Library

X
feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
  • 11
    Electronic Resource
    Electronic Resource
    Neighboring group participation of polar β substituents in the gas-phase pyrolysis of 2-substituted ethyl chlorides (1979)
    New York, NY : Wiley-Blackwell
    International Journal of Chemical Kinetics 11 (1979), S. 109-115 
    Details
    ISSN: 0538-8066
    Keywords: Chemistry ; Physical Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The pyrolysis of 2-dimethylaminoethyl chloride in the temperature range of 360-400°C and the pressure range of 60-271 mmHg is a homogeneous, unimolecular, first-order reaction giving dimethylvinyl amine and hydrogen chloride. 2-Methoxyethyl chloride pyrolysis in the temperature range of 450-490°C and the pressure range of 53-110 mmHg by a similar unimolecular, first-order reaction yields methylvinyl ether and hydrogen chloride. These reactions were carried out in a seasoned reaction vessel and in the presence of a propene inhibitor. The methylvinyl ether decomposes slowly into other products at the temperature of pyrolysis. The rate constants are given by the Arrhenius equations(a) 2-dimethylaminoethyl chloride: \documentclass{article}\pagestyle{empty}\begin{document}$$ \log k(\sec ^{ - 1}) = (13.22 \pm 0.17) - (203.7 \pm 2.1)kJ/mol/2.303RT $$\end{document}(b) 2-methoxyethyl chloride: \documentclass{article}\pagestyle{empty}\begin{document}$$ \log k(\sec ^{ - 1}) = (14.06 \pm 0.53) - (244.7 \pm 7.1)kJ/mol/2.303RT $$\end{document}The effects of polar β substituents in the 2 position of ethyl chloride are discussed in terms of anchimeric assistance and electron-withdrawing deactivation in these elimination reactions. The present results are consistent with the heterolytic nature of the four-centered cyclic transition state for the gas-phase pyrolysis of alkyl halides.
    Additional Material: 4 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/kin.550110202
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 12
    Electronic Resource
    Electronic Resource
    Effect of substituents in the gas-phase elimination kinetics of β-substituted ethyl acetates (1979)
    New York, NY : Wiley-Blackwell
    International Journal of Chemical Kinetics 11 (1979), S. 561-567 
    Details
    ISSN: 0538-8066
    Keywords: Chemistry ; Physical Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The kinetics of gas-phase elimination of 3-methyl-1-butyl acetate and 3,3-dimethyl-1-butyl acetate into acetic acid and the corresponding substituted butenes have been measured over the temperature range of 360-420°C and the pressure range of 63-250 Torr. The reactions are homogeneous in both clean and seasoned vessels, obey first-order law, and are unimolecular. The temperature dependence of the rate constants is given by the Arrhenius equation3-methyl-1-butyl acetate: \documentclass{article}\pagestyle{empty}\begin{document}$$ {log k(sec}^{{ - 1}} {) = (12}{.73 } \pm { 0}{.29) - (202}{.5 } \pm { 3}{.8) kJ/mol/2}{.303}RT $$\end{document}3,3-dimethyl-1-butyl acetate: \documentclass{article}\pagestyle{empty}\begin{document}$$ {log k(sec}^{{ - 1}} {) = (12}{.34 } \pm { 0}{.35) - (194}{.1 } \pm { 4}{.2) kJ/mol/2}{.303}RT $$\end{document} The points in a plot of log (k/k0) of β-alkyl and several β-substituted ethyl acetates against Es values appear aligned in an approximate linear relationship. These results may be interpreted as a consequence of steric effects, namely, steric accelerations.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/kin.550110602
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 13
    Electronic Resource
    Electronic Resource
    Neighboring olefinic double-bond participation in gas phase pyrolysis of some alkenyl chlorides (1979)
    New York, NY : Wiley-Blackwell
    International Journal of Chemical Kinetics 11 (1979), S. 1279-1286 
    Details
    ISSN: 0538-8066
    Keywords: Chemistry ; Physical Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: 4-Chloro-1-butene, 5-chloro-1-pentene, and 6-chloro-1-hexene have been shown to decompose, in a static system, mainly to hydrogen chloride and the corresponding alkadienes. In packed and unpacked clean Pyrex vessels the reactions were significantly heterogeneous. However, in a vessel seasoned with allyl bromide these reactions were homogeneous, unimolecular, and follow a first-order law. The working temperature range was 389.6-480.0°C and with a pressure range of 53-221 Torr. The rate constants for the homogeneous reactions were expressed by the following Arrhenius equations: 4-chloro-1-butene: logk(sec-1) = (13.79 ± 0.17) - (223.8 ± 2.1)kJ/mole/2.303RT; 5-chloro-1-pentene: logk(sec-1) = (14.25 ± 1.20) - (238.4 ± 12.7)kJ/mole/2.303RT; and 6-chloro-1-hexene: logk(sec-1) = (12.38 ± 0.22) - (209.6 ± 2.9)kJ/mole/2.303RT. The olefinic double bond has been found to participate in the rate of dehydrohalogenation of 4-chloro-1-butene. The insulation of the CH2=CH in chlorobutene by one or two methylene chains to the reaction center does not indicate neighboring group participation. The three-membered conformation is the most favored structure for anchimeric assistance of the double bond in gas phase pyrolysis of alkenyl chlorides. The heterolytic nature of these eliminations is also supported by the present work.
