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  • 1
    Electronic Resource
    Electronic Resource
    Addition of methoxy radicals to olefins (1975)
    New York, NY : Wiley-Blackwell
    International Journal of Chemical Kinetics 7 (1975), S. 625-631 
    Details
    ISSN: 0538-8066
    Keywords: Chemistry ; Physical Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The addition of methoxy radicals to several olefins has been studied by a competitive method at 127°C in gas phase. The thermal decomposition of dimethyl peroxide was used as methoxy radical source. The rate of addition to the double bond was measured relative to the oxidation of carbon monoxide. For the addition to ethylene it was obtained that \documentclass{article}\pagestyle{empty}\begin{document}$$ k_{{\rm add}} = \left({3.7 \pm 0.8} \right) \times 10^4 M^{ - 1} \cdot {\rm s}^{{\rm - 1}} $$\end{document} This rate constant is similar to the one shown by methyl radicals under similar conditions. From the relative rate of addition to several chlorinated and fluorinated olefins it can be concluded that methoxy radicals show very little “electrophilic” character.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/kin.550070411
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  • 2
    Electronic Resource
    Electronic Resource
    Cage reactions in the photolysis of 2,2,4,4-tetramethyl-3-pentanone (1984)
    New York, NY : Wiley-Blackwell
    International Journal of Chemical Kinetics 16 (1984), S. 503-511 
    Details
    ISSN: 0538-8066
    Keywords: Chemistry ; Physical Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The product quantum yields in the photolysis of 2,2,4,4-tetramethyl-3-pentanone have been measured in homogeneous solvents of different viscosities, in micellar solutions of cetyltrimethylammonium chloride and sodium dodecyl sulfate, and in dioctadecyl ammonium chloride vesicles.The product quantum yield in n-heptane was found to be 1. This value decreases to 0.5 in paraffin oil as a consequence of geminate recombination. In the presence of free radical scavengers, the extent of geminate disproportionation can be evaluated from the yields of isobutene and 2,2-dimethyl propionaldehyde. From these yields and the geminate recombination yields the total amount of geminate processes and the disproportionation-to-combination ratio for caged radicals are estimated. It is found that micelles provide the most efficient cages. In these media only about 10% of the radicals avoid cage processes. The disproportionation-to-combination ratio of tert-butyl and pivaloyl radicals was found to be extremely media dependent. The measured values ranged from about 0.2 in paraffin oil to 0.8 in cetyltrimethylammonium chloride micelles.
    Additional Material: 2 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/kin.550160502
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  • 3
    Electronic Resource
    Electronic Resource
    Reactivity of tert-butoxy radicals towards thiols, alkyl sulfides, and alkyl disulfides (1989)
    New York, NY : Wiley-Blackwell
    International Journal of Chemical Kinetics 21 (1989), S. 245-250 
    Details
    ISSN: 0538-8066
