Novel conjugated ω,ω′-diaryl hexatriene derivatives with the central double bond in the benzofuran ring and their photochemical and photophysical properties

The trans,trans isomers of 2-[2-(4-methylphenyl)ethenyl]-3-(2-phenylethenyl)benzo[b]furan and four derivatives have been synthesized by a sequence of reactions according to known methods. These new conjugated compounds have been characterized spectrally and photophysically. They practically do not react but decay by radiative relaxation. The high fluorescence quantum yields of these photostable compounds make them interesting as good fluorescent probes. The triplet behaviour of the NO2-derivative has been investigated by laser flash photolysis.