Ultrafast charge transfer and solvation of DNA minor groove binder: Hoechst 33258 in restricted environments

Picosecond resolved photophysical studies on a DNA minor groove binder, H33258 in bulk buffer and various restricted media including DNA reveal twisted intramolecular charge transfer as an important mode of excited state relaxation. A significantly longer component (8.5 ns) in DNA-solvation dynamics associated with δ-relaxation of the DNA is identified.