Photophysical properties of porphycene derivatives (18 pi porphyrinoids)

Absorption and fluorescence spectral data and triplet energy content, as well as quantum yields of fluorescence, of triplet state formation, and of sensitized generation of singlet molecular oxygen, O-2((1) Delta(g)), of 38 porphycene derivatives are reported. Long-wavelength absorption and the efficiency of fluorescence and O-2((1) Delta(g)) sensitization qualify most of these porphycenes as potential photodynamic therapy agents (so-called second-generation sensitizers), unless steric or electronic effects by substitution perturb the parent aromatic 18 pi system. (C) 1997 Elsevier Science S.A.