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  • 1
    Electronic Resource
    Electronic Resource
    Chichester : Wiley-Blackwell
    Journal of Physical Organic Chemistry 7 (1994), S. 585-590 
    ISSN: 0894-3230
    Keywords: Organic Chemistry ; Physical Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: The title sulphenamides were pyrolysed in a stirred-flow reactor at temperatures of 310-410°C, pressures of 8-15 Torr and residence times of 0·4-2 s using toluene as the carrier gas. N-(tert-Butylthio)allylamine formed 73 ± 4% isobutene, 23 ± 3% propene and N-allylthiohydroxylamine. The first-order rate coefficients for the formation of isobutene and propene, respectively, followed the Arrhenius equations kC4(s-1) = 1012·52 ± 0·36 exp(-163 ± 5 kJ mol-1 RT) and kC3(s-1) = 1010·99 ± 0·29 exp(-151 ± 4 kJ mol-1 RT) N-(tert-Butylthio)diethylamine gave 97 ± 1% isobutene, 1·9 ± 0·4% isobutane and N,N-diethylthiohydroxylamine. The first-order rate coefficients for isobutene elimination followed the Arrhenius equation k(s-1) = 1013·45 ± 0·24 exp(-164 ± 3 kJ mol-1 RT). The formation of the products is interpreted in terms of an elimination reaction with a unimolecular, four-centered, cyclic transition state. The reactivity of these sulphenamides was found to be much higher than that of previously studied alkyl or aryl tert-butyl sulphides and disulphides.
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  • 2
    Electronic Resource
    Electronic Resource
    Chichester : Wiley-Blackwell
    Journal of Physical Organic Chemistry 3 (1990), S. 414-418 
    ISSN: 0894-3230
    Keywords: Organic Chemistry ; Physical Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: The rate and endo/exo selectivity of the Diels-Alder reaction between cyclopentadiene and methyl (E)-α-cyanocinnamate at 25°C, in several acetone-water and 1,4-dioxane-water mixtures, were measured. The linear correlations of log k and log(endo/exo) vs solvophobicity are reported. Correlations for selectivity are considerably improved when the results obtained in acetone-water and 1,4-dioxane-water are taken as separate series.
    Additional Material: 5 Ill.
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  • 3
    Electronic Resource
    Electronic Resource
    New York, NY : Wiley-Blackwell
    International Journal of Chemical Kinetics 26 (1994), S. 743-747 
    ISSN: 0538-8066
    Keywords: Chemistry ; Physical Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: An exceptional kinetic behavior on the reactivity of β-diketones against copper(II) have been found. Some relationship between ligand basicity and unexpected enhancement on the rates of complex formation, which may be useful for predicting rate constants of similar monochelated copper(II) complexes, are established. © 1994 John Wiley & Sons, Inc.
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  • 4
    Electronic Resource
    Electronic Resource
    New York, NY : Wiley-Blackwell
    International Journal of Chemical Kinetics 30 (1998), S. 121-127 
    ISSN: 0538-8066
    Keywords: Chemistry ; Physical Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: From a study of the complexation of FeIII with 2,6-dimethyl-3,5-heptanedione in aqueous solution, thermodynamic and kinetic parameters have been obtained. Results obtained for this system and a series of structurally similar iron(III) diketonates at different temperatures, establishes isokinetic behaviors of these kinds of reactions.Analytical correlations obtained may be useful to predict, for analogous ligands in similar experimental conditions, an essential mechanism, that pathways involving reaction of metal-hydrolyzed species with the enol tautomer are faster than pathways involving hexa-aqua species. Additionally, thermodynamic parameters associated with the monochelated complexations may be predicted. © 1998 John Wiley & Sons, Inc. Int J Chem Kinet 30: 121-127, 1998.
