Metal/Semi-Conductivity and Antiferromagnetic Ordering of Fe(III) d Spins in (Benzotetrathiafulvalen othioquinone-1,3-dithio lemethide)(2)-FeBr(4)

摘要

A new donor molecule, benzotetrathiafulval enothioquinone-1,3- dithiolemethide (1) was prepared and electorochemically oxidized in the presence of NEt(4)-MX(4) (M = Fe, Ga; X = Cl, Br) to give its charge transfer (CT) salts with MX(4) ions 1(2)-FeCl(4), 1(2)-GaCl(4), 1(2)-FeBr(4), 1(2)- GaBr(4). These CT salts exhibited considerably higher electrical conductivities of 16-33 S cm-1 at room temperature. Their electrical conducting properties were metallic above 200 K, but below this temperature became semiconducting behavior with very small activation energies of 4-27 meV. Both of the Fe(III) (S = 5/2) d spins of FeCl(4)- and FeBr(4)- ions were subjected to antiferromagnetic interaction, and there was a sign of antiferrromagnetic ordering at around 8 K in the FeBr(4)- salt.