The present work describes an electrochemical method to produce the copolymer poly(2-methoxy-5-bromo-p-phenylenevinylene)/(2,5-dicyano-p-phenylenevinylene) (cop-MB-PPV/DCN-PPV). This copolymer was proposed due to its D-A characteristic produced by the presence of the electron-donating methoxy moiety and the electron-withdrawing dicyano moiety. The copolymer was electrochemically synthetized by cathodic reduction of the convenient starting materials dissolved in a DMF/LiClO4 using a mercury pool acting as working electrode. The copolymer was characterized by infrared (IR), UV-Vis and fluorescence (FL) spectroscopy and cyclic voltammetry (CV). All the results were compared to the MB-PPV homopolymer. The analysis of electrochemical measurements and IR indicated that the cop-MB-PPV/DCN-PPV was obtained through the formation of blocks containing DCN-PPV units linked by blocks containing MB-PPV units. The electronic structure, performed by CV, UV-Vis and FL showed that the conduction band is more stabilized in the copolymer than in homopolymer. Furthermore, the FL spectra indicated that the light emission of the cop-MB-PPV/DCN-PPV in chloroform solution occurs by means of excimer formation.
PPV-like copolymer; donor-acceptor structure; polymeric solar cell; electrochemical polymerization
