Chromium(III) sulfide explained

Chromium(III) sulfide is the inorganic compound with the formula Cr₂S₃. It is a brown-black solid. Chromium sulfides are usually nonstoichiometric compounds, with formulas ranging from CrS to Cr_0.67S (corresponding to Cr₂S₃).

Preparation

Chromium(III) sulfide can be prepared through the reaction of a stoichiometric mixture of the elements at 1000 °C^[1]

2 Cr+3 S\longrightarrowCr _{2S} _{3}

It is a solid that is insoluble in water. According to X-ray crystallography, its structure is a combination of that of nickel arsenide (1:1 stoichiometry) and Cd(OH)₂ (1:2 stoichiometry). Some metal-metal bonding is indicated by the short Cr-Cr distance of 2.78 Å.^[2]

See also

• Brezinaite, a mineral with the formula Cr₃S₄

Notes and References

1. Georg Brauer: Handbuch der präparativen anorganischen Chemie. 3., umgearb. Auflage. Band III. Enke, Stuttgart 1981,, S. 1493
2. Jellinek, F. "The structures of the Chromium Sulphides" Acta Crystallographica 1957, volume 10, p620-p628