Electrochemistry of conductive polymers - XXV. Electrochemical preparationand characterization of poly(p-phenylenes) from biphenyl and p-terphenyl

Poly(p-phenylene) (PPP) films were prepared by anodic oxidation of biphenyl and p-terphenyl in a rigorously dried dichloromethane solution with 0.10 M tetrabutylammonium tetrafluoroborate as an electrolyte. The polymer growth and film properties were studied using cyclic voltammetry, electrochemical quartz crystal microbalance, infrared spectroscopy, and in situ spectro-el ectrochemical techniques. The results indicate that p-terphenyl is polymeri zed more efficiently than biphenyl and the PPP film prepared from p-terphen yl shows more reversible doping and dedoping properties than that from biph enyl. Electrochemical quartz crystal microbalance studies show that the far adaic efficiencies are much higher for polymerization of p-terphenyl compar ed to that for biphenyl. The infrared spectroscopic measurements for an est imation of chain lengths reveal that PPP is composed of an average of about 7.4 and 8.4 phenyl rings when synthesized from biphenyl and p-terphenyl ox idation, respectively. (C) 2001 The Electrochemical Society.