Synthesis, characterization and electrochemical properties of meso-thiocarboxylate-substituted porphyrin derivatives

Considering the versatility of 5,10,15,20-tetrakis(pentafluorophenyl)porphyrin (TPPF 20 ) to react with nucleophiles we highlight here the synthesis and characterization of several mono- and tetra-thiocarboxylate derivatives. The selective displacement of the para-fluorine groups in TPPF 20 by thiocarboxylic acids demonstrates that TPPF 20 is an ideal platform for the rapid formation of thiocarboxylate porphyrins. The optical and electrochemical features of the thiocarboxylate derivatives were also examined thinking on their potential use in photovoltaic devices. From their electrochemical characterization the following parameters were taken into account: (i) electronegative induced effect of the thiocarboxylate dyes owing the presence of the fluorine and sulfur atoms on the molecular structure of the porphyrin; and (ii) the free rotation and flexibility features that such S atom gives to the porphyrin relatively to the semiconductor.