Introduction effects of three electron-withdrawing groups into bis-styrylbenzene skeleton on photoelectric and photophysical properties

Abstract

I synthesized three bis-styrylbenzene derivatives substituted with typical electron-withdrawing groups: E,E-1,4-bis(4-trifluoromethystyryl)benzene (CF3), E,E-1,4-bis(4-cyanostyryl)benzene (CN), and E,E-1,4-bis(4-nitrostyryl)benzene (NO2). The photophysical and photoelectrical properties of these compounds were evaluated in detail. In free molecules in the solution, the intramolecular charge transfer interaction appeared in NO2. In the solid state of CN, the intermolecular charge transfer interaction was observed in its fluorescence spectrum. On the other hand, CF3 did not show intra- and intermolecular charge transfer interactions in either the solid or solution state. The ionization potentials of CF3, CN, and NO2 were −6.52, −6.09, and −6.38 eV, respectively, suggesting that the trifluoromethyl group was most effective for decreasing ionization potentials.