Medium-dependent type selectivity in photoreactions of a crown ether-annelated dibenzobarrelene derivative.
[reaction: see text] A concept for modifying the photochemical properties of a dibenzobarrelene derivative by the combination of supramolecular assembly and solid-state photochemistry is presented. The irradiation of dibenzobarrelene 1b and alkali metal complexes thereof (1:1) in acetonitrile or benzene solution leads preferentially to the dibenzocyclooctatetraene 4b as the photoproduct. In contrast, the dibenzosemibullvalene 5b is formed as the main photoproduct in the solid state because of a strong cation effect.
Ihmels
Heiko
H
Institute of Organic Chemistry, University of Würzburg, Am Hubland, Germany. ihmels@chemie.uni-wuerzburg.de
Schneider
Michael
M
Waidelich
Michael
M