Conducting salts of the new donor bis(ethylenedithio)tetrathionaphthalene (EDNA)

All radical cation-based superconductors are derived from tetrachalcogenafu lvalene precursors. Bis(ethylenedithio)-tetrathionaphthalene (EDNA) was des igned and synthesized as a possible alternative to this limited set of star ting materials. An electrochemical study of EDNA is discussed. The first ra dical cation salts of EDNA are reported. A variety of EDNA:anion stoichiome tries are observed. Four-probe resistivity and room temperature ESR data ar e presented for three (EDNA)(m)(X)(n) salts (X=ClO4, SCN, I-3). (EDNA)ClO4 and (EDNA)(3)(SCN)(2) are semiconductors, but the room temperature resistiv ity of the perchlorate salt is 10(6) greater than that of the thiocyanate s alt. (EDNA)(2)l(3) is metallic to 220 K, where it undergoes a transition to a low activation energy (E-a = 88 meV) semiconductor.