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  • 1
    Digitale Medien
    Digitale Medien
    New York, NY : Wiley-Blackwell
    International Journal of Chemical Kinetics 17 (1985), S. 957-966 
    ISSN: 0538-8066
    Schlagwort(e): Chemistry ; Physical Chemistry
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Notizen: Rate constants for the gas-phase reactions of NO3 radicals with a series of cycloalkenes have been determined at 298 ± 2 K, using a relative rate technique. Using an equilibrium constant for the NO2 + NO3 ⇄ N2O5 reactions of 3.4 × 10-11 cm3 molecule-1, the following rate constants (in units of 10-13 cm3 molecule-1 s-1) were obtained: cyclopentene, 4.52 ± 0.52; cycloheptene, 4.71 ± 0.56; bicyclo[2.2.1]-2-heptene, 2.41 ± 0.28; bicyclo[2.2.2]-2-octene, 1.41 ± 0.17; bicyclo[2.2.1]-2,5-heptadiene, 9.92 ± 1.13; and 1,3,5-cycloheptatriene, 12.6 ± 2.9. When combined with previous literature rate constants for cyclohexene and 1,4-cyclohexadiene, these data show that the rate constants for the nonconjugated cycloalkenes studied depend to a first approximation on the number of double bonds and the degree and configuration of substitution per double bond. No obvious effects of ring strain energy on these NO3 radical addition rate constants were observed. Our previous a priori predictive techniques for the alkenes and cycloalkenes can now be extended to strained cycloalkenes.
    Zusätzliches Material: 4 Ill.
    Materialart: Digitale Medien
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  • 2
    Digitale Medien
    Digitale Medien
    New York, NY : Wiley-Blackwell
    International Journal of Chemical Kinetics 18 (1986), S. 287-299 
    ISSN: 0538-8066
    Schlagwort(e): Chemistry ; Physical Chemistry
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Notizen: Using a relative rate technique, rate constants for the gas-phase reactions of the OH radical with a series of monoterpenes have been determined in one atmosphere of air at 294 ± 1 K. Relative to a rate constant for the reaction of OH radicals with 2,3-dimethyl-2-butene of 1.12 × 10-10 cm3 molecule-1 sec-1, the rate constants obtained were (in units of 10-11 cm3 molecule-1 sec-1): α-Pinene, 5.45 ± 0.32; β-pinene, 7.95 ± 0.52; Δ3-carene, 8.70 ± 0.43; d-limonene, 16.9 ± 0.5; α-terpinene, 36.0 ± 4.0; γ-terpinene, 17.6 ± 1.8; α-phellandrene, 31.0 ± 7.1; myrcene, 21.3 ± 1.6; and ocimene (acis-, trans-mixture), 25.0 ± 1.9. These are the first quantitative kinetic data reported for many of these monoterpenes. The rate constants obtained are compared with the available literature data and with a priori estimates based on the number and configuration of substituents around the double bond(s). The tropospheric lifetimes of these monoterpenes with OH radicals, NO3 radicals and O3 are estimated and compared. Atmospheric lifetimes with respect to reaction with the OH radical are calculated to range from ∼0.75 hr for α-terpinene to ∼5 hr for α-pinene.
    Zusätzliches Material: 3 Ill.