    Keywords: Chemistry ; Physical Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Rate constants for the reactions of tert-butoxy radicals (generated by the thermal decomposition of di-tert-butylperoxyoxalate) with several sulfur containing compounds have been measured at 310 K in benzene. Hexanethiol (k = 6.5 × 107M-1s-1) reacts considerably faster than alkyl sulfides and disulfides. For these compounds the reaction rate constants are slightly dependent on the α-hydrogen type, changing (when it is expressed per hydrogen atom) only a factor 5 for sulfides and 3 for disulfides when the α-hydrogen is changed from primary (methyl) to tertiary (isopropyl). The data obtained are compared to those found for the deactivation of the benzophenone triplet. Values of ktert-butoxy/kbenzophenone range from ca 10-3 (di-tert-butyl disulfide) to 7.5 (hexanethiol). The results obtained are rationalized in terms of bond strength, steric hindrance, and charge transfer contributions to the critical configuration energies.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/kin.550210404
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  • 4
    Electronic Resource
    Electronic Resource
    Kinetics of the reaction between 2,2′-azinobis (3-ethylbenzothiazoline-6-sulfonic acid (ABTS) derived radical cations and phenols (1997)
    New York, NY : Wiley-Blackwell
    International Journal of Chemical Kinetics 29 (1997), S. 219-224 
    Details
    ISSN: 0538-8066
    Keywords: Chemistry ; Physical Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The reaction between the radical cation derived from 2,2′-azinobis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) and phenols follows a kinetic law given by \documentclass{article}\pagestyle{empty}\begin{document}$$ d[ABTS^{\buildrel{+}\over{\cdot}}]/dt=k [ABTS^{\buildrel{+}\over{\cdot}}]^2[PhOH]/[ABTS] $$\end{document} with stoichiometric coefficients between one and two. The rate constant is almost unrelated to the structure of the phenol, while the number of ABTS radicals scavenged by each phenol molecule increases with para-substitution. These results are explained in terms of a fast, reversible electron transfer \documentclass{article}\pagestyle{empty}\begin{document}$$ ABTS^{\buildrel{+}\over{\cdot}}\,+PhOH {\buildrel{\longrightarrow}\over{\longleftarrow}} ABTS + PhO\bullet+H^{+} $$\end{document} followed by the self-combination of the phenoxy radicals and/or their reaction with another ABTS derived radical action. The relative rate of these processes determine the value of the stoichiometric coefficient. © 1997 John Wiley & Sons, Inc. Int J Chem Kinet 29: 219-224, 1997.
    Additional Material: 7 Ill.
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  • 5
    Electronic Resource
    Electronic Resource
    Reaction of 2,2′-azinobis (3-ethylbenzothiazoline-6-sulfonic acid (ABTS) derived radicals with hydroperoxides. Kinetics and mechanism (1998)
    New York, NY : Wiley-Blackwell
    International Journal of Chemical Kinetics 30 (1998), S. 565-570 
    Details
    ISSN: 0538-8066
    Keywords: Chemistry ; Physical Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Tert-Butyl hydroperoxide and hydrogen peroxide readily react with the radical cation derived from 2,2′-azinobis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS). The reaction is inhibited by ABTS and protons, and can be interpreted in terms of a mechanism comprising a partially reversible electron transferROOH+ABTS•+↔ ROO · + ABTS + H+ (1)followed by the self-reactions of the hydroperoxide derived radicals and reactions between them and another ABTS derived radical. A complete kinetic analysis allows an evaluation of the rate constant for reaction (1). A value of 0.2 M-1 s-1 was obtained for both compounds. The back reaction of process (1) is more relevant when tert-butyl hydroperoxide is employed. © 1998 John Wiley & Sons, Inc. Int J Chem Kinet 30: 565-570, 1998
    Additional Material: 5 Ill.
