Spectrofluorometric Studies. XI. Some Aspects of the Photochemistry of Ortho-fused Benzocycloalkenes

Abstract

Fluorescent yields of[Formula: see text]excited in the 2500 Å region in cyclohexane solution have been examined. There is a general trend of fluorescent yields decreasing with increasing alkene ring size. The sum of the fluorescent and triplet yields decreases with increasing ring size. Triplet energies, obtained by Evans' method and roughly confirmed by phosphorescent emission spectra at 77 °K, do not vary greatly.

Fluorometric analysis

“…Polarized fluorescence, phosphorescence, and absorption spectra were measured for 1,3-diazaazulene (110). In a series of benzocycloalkanes, the fluorescence yield tended to decrease with ring size (300). A systematic study of emission and absorption of phenylcyclopropanes and phenylethanes at 77 °K showed some unusual features, mechanisms for which were proposed (60).…”