Radical cation formation of distyrylarene derivatives via electron beam excitation and photo excitation

Distyrylarene derivatives were synthesized by Witting-Horner reaction and their photophysical properties were examined. They showed large Stokes shift among organic compounds showing the existence of intramolecular charge transfer. By laser flash photolysis and electron beam pulse radiolysis, 1,4-bis(4-nitrostyryl)benzene(BNSB) has T-T absorption at 640 nm, and 9,10-distyrylanthracene (DSA) has T-T absorption at 460 nm. The DSA has another transient absorption at 690 nm whose lifetime is about 100 μs in dichloromethane solution. This absorption is considered as a radical cation produced by the electron transfer from DSA to the solvent. (author)