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 cyanophen yl paraquat (CPQ: 1,1'-bis(p-cyanophenyl)-4, 4'-bipyridilium), for sal ts containing dication and radical cation redox states and for mixture s of the two. A plot of sigma vs. mole fraction of CPQ+ showed a maxim um 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 fro m the parent species, and had substantially enhanced conductivity (1.0 X 10(-3) S cm-1). Adduct-like mixtures containing possibly varying pr oportions of the two CPQ redox states were prepared by reductive preci pitation from CPQ2+-containing colloid.