Synthesis, Structure, and Electrical Properties of the Mo12 Cluster Sulfide Hg∼2.8KMo12S14 Containing Mercury Chains

The new compound Hg∼2.8KMo12S14 was synthesized by diffusing mercury into the metastable KMo12S14 compound at 350 °C. Its crystallographic structure, solved from single-crystal X-ray diffraction, shows that the Mo–S framework is maintained during the synthesis. It is based on Mo12S14S6 units interlinked via Mo–S bonds as in the parent compound. The mercury forms linear chains with Hg–Hg distances of about 2.72 Å in the tunnels delimited by the Mo12S14S6 units. Superconductivity was observed below 2.5 K by electrical resistivity and magnetic susceptibility measurements.