The photocyclization of o-vinylbiphenyl to 9,10-dihydrophenanthrene occurs with very low quantum yield because of the low ground-state population of the reactive syn rotamer. 2-Vinyl-1,3-terphenyl exists as a single rotamer which undergoes highly efficient photocyclization. Irradiation at 77 K in a rigid glass permits observation of the 8a,9-dihydrophenanthrene which rearranges to the 9,10-dihydrophenanthrene upon warming of the glass. The barriers for photocyclization and the thermal sigmatropic hydrogen shift are both remarkably small.
|Original language||English (US)|
|Number of pages||2|
|Journal||Journal of the American Chemical Society|
|State||Published - Nov 20 2002|
ASJC Scopus subject areas
- Colloid and Surface Chemistry