SOLID-STATE CONDUCTIVITIES OF CPQ [1,1'-BIS(P-CYANOPHENYL)-4,4'-BIPYRIDILIUM] SALTS, REDOX-STATE MIXTURES AND A NEW INTERVALENCE ADDUCT

The solid-state conductivity, sigma, has been determined for cyanophenyl paraquat (CPQ: 1,1'-bis(p-cyanophenyl)-4, 4'-bipyridilium), for salts containing dication and radical cation redox states and for mixtures of the two. A plot of sigma vs. mole fraction of CPQ+ showed a maximum corresponding to a composition [CPQ2+ (CPQ+)2 (anion-)4], which led to a new solid-state adduct of this stoichiometry, crystallised from a 1 : 2 CpQ2+-CPQ+ solution. The adduct differed spectroscopically from the parent species, and had substantially enhanced conductivity (1.0 X 10(-3) S cm-1). Adduct-like mixtures containing possibly varying proportions of the two CPQ redox states were prepared by reductive precipitation from CPQ2+-containing colloid.