Kinetic studies of emissive guanine derivatives bearing anthracene moiety

Photoirradiation of methylene-linked anthracene-guanine compounds, which are substituted at the 2 and 9 positions of the anthracene moiety, showed locally excited emission (LE) as well as intramolecular exciplex emission as a result of quenching of the excited singlet state of the anthracene moiety by the guanine moiety. This was confirmed by time-resolved fluorescence as well as steady-state spectroscopy and provides another approach for detecting base-pair formation. Quenching processes by the guanine moiety were investigated by the assumption of equilibrium in the excited state leading to a consistent explanation of the quenching ratio of LE. The quenching rate constant of the excited anthracene moiety by the guanine moiety mainly depends on the intrinsic reduction potential of the anthracene moiety.