New organic conductors (BEDO-TTF)mMHg(SCN)4

A series of new BEDO-TTF salts with the [Hg(SCN)4]2− anion and Li+, K+, NH4+, Rb+, and Cs+ cations has been prepared. The salts with Li, K, NH4, and Rb show metallic behaviour down to 4 K, the Cs salt behaves as a metal down to 85 K, at lower temperatures a gradual increase of resistance takes place. Crystals of (BEDO-TTF)5[CsHg(SCN)4]2 are triclinic: a=10.436(2), b=10.709(2), c=19.973(4) Å, α=89.59(2), β=81.88(2), γ=72.76(2)°, P1̄, Z=1. The structure of this salt appears as the alternation of BEDO-TTF donor layers of the `I3ʹ type and inorganic layers composed of infinite anion chains incorporating Cs+ cations.