    Additional Material: 5 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/kin.550111207
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 14
    Electronic Resource
    Electronic Resource
    Kinetics of the gas-phase elimination of isopropyl α-substituted acetates (1978)
    New York, NY : Wiley-Blackwell
    International Journal of Chemical Kinetics 10 (1978), S. 893-897 
    Details
    ISSN: 0538-8066
    Keywords: Chemistry ; Physical Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: No. Abstract.
    Additional Material: 2 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/kin.550100809
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 15
    Electronic Resource
    Electronic Resource
    The participation of aromatic neighboring groups in gas-phase elimination reactions (1978)
    New York, NY : Wiley-Blackwell
    International Journal of Chemical Kinetics 10 (1978), S. 923-929 
    Details
    ISSN: 0538-8066
    Keywords: Chemistry ; Physical Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The gas-phase pyrolysis of 2-chloroethylbenzene and p-methoxy-2-chloroethylbenzene was studied in a static system over the temperature range of 411°-471°C and a pressure range of 39-202 mm Hg. The reactions in seasoned vessels, with the propene inhibitor always present, were homogeneous, first-order, and unimolecular. The rate constants are given by the Arrhenius equation for 2-chloroethylbenzene: \documentclass{article}\pagestyle{empty}\begin{document}$$ \log k(\sec ^{- 1}) = (13.07 \pm 0.35) - (220.9 \pm 4.6){\rm kJ/mol/2}{\rm .303}RT $$\end{document} and for p-methoxy-2-chloroethylbenzene: \documentclass{article}\pagestyle{empty}\begin{document}$$ \log k(\sec ^{- 1}) = (13.81 \pm 0.34) - (228.4 \pm 4.6){\rm kJ/mol/2}{\rm .303}RT $$\end{document} The presence of phenyl substituents in the β position of ethyl chloride has been found to provide anchimeric assistance in these elimination reactions.
    Additional Material: 5 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/kin.550100903
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 16
    Electronic Resource
    Electronic Resource
    The elimination kinetics of 2-bromo-3-methylbutyric acid in the gas phase (1995)
    New York, NY : Wiley-Blackwell
    International Journal of Chemical Kinetics 27 (1995), S. 85-88 
    Details
    ISSN: 0538-8066
    Keywords: Chemistry ; Physical Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The kinetics of 2-bromo-3-methylbutyric acid in the gas phase was studied over the temperature range of 309.3-357.0°C and pressure range of 15.5-100.0 torr. This process, in seasoned static reaction vessels and in the presence of the free radical inhibitor cyclohexene, is homogeneous, unimolecular, and follows first-order rate law. The observed rate coefficients are represented by the following Arrhenius equations: log k1(s-1) = (12.72 ± 0.25) - (181.8 ± 2.9) kJ mol-1 (2.303RT)-1. The primary products are isobutyraldehyde, CO, and HBr. The polar five-membered cyclic transition state type of mechanism appears to be preferred in the dehydrohalogenation process of α-haloacids in the gas phase. © 1995 John Wiley & Sons, Inc.
