Chemical elements
    Physical Properties
    Chemical Properties
      Aurous fluoride
      Aurous chloride
      Aurous bromide
      Aurous iodide
      Aurous oxide
      Aurous sulphide
      Aurous thiosulphate
      Aurous Derivatives of Nitrogen
      Aurous cyanide
      Potassium aurothiocyanate
      Ammonia and Aurous Halides
      Gold dichloride
      Gold dibromide
      Gold monoxide
      Gold monosulphide
      Gold monosulphate
      Nitride of Bivalent Gold
      Auric chloride
      Aurichloric Acid
      Auric bromide
      Auribromic Acid
      Auric iodide
      Auri-iodic Acid
      Auric iodate
      Auric hydroxide
      Auric sulphide
      Auric sulphate
      Acid auryl sulphate
      Auric selenide
      Auric selenate
      Auric telluride
      Gold and Nitrogen
      Auric nitrates
      Gold and Phosphorus
      Gold arsenides
      Auric selenide
      Auric antimonide
      Auric cyanide
      Salts of Auricyanic Acid
      Double Salts of Auric thiocyanate
      Gold carbide
      Gold and Silicon
    PDB 1a52-4acl

Aurous cyanide, AuCN

The cyanide is produced by the interaction of hydrogen cyanide and auric hydroxide; by double decomposition from auric chloride and mercuric cyanide, with simultaneous production of complex derivatives; and by the decomposition of auric cyanide, as well as by the action of hydrochloric acid on its complex salts at 50° C.:


Aurous cyanide forms yellow, microscopic laminae, very slightly soluble in water. It is more stable than aurous iodide, but at red heat is decomposed into gold and cyanogen. Its insolubility renders it immune to the action of dilute acids and hydrogen sulphide, but solutions of ammonia, potassium hydroxide, ammonium sulphide, and sodium thiosulphate dissolve it, probably forming complex derivatives. In aurous cyanide the tendency to form complex compounds is much more marked than in the corresponding chloride, bromide, and iodide. Its interaction with potassium ferrocyanide has been studied by Beutel.

A solution of potassium cyanide dissolves aurous cyanide, and also finely divided gold in presence of air, forming potassium aurocyanide, KAu(CN)2, a substance also produced by anodic solution of gold in a solution of potassium cyanide. The anhydrous salt crystallizes from water in colourless, rhombic octahedra. At ordinary temperatures its solubility is 11.66 grams in 100 grams of water. Its solution absorbs chlorine, bromine, and iodine, forming complex halogen derivatives, containing ions of the type .

Double decomposition of ammonium sulphate and potassium aurocyanide yields ammonium aurocyanide, NH4Au(CN)2. This substance begins to decompose at 100° C. into aurous cyanide, hydrogen cyanide, and ammonia. Sodium aurocyanide, NaAu(CN)2, resembles the corresponding potassium salt in both preparation and properties. Salts of the aurocyanic radical, Au(CN)2', with other metals are also known. The compound HAu(CN)2 has not been isolated, since it decomposes readily with production of hydrogen cyanide.

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