Anthracene derivatives Q 1080Wavelength Dependent Regioselective E→Z Isomerization of 9-Anthryldiene Derivatives. -9-Substituted anthryldiene derivatives (I) undergo a highly efficient and regioselective E→Z isomerization upon direct excitation using >400 nm light to afford (2E,4Z)-isomer (II). A change in the product distribution is observed by changing the wavelength. -(REDDY, M. J. R.; KUMAR, P. A.; SRINIVAS, U.; REDDY, V. V.; REDDY, M. J. R.; RAO, G. V.; RAO*, V. J.; Indian J. Chem., Sect. B: Org. Chem.

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Organic chemistryOrganic chemistry Z 0200 Regioselective E(trans)-Z(cis) Photoisomerization in Naphthyldiene Derivatives-[28 refs.]. -(REDDY, M. J. R.; REDDY, V. V.; SRINIVAS, U.; REDDY, M. J. R.; RAO*, V.

We have synthesized several 3‐arylallyl acetates 1, 2, 3, 5 and 6, and E‐3‐(1‐naphthyl)‐2‐propene‐1‐ol 4 for studying ionic photodissociation. Compounds 1, 2 and 3 underwent an efficient ionic photodissociation in polar solvents like acetonitrile and methanol leading to the formation of rearranged acetate and methyl ether products, as well as undergoing an E–Z isomerization. The arylallyl alcohol 4 and the two arylallyl acetates 5 and 6 did not undergo ionic photodissociation. Quantum yields of product formation, quantum yields of fluorescence, solvent polarity effects and triplet‐sensitization studies indicated that a highly polarized excited singlet state is responsible for the ionic photodissociation. Both the singlet‐ and triplet‐excited states are effective in displaying E–Z isomerization in 1, 2, 3 and 4. Compounds 5 and 6 are highly fluorescent, and the fluorescence may be the excited state deactivation pathway along with internal conversion.