2[Co(NH3)5Cl]Cl2 + 2H2S CoS2 + CoCl2 + 4NH4Cl + 6NH3
Chloridopentaamminecobalt(III) chloride react with hydrogen sulfide to produce cobalt(II) persulfide, cobalt(II) chloride, ammonium chloride and ammonia. This reaction takes place at a temperature near 630°C.