Absorption and fluorescence (insets) spectra of H2TBP (1, A) (H2TBP was first dissolved in pyridine, and a drop of this solution was added to toluene.), H2Ph2TBP (2, B), H2Ph4TBP (3, C) and H2TCHP(CO2Bu)8 (4, D), H2Ph2TCHP (5, E) and H2Ph4TCHP (6, F) (Small amount of TMEDA was added to prevent dication formation.) in toluene at 295 K.