14993-07-8Relevant articles and documents
Schneider,Csacsko
, p. 330 (1977)
Organic Photochemistry with 6.7-eV Photons: Photoisomerization of Tricyclo2,4>oct-6-ene (Endo and Exo) and Tricyclo2,4>non-6-ene (Endo and Exo)
Srinivasan, R.,Ors, Jose A.,Brown, Karen H.,Baum, Thomas,White, Lloyd S.,Rossi, Angelo R.
, p. 5297 - 5302 (2007/10/02)
Photolysis of the title compounds at 185 nm in solution leads to internal addition of the olefinic group to the cyclopropane ring and cleavage of the cyclopropane to a bicyclic 1,4-diene.A theoretical analysis of the interactions between the ?-orbitals of the double bond and the ? orbitals of the cyclopropane in each of these compounds has been carried out.The effect of through-bond interactions superimposed upon the through-space effects when extended to the valence excited states gives rise to three low-lying excited states which are (in order to decreasing energy) ?A -> ?A* + ?* (forbidden), ?S + ? -> ?* - ?A* (allowed), and ? - ?S -> ?* + ?A* (allowed).The internal addition reaction is identified with the ? - ?S -> ?* + ?A* state and the cleavage of the cyclopropane to yield a 1,4-diene with the ?S + ? -> ?* + ?A* state.The low reactivity of the endo-tricyclo2,4>non-6-ene is believed to relate to a departure from the ordering of the excited states as described above.
