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Kinetics, mechanism, and endo selectivity of Diels–Alder reactions of alkylmonosubstituted ethenes with cyclohexa‐1,3‐diene in the gas phase
Author(s) -
Huybrechts G.,
Poppelsdorf H.,
Maesschalck L.,
Van Mele B.
Publication year - 1984
Publication title -
international journal of chemical kinetics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.341
H-Index - 68
eISSN - 1097-4601
pISSN - 0538-8066
DOI - 10.1002/kin.550160202
Subject(s) - chemistry , arrhenius equation , selectivity , reagent , torr , reaction rate constant , diene , gas phase , kinetics , homogeneous , medicinal chemistry , phase (matter) , photochemistry , stereochemistry , organic chemistry , activation energy , thermodynamics , catalysis , physics , natural rubber , quantum mechanics
The reactionswhere Y = CH 3 (M), C 2 H 5 (E), i C 3 H 7 (I), and t C 4 H 9 (T) have been studied between 488 and 606 K. The pressures of CHD ranged from 16 to 124 torr and those of YE from 57 to 625 torr. These reactions are homogeneous and first order with respect to each reagent. The rate constants (in L/mol·s) are given by\documentclass{article}\pagestyle{empty}\begin{document}$$ {\rm log}_{{\rm 10}} k_{{\rm NMBO}} = - {{\left( {26530 \pm 80} \right)} \mathord{\left/ {\vphantom {{\left( {26530 \pm 80} \right)} {4.576T + \left( {6.05 \pm 0.03} \right)}}} \right. \kern-\nulldelimiterspace} {4.576T + \left( {6.05 \pm 0.03} \right)}} $$\end{document}\documentclass{article}\pagestyle{empty}\begin{document}$$ {\rm log}_{{\rm 10}} k_{{\rm XMBO}} = - {{\left( {28910 \pm 130} \right)} \mathord{\left/ {\vphantom {{\left( {28910 \pm 130} \right)} {4.576T + \left( {6.32 \pm 0.05} \right)}}} \right. \kern-\nulldelimiterspace} {4.576T + \left( {6.32 \pm 0.05} \right)}} $$\end{document}\documentclass{article}\pagestyle{empty}\begin{document}$$ {\rm log}_{{\rm 10}} k_{{\rm NEBO}} = - {{\left( {26150 \pm 120} \right)} \mathord{\left/ {\vphantom {{\left( {26150 \pm 120} \right)} {4.576T + \left( {5.85 \pm 0.05} \right)}}} \right. \kern-\nulldelimiterspace} {4.576T + \left( {5.85 \pm 0.05} \right)}} $$\end{document}\documentclass{article}\pagestyle{empty}\begin{document}$$ {\rm log}_{{\rm 10}} k_{{\rm XEBO}} = - {{\left( {28560 \pm 120} \right)} \mathord{\left/ {\vphantom {{\left( {28560 \pm 120} \right)} {4.576T + \left( {6.07 \pm 0.05} \right)}}} \right. \kern-\nulldelimiterspace} {4.576T + \left( {6.07 \pm 0.05} \right)}} $$\end{document}\documentclass{article}\pagestyle{empty}\begin{document}$$ {\rm log}_{{\rm 10}} k_{{\rm NIBO}} = - {{\left( {26560 \pm 80} \right)} \mathord{\left/ {\vphantom {{\left( {26560 \pm 80} \right)} {4.576T + \left( {5.57 \pm 0.03} \right)}}} \right. \kern-\nulldelimiterspace} {4.576T + \left( {5.57 \pm 0.03} \right)}} $$\end{document}\documentclass{article}\pagestyle{empty}\begin{document}$$ {\rm log}_{{\rm 10}} k_{{\rm XIBO}} = - {{\left( {28350 \pm 100} \right)} \mathord{\left/ {\vphantom {{\left( {28350 \pm 100} \right)} {4.576T + \left( {5.47 \pm 0.04} \right)}}} \right. \kern-\nulldelimiterspace} {4.576T + \left( {5.47 \pm 0.04} \right)}} $$\end{document}\documentclass{article}\pagestyle{empty}\begin{document}$$ {\rm log}_{{\rm 10}} k_{{\rm NTBO}} = - {{\left( {28920 \pm 50} \right)} \mathord{\left/ {\vphantom {{\left( {28920 \pm 50} \right)} {4.576T + \left( {5.86 \pm 0.02} \right)}}} \right. \kern-\nulldelimiterspace} {4.576T + \left( {5.86 \pm 0.02} \right)}} $$\end{document}\documentclass{article}\pagestyle{empty}\begin{document}$$ {\rm log}_{{\rm 10}} k_{{\rm XTBO}} = - {{\left( {32890 \pm 120} \right)} \mathord{\left/ {\vphantom {{\left( {32890 \pm 120} \right)} {4.576T + \left( {6.19 \pm 0.05} \right)}}} \right. \kern-\nulldelimiterspace} {4.576T + \left( {6.19 \pm 0.05} \right)}} $$\end{document}The Arrhenius parameters are used as a test for a biradical mechanism and to discuss the endo selectivity of the reactions.