43100 2018 eng 98 105 352 article Elsevier Amsterdam 1 -- -- -- Highly emissive phenanthrene-fused boron–dipyrromethene (PBDP) dyes have been spectroscopically characterized in a series of solvents. The influence of different substituents (-H, -I, -CN, -DMA or a 15C5-crown ether) in the para-position of a phenyl ring attached to the meso-position of the BODIPY core is discussed. This family of dyes has an intense emission at lambda > 630 nm, with fluorescence quantum yields between 0.7 and 1.0 in all solvents studied, except in the case of the dimethylamino-substituted derivative, PBDP-DMA, which undergoes excited-state intramolecular charge transfer (CT), leading to broadband dual fluorescence in highly polar solvents. Introduction of a weaker electron donor such as a benzocrown to the meso-position is not able to trigger a second (charge or electron transfer) process and, interestingly, heavy atom (iodine, PBDP-I derivative) substitution at that moiety does also not have a relevant influence on the photophysics, i.e., enhanced intersystem crossing was not observed. Electrochemical studies of PBDP-DMA complement the data reported and stress the fact that the decrease in fluorescence of PBDP-DMA in highly polar solvents is due to an excited-state CT process rather than to a photoinduced electron transfer (PET). Journal of Photochemistry and Photobiology A: Chemistry 10.1016/j.jphotochem.2017.10.034 1010-6030 04.01.2018 Ana B. Descalzo H.-J. Xu Z. Shen Knut Rurack eng uncontrolled BODIPY dyes eng uncontrolled Charge transfer eng uncontrolled Fluorescence eng uncontrolled Ring fusion Analytische Chemie Verlagsliteratur Datei im Netzwerk der BAM verfügbar ("Closed Access")