Premium
The cycloaddition of ethylene to butene‐2. II. Energy relations
Author(s) -
Scacchi G.,
Back M. H.
Publication year - 1977
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.550090403
Subject(s) - chemistry , cycloaddition , ethylene , butene , photochemistry , 2 butene , enthalpy , reaction mechanism , catalysis , computational chemistry , organic chemistry , thermodynamics , physics
The rate of the thermal cycloaddition of ethylene to cis ‐and trans ‐butene‐2 has been measured at 663, 678, 693, and 703°K, and the energy relations between the reactants, intermediates, and products have been determined. The intermediate biradicals formed from the cis reactants and from the trans reactants were shown to be separated by a small but measurable enthalpy difference. This result further supports the conclusion of Part I that the intermediates are distinct species which retain some of the original configuration of the reactant. The significance of the results in relation to the mechanism of “forbidden” reactions is discussed.