The general approach towards carrying out an organic reaction: (1) Write out the balanced reaction, using structural formulas. (2) Construct a table of relevant information for reactants and products – e.g., MPs, BPs, MWs, densities, hazardous properties. (3) Calculate the correct molar ratios of reactants. Convert moles to grams and milliliters. (4) Mix correct amounts of reactants, solvents, catalysts in correct order to give specific concentrations. Possibly heat or cool or irradiate with UV light, allow to react for necessary amount of time, possibly follow reaction progress using chromatography (e.g., TLC, GC) or spectroscopy (e.g., IR, NMR). (5) After reaction is complete, the reaction mixture is usually a complex mixture of desired product(s), byproducts, unreacted starting materials, solvents, and catalyst. Product may be light, heat, or air (O2) sensitive. (6) Separation and purification steps (so-called reaction work-up). Some combination of extractions, distillations, recrystallizations, chromatography, etc are used for the work-up. (7) Identify product(s) using spectroscopy (IR, NMR, etc), chromatography (GC, TLC, etc), physical properties (MP, BP, etc), and occasionally chemical tests. Cyclohexene. In the presence of a strong acid, an alcohol can be dehydrated to form an alkene. The acid used in this experiment is 85% phosphoric acid and the alcohol is cyclohexanol. The phosphoric acid is a catalyst and as such increases the rate of reaction but does not affect the overall stoichiometry. It can be seen from the balanced reaction that 1 mole of alcohol produces 1 mole of alkene. The theoretical yield of alkene in moles is therefore equal to the number of moles of alcohol used.
    [Show full text]