UNUSUAL BEHAVIOUR OF β-tert-ALKYLSTYRENES IN PHOTOSENSITIZED CIS-TRANS ISOMERIZATION. STRUCTURAL EFFECTS ON TRIPLET ENERGY TRANSFER

Article abstract of DOI:10.1246/cl.1980.261

Photostationary state isomer ratios, rate constants for triplet energy transfer, and quantum yields of isomerization were determined for the triplet sensitized isomerization of β-alkylstyrenes (PhCH=CHR, R = CH3, CH2CH3, CH(CH3)2, C(CH3)3, and C(CH3)2CH2CH3) in benzene.The remarkable high ratio of cis-tert-alkylstyrenes at the photostationary state is mainly attributed to lower rate constants for energy transfer to cis-isomers than to trans-isomers.