STERIC EFFECTS ON THE CONTROLLED POTENTIAL ELECTRO-OXIDATION OF 3-METHYLTHIOPHENE AND THIOPHENE OLIGOMERS AND THE PROPERTIES OF THEIR POLYMER-FILMS

This investigation is concerned with the effect of thiophene monomer structures on the electrochemical behavior and physical characteristics of electropolymerized poly(thiophenes) and various poly(3-methylthiophenes). These variations in polymer structure were achieved by employing thiophene and 3-methylthiophene oligomers of different unit sizes and substitution patterns as the starting 'monomers. ' The relative redox characteristics of the 'monomers' were deduced from the measured current maximum values of the electro-oxidation potentials. Electrochemical oxidation of the monomer yields electrically conducting polymers that exhibit internal redox properties unique for each type of starting 'monomer. ' Scanning electron micrographs of the oxidized films are shown.