Sg. Hong et al., A STUDY OF THERMAL DIELS-ALDER REACTION O F ETHENE WITH CYCLOHEXA-1,3-DIENE BY USING AM1 METHOD, Gaodeng xuexiao huaxue xuebao, 17(8), 1996, pp. 1277-1279
UHF/AM1 molecular orbital method has been employed to study the therma
l Diels-Alder reaction of ethene with cyclohexa-1,3-diene, The results
showed that this reaction is exothermal, and it has two competitive r
outes; the activation energy of the concerted process is 112.667 kJ/mo
l, and that of the rate-determining step of the biradical pathway is 7
8.406 kJ/mol, the biradical process has lower activation energy than t
he concerted one.