SYNTHESIS, ELECTROCHEMICAL PROPERTIES AND EFFECT OF SUBSTITUENTS ON PI-EXTENDED TCNQ AND DCNQI SYSTEMS

The synthesis of novel pi-extended TCNQ and DCNQI derivatives from the corresponding 1,4-anthraquinones is described. The cyclic voltammetri c data reveal that both TCNQ-type and DCNQI-type acceptors present two one-electron reduction waves to the corresponding anion-radical and d ianion. These novel 2,3-fused TCNQ and DCNQI pi-extended systems are, according to the electrochemical values, better acceptors than the pre viously reported 2,3-5,6-fused TCNQ and DCNQI molecules. A good linear correlation between the first reduction potential of the substituted DCNQI-type derivatives versus the Hammett's sigma3 constant has been f ound.