Preparative, structural, and physical studies of TTM-TTF complexes with QMNT, a quinone-type acceptor fused with sulfur-containing heterocycles

The 2:3 complex of tetrakis(methylthio)tetrathiafulvalene (TTM-TTF) and the acceptor 5,10-dihydro-5,1-dioxobenzo- [1,2-b:4,5-b′]bis[1,4]dithiin-2,3,7,8-tetracarbonitrile (Qmnt), a p-benzoquinone derivative fused with sulfur-containing heterocycles, was prepared as powder by mixing equi-molar TTM-TTF and Qmnt in hot acetonitrile. Slow evaporation of dilute acetonitrile solution of [TTM-TTF]2[Qmnt]3 yielded needle-like crystals of [TTM-TTF][Qmnt]. The 1:1 complex crystallizes in the triclinic space group P1, with a=7.114(4), b=10.434(3), c=11.305(3) Å, α=106.83(3), β=103.03(3), γ=96.82(3)•, Z=1. The TTM-TTF and Qmnt molecules are stacking alternately along the α axis, with their long molecular axes nearly perpendicular to each other. The room-temperature DC conductivity (compressed pellet) of [TTM-TTF]2[Qmnt]3 is 0.22 S cm−1 with Ea=0.14 eV, and that of [TTM-TTF][Qmnt] is 1.5 × 10−5S cm−1 with Ea=0.36 eV.