    Additional Material: 6 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/kin.550270110
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 17
    Electronic Resource
    Electronic Resource
    The gas-phase pyrolysis of several aliphatic 1,3-diols. The kinetic and mechanism of 2,4-dimethyl-2,4-pentanediol (1997)
    New York, NY : Wiley-Blackwell
    International Journal of Chemical Kinetics 29 (1997), S. 851-854 
    Details
    ISSN: 0538-8066
    Keywords: Chemistry ; Physical Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Satisfactory kinetic determinations of several aliphatic 1,3-diols were difficult to obtain. Moreover the product distributions from each of these substrates suggest complex parallel mechanisms. However, the elimination kinetic of 2,4-dimethyl-2,4-pentanediol has been measured over the temperature range of 419.7-459.9°C and pressure range of 47-115 torr. The reaction carried out by employing a static system, in seasoned vessel, and in the presence of the free-radical inhibitor propene, proved to be homogeneous, unimolecular, and follows a first-order rate law. The products are acetone, isobutene, and H2O. The rate coefficient is expressed by the following Arrhenius equation: log k1(s-1)=(12.53±0.58)-(217.3±8.0) kJ mol-1 (2.303RT)-1. The pyrolytic elimination of this substrate is believed to proceed through a concerted six-membered cyclic transition-state type of mechanism. © 1997 John Wiley & Sons, Inc. Int J Chem Kinet 29: 851-854, 1997
    Additional Material: 6 Tab.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
  • 18
    Electronic Resource
    Electronic Resource
    Steric factors in the gas-phase elimination of esters: The pyrolysis of 2,3-dimethyl-3-pentyl acetate (1977)
    New York, NY : Wiley-Blackwell
    International Journal of Chemical Kinetics 9 (1977), S. 379-385 
    Details
    ISSN: 0538-8066
    Keywords: Chemistry ; Physical Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The kinetics of the thermal decomposition of 2,3-dimethyl-3-pentyl acetate have been studied at a temperature range of 212-260°C and a pressure range of 30-300 mm Hg. The olefins produced are 2-ethyl-3-methyl-1-butene, 3,4-dimethyl-trans-2-pentene, 3,4-dimethyl-cis-2-pentene, and 2,3-dimethyl-2-pentene. The reaction is homogeneous, obeys first-order law, and the value of the rate constant is given by the Arrhenius equation \documentclass{article}\pagestyle{empty}\begin{document}$$ {\rm log}\,k({\rm sec}^{- 1}) = (14.22 \pm 0.23) - (40,600 \pm 500)\,{\rm cal}/{\rm mol}/2.303RT $$\end{document} The directions of elimination and their corresponding partial rates are best explained in terms of purely steric factors.
    Additional Material: 6 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/kin.550090307
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 19
    Electronic Resource
    Electronic Resource
    Substituent effects in the gas-phase eliminations of alpha;-substituted alkyl chlorides the pyrolyses of 2-chloro-3-methylbutane and pinacolyl chloride (1977)
    New York, NY : Wiley-Blackwell
    International Journal of Chemical Kinetics 9 (1977), S. 819-827 
    Details
    ISSN: 0538-8066
    Keywords: Chemistry ; Physical Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The gas-phase pyrolyses of 2-chloro-3-methylbutane and pinacolyl chloride in the temperature range of 345-390°C and pressure range of 60-220 mm Hg are homogeneous and unimolecular in a seasoned reaction vessel. The temperature dependence of the rate constants is given by the Arrhenius equations \documentclass{article}\pagestyle{empty}\begin{document}$$ {\rm log}\,k_{\rm 1} ({\rm sec}^{- 1}) = (13.80 \pm 0.24) - (49,700 \pm 700){\rm cal}/{\rm mol}/2.303RT $$\end{document} and \documentclass{article}\pagestyle{empty}\begin{document}$$ {\rm log}\,k_{\rm 1} ({\rm sec}^{- 1}) = (12.99 \pm 0.09) - (47,200 \pm 250){\rm cal}/{\rm mol}/2.303RT $$\end{document} respectively. The Wagner-Meerwein rearrangement was not observed in these eliminations. Some correlations for the pyrolysis of α-substituted alkyl chlorides are presented and discussed. These facts are consistent with the heterolytic nature of the cyclic transition state mechanisms for these reactions.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/kin.550090512
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 20
    Electronic Resource
    Electronic Resource
    Anchimeric assistance in the gas-phase pyrolysis of β-thiomethylethyl chloride (1978)
    New York, NY : Wiley-Blackwell
    International Journal of Chemical Kinetics 10 (1978), S. 649-652 
    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.550100610
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...