EIVI Fig. 1. Cyclovoltammograins of 1 and 4. (---):
Voltammogram of 1 embedded in a carbon paste electrode [12] in DMSO/O.l M Bu,NC10,, scan rate 1 mVs-', Ep(red) = -0.20, -0.46, -0.69 V; E,(ox) = -0.15, -0.41, -0.58 V. (--): Solution cyclic voltammogram of 4 in DMSO/O.I M Bu,NCIO, on a 0.07 cm2 Pt disk; scan rate 0.1 Vs-', current scale in this case should be changed to 10.'. Potentials are recorded vs. Ag/AgCI [3]. &(red) = -0.31, -0.55. -0.71 V; โฌ,(OX) = -0.26, -0.48, -0.68 V. carbon paste electrode",] (Fig. 1). The voltammogram is very similar to that of 4. The further positive shift indicates more extended conjugation. The area under the slow sweep voltammogram in Figure 1 corresponds to 1.4 F mol-' for both reduction and oxidation.
Polymer 1 is easily pressed into pellets which have an electrical conductivity['31 of (1.3 0.2) x S cml. Neither the ESR spectrum nor the conductivity change on storage in air for two months. Likewise, 1 is stable in water and in many organic solvents. Exposure of the polymer to iodine vapors increases its conductivity by a factor of 2-3. Gaseous SO, has no effect. Doping experiments in solvent suspensions with I, and FeC1, for the oxidative process, or with Na,S,O, for the reductive process resulted in almost complete loss of conductivity. Thus, it appears that the necessary conditions for conductivity are produced during the dehydration process without the need for additional doping.