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  • 5
    Electronic Resource
    Electronic Resource
    New York, NY : Wiley-Blackwell
    International Journal of Chemical Kinetics 27 (1995), S. 99-108 
    ISSN: 0538-8066
    Keywords: Chemistry ; Physical Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The title amines were pyrolyzed in a stirred-flow reactor at 380-510°C, pressures of 8-15 torr and residence times of 0.3-2.4 s, using toluene as carrier gas. The substrates with an allyl group yielded propene and iminonitriles as reaction products. HCN is formed by decomposition of the iminonitriles. The first-order rate coefficients for propene formation fit the Arrhenius equations Allyl cyanomethyl amine:\documentclass{article} \pagestyle{empty} \begin{document} $$ k({\rm s}^{ - {\rm 1}}) = 10^{13.29 \pm 0.35} {\rm exp(} - {\rm 189} \pm 5{\rm kJ/mol }RT{\rm)} $$ \end{document}Diallyl cyanomethyl amine:\documentclass{article} \pagestyle{empty} \begin{document} $$ k({\rm s}^{ - {\rm 1}}) = 10^{13.00 \pm 0.20} {\rm exp(} - {\rm 183} \pm 3{\rm kJ/mol }RT{\rm)} $$ \end{document} Diethyl cyanomethyl amine gave a 20:1 gas mixture of ehylene and ethane, plus HCN. The liquid product fraction contained mainly N-ethyl methanaldimine. The first-order rate coefficients for ethylene formation followed the Arrhenius equation \documentclass{article}\pagestyle{empty}\begin{document}$$ k({\rm s}^{ - {\rm 1}}) = 10^{15.30 \pm 0.24} {\rm exp(} - {\rm 226} \pm 3{\rm kJ/mol }RT{\rm)} $$\end{document} Diethyl propargyl amine decomposed cleanly into allene and N-ethyl ethanaldimine. The first-order rate coefficients for allene formation fit the Arrhenius equation \documentclass{article}\pagestyle{empty}\begin{document}$$ k({\rm s}^{ - {\rm 1}}) = 10^{12.84 \pm 0.30} {\rm exp(} - {\rm 168} \pm 4{\rm kJ/mol }RT{\rm)} $$\end{document} The results suggest that the above allyl and propargyl amines decompose unimolecularly by mechanisms involving six-center cyclic transition states. For diethyl cyanomethyl amine, a nonchain free radical mechanism is proposed. © 1995 John Wiley & Sons, Inc.
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  • 6
    Electronic Resource
    Electronic Resource
    New York, NY : Wiley-Blackwell
    International Journal of Chemical Kinetics 28 (1996), S. 353-359 
    ISSN: 0538-8066
    Keywords: Chemistry ; Physical Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The amide derivatives of t-butylsulfenic acid mentioned in the title have been thermolyzed in a stirred-flow reactor at temperatures of 273-390°C and pressures of 7-15 torr, using toluene as carrier gas, at residence times of 0.4-2 s. Isobutene formed in 95-99% yields, through order one reactions, following the Arrhenius equations: N, N-dimethyl t-butylsulfenamide: $$k(s^{-1})=10^{14.45\pm 0.46}\exp(-175\pm 5 {\rm kJ/mol}\,{\bf RT})$$ 2,6-dimethylpiperidyl t-butylsulfenamide: $$k(s^{-1})=10^{14.38\pm 0.26}\exp(-161\pm 3 {\rm kJ/mol}\,{\bf RT})$$ N-t-butyl t-butylsulfenamide: $$k(s^{-1})=10^{14.75\pm 0.37}\exp(-184\pm 7 {\rm kJ/mol}\,{\bf RT})$$These thermolyses are considered to take place through unimolecular, four-center cyclic transition-state reaction mechanisms, giving rise to isobutene plus the corresponding S-unsubstituted thiohydroxylamines. The latter decompose outside the reactor at temperatures above -78°C forming free sulfur and dimethylamine, 2,6-dimethylpiperidine, and t-butylamine, respectively. © 1996 John Wiley & Sons, Inc.
