Chromium(III) sulfide

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

$\mathrm{2}\mathrm{C}\mathrm{r}\mathrm{+}\mathrm{3}\mathrm{S}\mathrm{⟶}\mathrm{C}{\mathrm{r}}_{\mathrm{2}}{\mathrm{S}}_{\mathrm{3}}$

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.

See also

• Brezinaite, a mineral with the formula Cr₃S₄