Anthrylethylene derivatives 1-4 were synthesized to study their photoisomerization. Interestingly 1 and 2 displayed wavelength dependent trans to cis photoisomerization, whose origin is due to preferential light absorption and excitation of the trans isomer. Triplet sensitization studies revealed that these anthrylethylenes undergo only cis to trans isomerization and not trans to cis isomerization. UV-vis absorption, fluorescence emission, ...
