THE STRUCTURE OF 5-MEMBERED POLY-HETEROCYCLES

Thin films of Poly-N-Methylpyrrole (PNMePy), Poly-3-Methylthiophene (P 3MeTh), and Poly-Bithiophene (PBiTh) are electrochemically formed on g old- and palladium-electrodes. During oxidation, which switches the co nductivity of the polymer from an insulating state to metallic conduct ion, anions are intercalated in the polymer to neutralize the positive charge on the polymer backbone. The electrochemical quartz micro bala nce allows comparison of the coulometric data with the mass of anions intercalated during this process. A small amount of solvent is additio nally incorporated during this process. Mechanical stress within the f ilm causes a visible bending of the electrode. Ionic and electronic re sistances are parallel and the lower value determines the reaction sit e. The polymer films have a high ionic conductivity necessary for hydr ogen and oxygen evolution at the substrate surface underneath the poly mer film. Electron transfer reactions yield data of the resistance and the pore size of the polymer.