Twisted intramolecular charge transfer fluorescence in nitro-substituted α,ω-diphenylpolyene compounds

Abstract

A fluorescence study of 1-p-cyanophenyl-4-phenylbuta-1E,3E-diene (2), 1-p-nitrophenyl-4-phenylbuta-1E,3E-diene (3), and 1-p-nitrophenyl-4-p-cyanophenylbuta-1E,3E-diene (4) in solvents of varying polarity at ambient temperature and in a 1:1 ethanol–methanol matrix at 298 and 77 K revealed that the nitro-substituted compounds are capable of exhibiting unusually red-shifted fluorescence emissions due to a twisted intramolecular charge transfer excited state.