Porphins fluorescence spectra

Figure 10.30 shows the absorption and fluorescence spectra of 5,10,15,20-tetraphenyl-21H,23H-porphine (TPP).17 The chemical structure of TPP is inset. The porphyrin Soret band is seen as a strong, narrow absorption peak at 418 nm. The weaker absorption peaks at 512 and 550 nm are the Q bands, also typical of porphyrins. The fluorescence spectrum has peaks at 653 and 714 nm and the fluorescence quantum yield has been measured to be 11 % in solution exposed to air.66 The Soret absorption band has strong overlap with the fluorescence spectrum of PFO, resulting in efficient Forster transfer. The Forster-transfer radius has been calculated from the relative overlap of these spectra to be 4.8 nm. 

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