SzcmmaryThe electrochemical polymerization of pyrrole on platinum produces a strongly adhered, durable film with enhanced conductivity and good electrode properties.MANY workers have been interested in the modification of electrode surfaces by covalently attaching organic monolayers or depositing polymer films.1 While the electrochemical preparation of films on a surface could conceivably produce superior material, this approach has not been pursued rigorously. Our interest in the preparation of durable, conducting organic electrode surfaces led us to this approach. We now present the preliminary results on the electrochemical polymerization of pyrrole2 under controlled conditions. The polypyrrole films were synthesized galvanostatically on a platinum surface in a two-electrode cell containing 0-1 M Et4NBF4 and 0.06 M pyrrole in 99% aqueous MeCN. The films strongly adhere to the surface. These films can be prepared in a variety of aprotic solvents. The yield of deposited film is 0-5 mol F-1 but can be less if the nucleophilic character of the solvent or electrolyte is enhanced. For example, no film is produced in the presence of 0-1 M Et4NBr in MeCN.A polypyrrole film (0.8,um thick) on platinum was used as an electrode in cyclic voltammetry measurements. In MeCN and Me,SO containing Et4NBF,, only a broad background current is observed in the range + 1.0 to -2.0 V.The voltammogram of M ferrocene in MeCN resembles that obtained on platinum. The E" value equals $0.450 us. NaCE (sodium chloride calomel electrode) (0.450 V on Pt3), ip,/ipa equals unity, and I Ep, --E.pcI equals 90 mV a t 2OmVs-l scan rate, with ca. 70% zR compensationFor the reduction of tetracyanoquinodimethane (TCNQ) the signals appear a t +0.260 and -0-290 V vs. NaCE (+0-265 and -0.300 V on Pt). I values equal 70mV a t 2OmVs-l scan rate and ipa/zpc values equal unity for both reaction steps.The I E,, --E PC

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