First Example of Molybdenum Atoms in the Network of High Temperature Chevrel Phases: Moy[Mo6Se8+xSx

Abstract

In the literature Mo6Se8−xSx (0≤x≤4) Chevrel phase binaries are stable compounds, synthesized by solid state reaction from stoichiometric mixture of MoS2, MoSe2, and Mo powders at 1200°C. We report the single-crystal structure of these compounds. The structural determinations show as expected a classical Chevrel phase structure with a framework of pseudomolecular Mo6Se8−xSx cubic units but furthermore exhibit molybdenum atoms in the channels of the host structure of these compounds, leading to the new formula Moy[Mo6Se8−xSx] with 0≤x≤5 and y∼0.3. These extra molybdenum atoms stabilize the Chevrel phase host network and seem to be linking with a molybdenum atom of the Mo6 cluster, forming a kind of Mo7 cluster.