ISOMERIZATIONS OF C8H8-DOT - EXPERIMENTS AND CALCULATIONS IN SYNERGY(CENTER)

This contribution describes the elucidation of two consecutive phototr ansformations of the radical cation of cyclooctatetraene (COT.(+)) whi ch were first noted by Shida and Iwata in 1972 from changes in the opt ical spectra. Here we highlight some particular features of the electr onic and molecular structure of the involved species. In addition to a spects which were already discussed in our original publications on th e subject (cf. [4-7]), we focus on the question of localized versus de localized structures for the primary photoproduct of COT.(+), i.e. the radical cation of bicyclo[3.3.0]octa-2,6-diene-4,8-diyl (BOD.(+)). Di fferent factors which favor one or the other structure are identified and quantified. (C) 1997 Elsevier Science B.V. [GRAPHICS]