Synthesis and Electrochemical Properties of Porphycene - Diketopyrrolopyrrole Conjugates

The selective iodination of 2,7,12,17-tetrahexylporphycene 1 was successfully accomplished by using N-iodosuccinimide in the presence of activators to give 3-iodoporphycene 2 and 3,13-diiodoporphycene 3a. These iodinated porphycenes can be used as the substrates for palladium-catalyzed coupling to prepare porphycene-diketopyrrolopyrrole conjugates in two steps. The connection of the diketopyrrolopyrrole units to porphycenes broadened their absorption spectra and increased the intensity of the Q-bands due to the electronic interactions between the porphycene and diketopyrrolopyrrole moieties.