Electrochemically Polymerized Terthiopehene–C₆₀ Dyads for the Photochemical Generation of Singlet Oxygen

The photoactive layers of poly(terthiophene) with covalently attached fullerene photosensitizers were formed on indium–tin oxide (ITO) substrate in the process of electrochemical polymerization from the solution of corresponding terthiophene–C 60 dyad. Two dyads were studied: without (C 60 TTh) and with (C 60 TThVin) vinyl spacing between C 60 and TTh units. The deposited films [P(C 60 TTh) and P(C 60 TThVin)] were characterized by means of cyclic voltammetry, UV–vis, Raman spectroscopy, and X-ray photoelectron spectroscopy, as well as atomic force microscopy. Both P(C 60 TTh) and P(C 60 TThVin) layers absorbed in visible region and under green light illumination C 60 photosensitizer were activated toward singlet oxygen generation via energy transfer from the polymeric moiety. The formation of 1 O 2 by the layers was confirmed with 2,3,4,5-tetraphenylcyclopentadienone as a specific singlet oxygen quencher. The C 60 –polyterthiophene layers were, in turn, applied in the process of α-terpinene oxidation. It has been shown that the structure of the monomeric TTh–C 60 dyads strongly influences both the electrochemical and the photoactive properties of the electrodeposited layers.