Intramolecular benzene excimer formation in 13,14-diphenyldibenzo[b,j][4,7]phenanthroline

13,14-diphenyldibenzo[b,j][4,7]phenanthroline (DBP3) in various solvents was studied by time-resolved fluorescence and fs transient absorption (fs-TA) spectroscopy. An intramolecular benzene excimer is demonstrated to form within DBP3; it exhibits strong redshifted emission with maximum at 540–640 nm. “Intrinsic” fluorescence from DBP3 is dramatically quenched down to τ = 50–400 fs in all the solvents studied. Fs-TA and time-resolved fluorescence spectra have proved that relaxed intramolecular benzene excimer is formed from S1 state via hot excimer state with three lifetime components: 50 fs, ∼3.5 ps, and ∼25 ps, which are of the inertial (electronic) and diffusive parts of the relaxation due to solute–solvent interaction. Formation of triplet states via intersystem crossing was observed directly from the upper excited electronic states of DBP3.