PHOTOCHEMICAL CIS TO TRANS ONE-WAY ISOMERIZATION OF STYRYLAZULENES ONTHEIR TRIPLET EXCITED-STATE - EXAMINATION OF ETHYLENES WITH NON-BENZENOID SUBSTITUENTS OF LOW TRIPLET ENERGIES

Authors
KARATSU T KITAMURA A ARAI T SAKURAGI H TOKUMARU K
Citation
T. Karatsu et al., PHOTOCHEMICAL CIS TO TRANS ONE-WAY ISOMERIZATION OF STYRYLAZULENES ONTHEIR TRIPLET EXCITED-STATE - EXAMINATION OF ETHYLENES WITH NON-BENZENOID SUBSTITUENTS OF LOW TRIPLET ENERGIES, Bulletin of the Chemical Society of Japan, 67(6), 1994, pp. 1674-1679
Citations number
31
Categorie Soggetti
Chemistry
Journal title
Bulletin of the Chemical Society of Japan → ACNP
ISSN journal
00092673
Volume
67
Issue
6
Year of publication
1994
Pages
1674 - 1679
Database
ISI
SICI code
0009-2673(1994)67:6<1674:PCTTOI>2.0.ZU;2-B
Abstract
1-Styrylazulene and 7-isopropyl-1,4-dimethyl-3-styrylazulene (3-styryl guaiazulene) underwent one-way isomerization from the cis to the trans isomer on triplet sensitization. Their triplet states as intermediate s of the isomerization were observed by laser flash photolysis. Howeve r, their excitation to either the lowest excited singlet state (S1) or the second excited singlet state (S2) by direct irradiation afforded photostationary mixtures comprising 98% of the trans and 2% the cis is omers, which implies the participation of a singlet isomerization path .