    Materialart: Digitale Medien
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  • 3
    Digitale Medien
    Digitale Medien
    New York, NY : Wiley-Blackwell
    International Journal of Chemical Kinetics 20 (1988), S. 513-539 
    ISSN: 0538-8066
    Schlagwort(e): Chemistry ; Physical Chemistry
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Notizen: The kinetics of the atmospherically important gas-phase reactions of acenaphthene and acenaphthylene with OH and NO3 radicals, O3 and N2O5 have been investigated at 296 ± 2 K. In addition, rate constants have been determined for the reactions of OH and NO3 radicals with tetralin and styrene, and for the reactions of NO3 radicals and/or N2O5 with naphthalene, 1- and 2-methylnaphthalene, 2,3-dimethylnaphthalene, toluene, toluene-α,α,α-d3 and toluene-d8. The rate constants obtained (in cm3 molecule-1 s-1 units) at 296 ± 2 K were: for the reactions of O3; acenaphthene, 〈5 × 10-19 and acenaphthylene, ca. 5.5 × 10-16; for the OH radical reactions (determined using a relative rate method); acenaphthene, (1.03 ± 0.13) × 10-10; acenaphthylene, (1.10 ± 0.11) × 10-10; tetralin, (3.43 ± 0.06) × 10-11 and styrene, (5.87 ± 0.15) × 10-11; for the reactions of NO3 (also determined using a relative rate method); acenaphthene, (4.6 ± 2.6) × 10-13; acenaphthylene, (5.4 ± 0.8) × 10-12; tetralin, (8.6 ± 1.3) × 10-15; styrene, (1.51 ± 0.20) × 10-13; toluene, (7.8 ± 1.5) × 10-17; toluene-α,α,α-d3, (3.8 ± 0.9) × 10-17 and toluene-d8, (3.4 ± 1.9) × 10-17. The aromatic compounds which were observed to react with N2O5 and the rate constants derived were (in cm3 molecule-1 s-1 units): acenaphthene, 5.5 × 10-17; naphthalene, 1.1 × 10-17; 1-methylnaphthalene, 2.3 × 10-17; 2-methylnaphthalene, 3.6 × 10-17 and 2,3-dimethylnaphthalene, 5.3 × 10-17. These data for naphthylene and the alkylnaphthalenes are in good agreement with our previous absolute and relative N2O5 reaction rate constants, and show that the NO3 radical reactions with aromatic compounds proceed by overall H-atom abstraction from substituent-XH bonds (where X = C or O), or by NO3 radical addition to unsaturated substituent groups while the N2O5 reactions only occur for aromatic compounds containing two or more fused six-membered aromatic rings.
    Zusätzliches Material: 12 Ill.
    Materialart: Digitale Medien
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  • 4
    Digitale Medien
    Digitale Medien
    New York, NY : Wiley-Blackwell
    International Journal of Chemical Kinetics 21 (1989), S. 801-827 
    ISSN: 0538-8066
    Schlagwort(e): Chemistry ; Physical Chemistry
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Notizen: The aromatic ring-retaining products formed from the gas-phase reactions of the OH radical with benzene and toluene, in the presence of NOx, have been identified and their formation yields determined. These products, and their formation yields, are as follows: from benzene - phenol, 0.236 ± 0.044; nitrobenzene, {(0.0336 ± 0.0078) + (3.07 ± 0.92) × 10-16[NO2]}; from toluene - benzaldehyde, 0.0645 ± 0.0080; benzyl nitrate, 0.0084 ± 0.0017; o-cresol, 0.204 ± 0.027; m- + p-cresol, 0.048 ± 0.009; m-nitrotoluene, {(0.0135 ± 0.0029) + (1.90 ± 0.25) × 10-16[NO2]}, where the NO2 concentration is in molecule cm-3 units. The formation yields of o- and p-nitrotoluene from toluene were ca. 0.07 and 0.35 that of m-nitrotoluene, respectively. The observations that the nitro-aromatic yields do not extrapolate to zero as the NO2 concentration approaches zero are not consistent with current chemical mechanisms for these OH radical-initiated reactions, and suggest that under the experimental conditions employed in this study the hydroxycyclohexadienyl radicals formed from OH radical addition to the aromatic ring react with NO2 rather than with O2. However, these data concerning the nitroaromatic yields are consistent with our previous conclusions that many of the nitrated polycyclic aromatic hydrocarbons present in ambient air are formed, at least in part, in the atmosphere from OH radical reactions.
    Zusätzliches Material: 7 Ill.
