Photophysical and Aggregation Studies of t‐Butyl‐Substituted Zn Phthalocyanines

Three potential photosensitizers for photodynamic therapy: tetra‐ t ‐butyl phthalocyaninato Zn(II), tetrakis‐(1,1‐dimethyl‐2‐phthalimido)ethylphthalocyaninato Zn(II), and tetrakis‐(1,1‐dimethyl‐2‐amino)ethylphthalocyaninato Zn(II), have been studied in homogeneous organic media. Dimerization constants and monomer and dimer spectra have been determined. Fluorescence, triplet and singlet oxygen quantum yìelds were measured and the photo‐physical characterization of the triplet state was performed for the three dyes. These parameters were evaluated in connection with aggregation results.