Reduction Potentials: Key to Doping Phenomena In Polyacetylene, (Ch)X

Abstract When (CH)X is p-doped (oxidized) or n-doped (reduced) chemically or electrochemically the “dopant” ion may or may not be derived from the oxidizing or reducing agent as dictated by the nature of the specific doping reaction involved. The reduction potentials of neutral (CH)X and its various oxidized or reduced states have been determined electrochemically and have been used, together with known standard reduction potentials of a variety of redox couples, to rationalize the doping of (CH)X to the metallic regime by a number of dopant species, including gaseous O2 or benzoquinone (both in aqueous HBF4 solution), aqueous HClO4 and aqueous H2SO4. Reduction potentials can be used to predict new p- or n-dopants which are thermodynamically capable of doping (CH)X to the metallic regime. The p-doped polyacetylene is remarkably stable in the aqueous solutions in which it is synthesized.