    Materialart: Digitale Medien
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  • 5
    Digitale Medien
    Digitale Medien
    New York, NY : Wiley-Blackwell
    International Journal of Chemical Kinetics 23 (1991), S. 1003-1015 
    ISSN: 0538-8066
    Schlagwort(e): Chemistry ; Physical Chemistry
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Notizen: The products of the reaction of the hydroxyl (OH) radical with methyl tert-butyl ether (MTBE) in NOx-air systems were identified and measured by Fourier transform infrared absorption spectroscopy and gas chromatography. The products observed, and their yields, were as follows: t-butyl formate, 76 ± 7%; formaldehyde, 37-1+6%; methyl acetate, 17 ± 2%, and acetone, 2.1 ± 0.9%, where the stated error limits represent both random (two standard deviations) and estimated systematic uncertainties. These products account for ca. 95% of the MTBE carbon reacted. Infrared absorption bands which may be due to small amounts of organic nitrate formation were observed, but organic nitrate yields could not be quantified. These data allow a chemical mechanism for the reaction of MTBE with the OH radical in the presence of NOx to be formulated.
    Zusätzliches Material: 4 Ill.
    Materialart: Digitale Medien
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  • 6
    Digitale Medien
    Digitale Medien
    New York, NY : Wiley-Blackwell
    International Journal of Chemical Kinetics 24 (1992), S. 467-480 
    ISSN: 0538-8066
    Schlagwort(e): Chemistry ; Physical Chemistry
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Notizen: Azulene, which is isomeric with naphthalene, was studied to determine whether it behaves like a polycyclic aromatic hydrocarbon or an alkene in its gas-phase reactions with OH and NO3 radicals and O3. Using relative rate methods, rate constants for the reactions of azulene with OH and NO3 radicals and O3 of (2.73 ± 0.56) × 10-10 cm3 molecule-1 s-1, (3.9-1.4+2.0) × 10-10 cm3 molecule-1 s-1, and 〈7 × 10-17 cm3 molecule-1 s-1, respectively, were obtained at 298 ± 2 K. The observation that the NO3 radical reaction did not involve NO2 in the rate determining step indicates that azulene behaves more like an alkene than a polycyclic aromatic hydrocarbon in this reaction. No conclusive evidence for the formation of nitroazulene(s) from either the OH or NO3 radical-initiated reaction of azulene (in the presence of NOx) was obtained.
    Zusätzliches Material: 3 Ill.
    Materialart: Digitale Medien
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  • 7
    Digitale Medien
    Digitale Medien
    New York, NY : Wiley-Blackwell
    International Journal of Chemical Kinetics 24 (1992), S. 983-989 
    ISSN: 0538-8066
    Schlagwort(e): Chemistry ; Physical Chemistry
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Notizen: Using a relative rate method, rate constants for the gas-phase reactions of the OH radical with trans-pinane [(1R, 2R)-2, 6, 6-trimethylbicyclo[3.1.1]heptane], tricyclene (1, 7, 7-trimethyltricyclo[2.2.1.02, 6]heptane), and quadricyclane (quadricyclo[2.2.1.02, 6.03, 5]heptane) of (1.34 ± 0.29) × 10-11 cm3 molecule-1 s-1, (2.86 ± 0.62) × 10-12 cm3 molecule-1 s-1 and (1.83 ± 0.41) × 10-12 cm3 molecule-1 s-1, respectively, have been determined at 296 ± 2 K. These rate constants are compared with values calculated from an empirical estimation method and used to refine this estimation technique for the calculation of OH radical reaction rate constants for polycyclic systems. © John Wiley & Sons, Inc.
    Zusätzliches Material: 1 Ill.
