Conductive and magnetic properties of 3,4-dimethoxy- and 3,4-ethylenedioxy-capped polypyrrole and polythiophene

Electrochemically prepared poly(3,4-dimethoxypyrrole), poly(3,4-dimethoxyth iophene), poly(3,4-ethylenedioxypyrrole), and poly(3,4-ethylenedioxythiophe ne) have been characterized by cyclic voltammetry (CV) and ultraviolet-visi ble (UV-vis) and Fourier transform infrared (FTIR) spectroscopy and were su bsequently investigated by in situ conductivity, in situ electron spin reso nance spectroscopy (ESR), and electrochemical quartz crystal microbalance ( EQCM) analysis. Blocking the 3 and 4 positions of the heteroaromatic ring a llows the display of a complete potential window of conductivity far the po lypyrroles during the oxidative doping process, whereas a potential window of conductivity wider than usual, but still open, is displayed for the poly thiophenes. The combination of redox-type conduction and solvation in poly( 3,4-dimethoxypyrrole) gives this material unusual solvatoconductive propert ies.