Organic and inorganic salts of the hexacyano-[3]-radialene anion-radical are readily available and thermally stable compounds (up to ∼180 °C). The tetrabutylammonium salt exhibits an extremely high solubility in a range of solvents (>300 mg l^-1 in CHCl₃) and acts as an efficient p-dopant for poly(3-hexylthiophene) to provide composite films with a conductivity above 2 S cm^-1.