4096-95-1Relevant articles and documents
An Experimental Approach to the C8H10 Hypersurface. Kinetic and Thermochemical Investigations on a Formally Forbidden Ground-state <2? + 2?) Cycloaddition
Hassenrueck, Karin,Martin, Hans-Dieter,Mayer, Bernhard,Urbanek, Thomas,Zirwes, Thomas,et al.
, p. 177 - 186 (2007/10/02)
The C8H10 hydrocarbons 1, 3, 4, and 6 have been thermolyzed in a static system and the Arrhenius parameters have been obtained.Calorimetric measurements have been carried out to determine the heats of formation.From these data an experimental energy hypersurface is constructed which shows the following remarkable features: 1) The ground-state energy of endo-1 is higher than that of exo-4 by 8 kcal/mol. 2) The predominant reaction pathway of endo-1 is the formally forbidden 6 and 4->3 are the same, the reaction yielding 6 is faster due to a sizeably higher A factor. 4) The tetracycle 3 chooses the microscopic reverse pathway, i.e. its thermolysis proceeds via exo-4 to give the diene 6.