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  • 6
    Electronic Resource
    Electronic Resource
    Decomposition of di-tert-butyl nitroxide in aqueous solutions (1985)
    New York, NY : Wiley-Blackwell
    International Journal of Chemical Kinetics 17 (1985), S. 109-116 
    Details
    ISSN: 0538-8066
    Keywords: Chemistry ; Physical Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Di-tert-butyl nitroxide (DTBN) decomposes in aqueous solutions producing 2-methyl-2-nitroso propane (MNP) and tert-butanol. The process is acid catalyzed, it is of second order in DTBN, and takes place with a rate constant of (1.0 ± 0.1) M-2 s-1. The reaction is also catalyzed by the anionic surfactant sodium dodecyl sulfate and by Fe(II) and Fe(III) ions. The catalysis by Fe(III) involves a very fast reduction of Fe(III) ions with concomitant formation of 2-methyl-2-nitroso propane. The reaction catalyzed by Fe(II) also produces 2-methyl-2-nitroso propane with a formation rate given by: d[MNP]/dt = (0.25 ± 0.10) [Fe(II)] [DTBN]. This reaction rate is nearly pH independent.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/kin.550170110
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  • 7
    Electronic Resource
    Electronic Resource
    Reactivity of tert-butoxyl radicals towards substituted indole derivatives (1991)
    New York, NY : Wiley-Blackwell
    International Journal of Chemical Kinetics 23 (1991), S. 761-766 
    Details
    ISSN: 0538-8066
    Keywords: Chemistry ; Physical Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Tert-butoxyl radicals react with indole and methyl substituted derivatives by hydrogen abstraction. For those compounds which are unsubstituted at the N-atom, hydrogen abstraction takes place almost exclusively at the N—H bond. The reactivity of these compounds correlates with their donor electron capacity, pointing to significant contribution of charge transfer to the transition state stability. Substitution at the N atom considerably decreases the reactivity.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/kin.550230902
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  • 8
    Electronic Resource
    Electronic Resource
    Autooxidation of diethyl hydroxylamine (1978)
    New York, NY : Wiley-Blackwell
    International Journal of Chemical Kinetics 10 (1978), S. 1167-1182 
    Details
    ISSN: 0538-8066
    Keywords: Chemistry ; Physical Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The autooxidation of diethyl hydroxylamine (DEHA) has been studied both in solution and in the gas phase between 0° and 60°C. The results obtained are interpreted in terms of a nonchain free radical mechanism in which reaction (1) is the rate-determining step. This reaction is followed by the reaction of HO2 radicals with DEHA to give hydrogen peroxide. The initial stoichiometry is given by \documentclass{article}\pagestyle{empty}\begin{document}$$ {\rm 2DEHA + O}_{\rm 2} \to {\rm 2nitrone + 2H}_{\rm 2} {\rm O} $$\end{document} which implies that the hydrogen peroxide reacts with DEHA to give water and diethyl nitroxide radicals.The activation energy of reaction (1) is 16.5 ± 2 kcal/mol, leading to a dissociation energy of 69.5 ± 2 kcal for the O=H bond in DEHA.The oxidation of DEHA in the gas phase is nearly ten times slower than that observed in chlorobenzene solution under similar experimental conditions. This result is related to the stabilization of the free radicals produced by the solvent.
    Additional Material: 10 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/kin.550101107
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  • 9
    Electronic Resource
    Electronic Resource
    On the reactivity of amines toward tert-butoxy radicals (1978)
    New York, NY : Wiley-Blackwell
    International Journal of Chemical Kinetics 10 (1978), S. 653-656 
    Details
    ISSN: 0538-8066
    Keywords: Chemistry ; Physical Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/kin.550100611
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  • 10
    Electronic Resource
    Electronic Resource
    Reaction of di-tert-butylnitroxide radicals (1980)
    New York, NY : Wiley-Blackwell
    International Journal of Chemical Kinetics 12 (1980), S. 871-881 
    Details
    ISSN: 0538-8066
    Keywords: Chemistry ; Physical Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Di-tert-butylnitroxide (DTBN) is the simplest of the stable nitroxide radicals and is only consumed at temperatures higher than 90°C or in the presence of very reactive substrates. The pyrolysis of DTBN in solution gives, at least at low conversion, 2-methyl-2-nitrosopropane and di-tert-butylnitroxide-tert-butyl ether. The reaction involves, as the rate-limiting step, the cleavage of the C—N bond. This reaction takes place with an activation energy of 33 kcal/mol. DTBN is stable in the presence of styrene, aldehydes, hydrogen peroxide, α-methyl-N-ethyl nitrone, phenol, and triphenylmethane. On the other hand, it reacts readily with diethylhydroxylamine, ascorbid acid, ethanethiol, and hexanethiol. For the two former compounds the reaction involves a hydrogen transfer as the rate-determining step, and the reaction proceeds, a low conversion, with simple second-order kinetics. The reaction with the thiols is complex and shows a clear inductiontime.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/kin.550121106
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