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  • 7
    Electronic Resource
    Electronic Resource
    New York, NY : Wiley-Blackwell
    International Journal of Chemical Kinetics 24 (1992), S. 631-638 
    ISSN: 0538-8066
    Keywords: Chemistry ; Physical Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: N-t-butylaniline, N-t-butyl-p-anisidine, and N-t-butyl-p-nitroaniline have been pyrolyzed in a stirred-flow reactor at 510-620°C, 8-15 torr total pressure, and 0.5-1.5 s contact time, using toluene as carrier gas. An order one kinetics was observed for the consumption of the amines. The reactions yielded 95 ± 2% isobutene plus the corresponding anilines as reaction products. The rate coefficients followed the Arrhenius equations N-t-butylaniline \documentclass{article}\pagestyle{empty}\begin{document}$$ k = 10^{14.19 \pm 0.32} \exp (- 234 \pm 5\,{\rm kJ/mol}\, RT) $$\end{document} N-t-butyl-p-anisidine \documentclass{article}\pagestyle{empty}\begin{document}$$ k = 10^{13.05 \pm 0.23} \exp (- 208 \pm 4\,{\rm kJ/mol}\, RT) $$\end{document} N-t-butyl-p-nitroaniline \documentclass{article}\pagestyle{empty}\begin{document}$$ k = 10^{13.73 \pm 0.28} \exp (- 235 \pm 6\,{\rm kJ/mol}\, RT) $$\end{document}The results are consistent with an unimolecular elimination of isobutene involving polar four-center cyclic transition states. © John Wiley & Sons, Inc.
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  • 8
    Electronic Resource
    Electronic Resource
    New York, NY : Wiley-Blackwell
    International Journal of Chemical Kinetics 30 (1998), S. 451-456 
    ISSN: 0538-8066
    Keywords: Chemistry ; Physical Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: N-cyanomethyl-N-ethyl aniline (CEAN) and N-cyanomethyl-N-ethyl-p-anisidine (CEPA) have been thermolyzed in a stirred-flow reactor, in the range of 510-560 °C, pressures of 7-11 torr and residence times of 0.5-0.9 s, using toluene as carrier gas. N-cyanomethyl-N-ethyl-p-nitroaniline (ECNA) was thermolyzed at 640°C and 13% conversion. Ethylene and HCN formed in 43% yield each as products from all three starting materials. Phenyl methanaldimine and p-anisidyl methanaldimine were also products of CEAN and CEPA, respectively. The consumption of CEAN and CEPA showed first-order kinetics for a three-fold increase of reactant inflow and initial conversions of up to 40 percent. The following Arrhenius equations were obtained from the rate coefficients for the production of ethylene: CEAN: k=1015.10±0.74 exp(-238±11 kJ/mol·RT); CEPA: k=1015.61±0.29 exp(-246±4 kJ/mol·RT). The results are explained by means of radical, nonchain thermolysis mechanisms. The thermochemistry of relevant reaction steps has been estimated from thermochemical parameters calculated by using the semiempirical AM1 method. © 1998 John Wiley & Sons, Inc. Int J Chem Kinet: 30: 451-456, 1998
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  • 9
    ISSN: 0538-8066
    Keywords: Chemistry ; Physical Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The kinetics of formation of the 1:1 complexes of some dialkyl-2,2′-bipyridyl-5,5′-dicarboxylates with the ion of Ni(II) have been determined by the stopped-flow spectrophotometric method. Second-order formation rate constants have been correlated with the Taft modification of the Hammett equation. A linear regression has been found (P = 0.95 confidence) with the following characteristics: slope = -0.6 ± 0.1; intercept = 1.32 ± 0.02 (log k0). An inductive effect of the alkyl groups upon the reaction of the complexation is proposed.
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  • 10
    Electronic Resource
    Electronic Resource
    New York, NY : Wiley-Blackwell
    International Journal of Chemical Kinetics 25 (1993), S. 1005-1013 
    ISSN: 0538-8066
    Keywords: Chemistry ; Physical Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The kinetics and mechanism of the reaction of complexation of iron(III) with 2,4-octanedione and 2,4-nonanedione have been investigated spectrophotometrically in aqueous solution at 10°C and ionic strength 0.5 mol dm-3 NaClO4. The equilibrium constants of the mono-complexes have been determined. The mechanism proposed to account for the kinetic data involves a double reversible pathway where both Fe3+ and Fe(OH)2+ react with the enol tautomer of the ligand. 2,4-Octanedione reacts with Fe3+ and Fe(OH)2+ with rate constants of 0.65 dm3 mol-1 s-1, and 14.07 dm3 mol-1 s-1, respectively. For 2,4-nonanedione complexation the rate constants determined are 0.49 dm3 mol-1 s-1, and 11.39 dm3 mol-1 s-1, respectively. Some discussions are made on the basis of Eigen-Wilkins theory considering the effect of solvent exchange on the complex formation. © 1993 John Wiley & Sons, Inc.
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