    Materialart: Digitale Medien
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  • 8
    Digitale Medien
    Digitale Medien
    New York, NY : Wiley-Blackwell
    International Journal of Chemical Kinetics 21 (1989), S. 1123-1129 
    ISSN: 0538-8066
    Schlagwort(e): Chemistry ; Physical Chemistry
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Notizen: Using a relative rate method, rate constants for the gas-phase reactions of the OH radical with 1- and 2-propyl nitrate, 1- and 2-butyl nitrate and 1-nitrobutane have been determined in the presence of one atmosphere of air at 298 ± 2 K. Using rate constants for the reactions of the OH radical with propane and cyclohexane of 1.15 × 10-12 and 7.49 × 10-12 cm3 molecule-1 s-1, respectively, following rate constants (in units of 10-12 cm3 molecule-1 s-1) were obtained: 1-propyl nitrate, 0.62; 2-propyl nitrate, 0.41; 1-butyl nitrate, 1.78; 2-butyl nitrate, 0.93; and 1-nitrobutane, 1.35. These rate constants are compared and discussed with the literature data.
    Zusätzliches Material: 3 Ill.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
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  • 9
    Digitale Medien
    Digitale Medien
    New York, NY : Wiley-Blackwell
    International Journal of Chemical Kinetics 22 (1990), S. 59-67 
    ISSN: 0538-8066
    Schlagwort(e): Chemistry ; Physical Chemistry
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Notizen: Using a relative rate technique, rate constants for the gas-phase reactions of the OH radical with the three cresols and the six dimethylphenols have been determined at 296 ± 2 K and atmospheric pressure. The rate constants for the cresols, which range from 4.3 × 10-11 cm3molecule-1 s-1to 6.8 × 10-11 cm3molecule-1 s-1, are in good agreement with previous literature data. The rate constants for 2,3-, 2,4-, 2,5-, 2,6-, and 3,4-dimethylphenol are all in the range (6.6-8.1) × 10-11 cm3 molecule-1 s-1, with the rate constant for 3,5-dimethylphenol being somewhat higher at 1.13 × 10-10 cm3 molecule-1 s-1. Rate constants estimated from the number, identity, and positions of the substituent groups around the aromatic ring agree to within a factor of approximately 2 with these experimentally determined rate constants.
    Zusätzliches Material: 4 Ill.
    Materialart: Digitale Medien
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  • 10
    Digitale Medien
    Digitale Medien
    New York, NY : Wiley-Blackwell
    International Journal of Chemical Kinetics 22 (1990), S. 981-998 
    ISSN: 0538-8066
    Schlagwort(e): Chemistry ; Physical Chemistry
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Notizen: The kinetics of the gas-phase reactions of allyl chloride and benzyl chloride with the OH radical and O3 were investigated at 298 ± 2 K and atmospheric pressure. Direct measurements of the rate constants for reactions with ozone yielded values of k(O3 + allyl chloride) = (1.60 ± 0.18) × 10-18 cm3 molecule-1 s-1 and k(O3 + benzyl chloride) 〈 6 × 10-20 cm3 molecule-1 s-1. With the use of a relative rate technique and ethane as a scavenger of chlorine atoms produced in the OH radical reactions, rate constants of k(OH + allyl chloride) = (1.69 ± 0.07) × 10-11 cm3 molecule-1 s-1 and k(OH + benzyl chloride) = (2.80 ± 0.19) × 10-12 cm3 molecule-1 s-1 were measured. A study of the OH radical reaction with allyl chloride by long pathlength FT-IR absorption spectroscopy indicated that the co-products ClCH2CHO and HCHO account for ca. 44% of the reaction, and along with the other products HOCH2CHO, (ClCH2)2CO, and CH2 = CHCHO account for 84 ± 16% of the allyl chloride reacting. The data indicate that in one atmosphere of air in the presence of NO the chloroalkoxy radical formed following OH radical addition to the terminal carbon atom of the double bond decomposes to yield HOCH2CHO and the CH2Cl radical, which becomes a significant source of the Cl atoms involved in secondary reactions. A product study of the OH radical reaction with benzyl chloride identified only benzaldehyde and peroxybenzoyl nitrate in low yields (ca. 8% and ≤4%, respectively), with the remainder of the products being unidentified.
    Zusätzliches Material: 6 Ill.
    Materialart: Digitale Medien
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