Synthesis and properties of alkyl-substituted DTEDT derivatives

Abstract Several derivatives of alkyl-substituted DTEDT have been synthesized. Single crystals of cation radical salts of dimethyl-DTEDT ( 1Ab ) with octahedral anions showed high conductivities ( σ rt = 10 0 –10 1 Scm −1 ) and metal-like behavior around room temperature. The metal to insulator transition temperature tends to decrease as the volume of anions increases. The PF 6 , AsF 6 salts of cyclopenteno-DTEDT ( 1Ac ), and TaF 6 salt of tetramethyl-DTEDT ( 1Bb ) show metallic conducting behavior down to 50 K.