Mercury sulfide Mercury sulfide Mercury sulfide, mercuric sulfide, mercury sulphide, or mercury(II) sulfide is a chemical compound composed of the chemical elements mercury and sulfur. It is represented by the chemical formula HgS. It is virtually insoluble in water. HgS is dimorphic with two crystal forms: Crystals of red, α-HgS, are optically active. This is caused by the Hg-S helices in the structure. β-HgS is precipitated as a black powder when HS is bubbled through solutions of Hg(II) salts. β-HgS is unreactive to all but concentrated acids. Mercury metal is produced from the cinnabar ore by roasting in air and condensing the
Metal ammine complex is ammonia (pK ~ 33). For highly cationic complexes such as [Pt(NH)], the conjugate base can be obtained. The deprotonation of cobalt(III) ammine-halide complexes, e.g. [CoCl(NH)] labilises the Co-Cl bond, according to the Sn1CB mechanism. Metal ammine complexes find many uses. Cisplatin (PtCl(NH)) is a coordination compound containing two chloro and two ammine ligands. This is a drug used in treating cancer. Many other amine complexes of the platinum group metals have been evaluated for this application. In the separation of the individual platinum metals from their ore, several schemes rely on the precipitation of [RhCl(NH)]Cl. In some separation schemes,