H2PtCl6

Hexachloroplatinic acid, H2PtCl6, also known as chloroplatinic acid or hexachloroplatinic(IV) acid, is a water-soluble platinum complex. In aqueous solution it forms the hexachloroplatinate(IV) anion [PtCl6]2-, with platinum in the +4 oxidation state. The Pt center is coordinated by six chloride ligands in an octahedral geometry. The acid form contains two acidic protons, giving rise to the H2PtCl6 species in solution and in solid hydrates.

Preparation and forms

Hexachloroplatinic acid is typically produced by dissolving platinum metal in aqua regia to form PtCl62- species, followed by acidification to yield H2PtCl6. The compound commonly occurs as hydrates in solid form, for example the hexahydrate H2PtCl6·6H2O. Related salts, such as K2PtCl6, contain the same [PtCl6]2- anion but with different cations.

Properties and applications

H2PtCl6 is a strong source of Pt(IV) chloride complexes and serves as a versatile starting material for inorganic synthesis. It is used to prepare a wide range of platinum(II) and platinum(IV) complexes, and as a precursor for making colloidal platinum catalysts through reduction to Pt(0) nanoparticles. It also features in analytical and electrochemical contexts as a soluble platinum source.

Safety

Hexachloroplatinic acid is corrosive and toxic. It can cause chemical burns and should be handled with appropriate protective equipment in a well-ventilated area, avoiding skin and eye contact and inhalation. Proper disposal in accordance with regulations for heavy metal compounds is required.

See also

K2PtCl6, platinum coordination chemistry, chloroplatinic acid hydrates.