Strongly Deformed TCNQ Derivatives: Syntheses and Properties of 7,12-Bis(dicyanomethylene)-7,12-dihydrobenz[a]anthracene (BDCNBA) Derivatives

In spite of large steric repulsion between aromatic quinone moietyand dicyanomethylene moietythe title compounds (BDCNBA) were synthesized by TiCl4-catalyzed reactions of the corresponding aromatic quinonesand malononitrile. BDCNBA showed electronic spectra indicating the intramolecular charge-transfer interaction and redox properties similar to 11,11,12,12-tetracyano-9,10-anthraquinodimethane (TCNAQ) derivatives. BDCNBA showed a low electrical conductivity (≈10−7 Ω−1 cm−1). Strongly deformed structure of BDCNBA was established by X-ray crystallographic analysis.