ASSOCIATION CONSTANT OF CONDUCTIVE POLY(O-PHENYLENEDIAMINE) WITH HALOGENIDE IONS

An electrically conductive polymer, poly(o-phenylenediamine) (PoPD) wa s found to be soluble in dimethylsulfoxide (DMSO) without any pretreat ment. The PoPD dissolved in the DMSO solution was in an anion-doped st ate, and the cyclic voltammogram of dissolved PoPD obviously showed tw o reversible redox waves. The cyclic voltammograms were measured in DM SO solutions The redox potential shifted with the concentration of the halogenide ion. The relationship between the potential shift and the concentration of the halogenide ion determined the relative associatio n constant of PoPD for four halogenide ions: 104 mol(-1) dm(-3) for F- ; 32 mol(-1) dm(-3) for Cl-; 29 mol(-1) dm(-3) for Br- and 9 mol(-1) d m(-3) for I-.