) and (ε = 22.9 10 3 M -1 cm -1 ), respectively. Considering the moderate absorptivity and low energy of this band, we assign it to the SRCT absorption of the ring system (S1 a Photoluminescence quantum yield of degassed and aerated solutions. b Prompt decay lifetime of emission, λexc = 375 nm. No delayed lifetimes were detected for any of the emitters. All spectra were obtained in optically dilute solutions (~10 -5 M). See Table for full absorption data.