High-Pressure Synthesis and Crystal Structure of the Sulfur-Richest Chromium Sulfide CrS3 Composed of Cr(III) and Disulfide Ions.

The new binary chromium sulfide CrS3 has been synthesized by reaction of Cr3S4 and sulfur mixtures at 800 °C and 13 GPa. CrS3 crystallizes in an orthorhombic unit cell with a = 4.6742(7) Å, b = 5.7315(8) Å, c = 10.603(2) Å, and V = 284.873(4) Å3. It has a novel structure composed of Cr2S10 edge-shared octahedral dimers, which share all of their corners to form a three-dimensional structure. All of the sulfur atoms form S22- disulfide ions with a S-S distance of 2.063(5) or 2.068(8) Å. The structure of CrS3 is a derivative of the crystal structure of marcasite FeS2, in which one in three metal sites of the marcasite structure is vacant in the CrS3 structure.