Preparation, Properties, and Reduction of a Novel TCNQ-Type Thienoquinoid

TCNQ-type bithienoquinoid condensed with a α-dicarbonyl group was synthesized. The compound revealed a reversible reduction wave at +0.32 V vs SCE. The radical anion species was cleanly generated by a reduction with Na−Hg and characterized:  λ_max = 1027 nm in vis−NIR and a large spin density of the β-carbon atoms on the fused ring by EPR spectroscopy. The radical anion salts were isolated by a reduction with iodide and showed moderate conductivity.