Fluorescent properties and resonance energy transfer of 3,4-bis(2,4-difluorophenyl)-maleimide

A fluorescent compound 3,4-bis(2,4-difluorophenyl)-maleimide from the 3,4-diaryl-substituted maleimides was synthesized and determined to have a Stokes shift of 140 nm (λ(abs) 341 nm, λ(em) 481 nm), a high fluorescent quantum yield (Φ(fl) 0.61) and an extinction coefficient ε((340)) of 48?400 M(-1) cm(-1) in dichloromethane. For the first time we demonstrated the successful implementation of a 3,4-diaryl-substituted maleimide molecule as a donor component in FRET experiments.