Hexacyano-3-radialene anion-radical salts: a promising family of highly soluble p-dopants

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.