Synthesis and properties of optically functionalized polythiophene having porphyrin side-chain

The synthesis and photochemical properties of poly[1,3-bis(dithienyl)benzene] having a porphyrin group as a side-chain were studied. As a target monomer, 1,3-bis(dithienyl)benzene with an ethynylporphyrin substituent was synthesized by Pd-catalyzed cross-coupling reactions. The electrochemical polymerization of the monomer afforded a conductive polymer film on the ITO-coated glass. The spectroelectrochemistry of the polymer was investigated to clarify the electrochemical oxidation behavior. The current density of the target polymer showed a good photoresponse and the much larger photocurrent was observed as compared with the dark current.