Crystal structure and physical properties of a magnetic molecular conductor (EDO-TTFVODS)2FeCl4

Abstract Crystal structure, and electrical conducting and magnetic properties of a radical cation salt of EDO-TTFVODS with magnetic FeCl 4 − ion, (EDO-TTFVODS) 2 FeCl 4 (EDO-TTFVODS = ethylenedioxytetrathiafulvalenoquinone-1,3-diselenolemethide) are reported. In this salt, there are two independent donor molecules formed two different layers A and B, and the counter FeCl 4 − ions layer is sandwiched between two donor layers A and B along the b -axis. The donor molecules form the one-dimensional columns along the a -axis in both donor layers. This salt shows high conductivity at room temperature ( σ RT  = 25 S cm −1 ) and a metallic behavior down to ca. 80 K, where a metal–insulator transition however occurs. The magnetic susceptibility obeys a Curie–Weiss law (Curie constant C  = 4.42 emu K mol −1 and Weiss temperature Θ  = −1.5 K), without any magnetic ordering down to 1.8 K. This result suggests the weak antiferromagnetic interaction between the d spins of FeCl 4 − ions.