[en] Two novel monofullerene-bis(pyropheophorbide a) complexes were synthesized and their photophysical properties were studied by using both steady-state and time-resolved techniques. It was revealed that in the pyropheophorbide a (pyroPheo)-C₆₀ molecular system (FP1) strong quenching of the first excited singlet state of the pyroPheo and, as result, dramatically decreasing of photosensitized singlet oxygen generation occurs by efficient photoinduced electron transfer to the fullerene molecule with a rate constant of 2.5 x 10⁹ s^-1. In contrast, the fullerene hexaadduct-bis(pyroPheo) system (FHP1), which possesses five diethyl malonate addends in the remaining octahedral positions, shows a high singlet oxygen quantum yield which is due to the reduced fullerene chromophore which is not a good electron acceptor anymore

[en] Spectral and kinetic characteristics of thermally activated delayed fluorescence (TADF) and phosphorescence of acriflavine in polyvinylalcohol films have been investigated. It was shown that TADF and phosphorescence decay times decrease due to fluorescence resonance energy transfer (FRET) as the concentration of the dye molecules increases. The luminescence spectra of the concentrated solutions are bathochromic shifted with respect to that of the deluted ones. Moreover, TADF and phosphorescence spectra of the concentrated solutions shift to the higher frequency region as emission decays. These effects are determined by the correlation between FRET direction and the heterogeneity of the triplet state lifetimes. Numerical simulations of the spectral and kinetic characteristics of TADF and phosphorescence were made by means of Monte-Carlo integrations, and results were compared with experimental data