Gold(I) sulfide is the inorganic compound with the formula Au2S. It is the principal sulfide of gold. It decomposes to gold metal and elemental sulfur, illustrating the "nobility" of gold.

Structure and preparation

The compound crystallizes in the motif seen for cuprous oxide: gold is 2-coordinate, sulfur 4-coordinate, and the S-Au-S linkage is linear.[2] Linear coordination geometry is typical of gold(I) compounds, e.g. the coordination complex chloro(dimethyl sulfide)gold(I). The structure is similar to the α form of silver sulfide (argentite), which only exists at high temperatures.[3]

It can be prepared by treating gold chloride with hydrogen sulfide[4] It also arises by sulfiding dicyanoaurate:

H2S + 2 K[Au(CN)2] → Au2S + 2 KCN + 2 HCN

This product is described as "initially dark reddish-brown" solid that turns "steel-gray".[5][3]

References

  1. ^ Perry, Dale, ed. (1995). Handbook of Inorganic Compounds. p. 184. ISBN 9780849386718.
  2. ^ Wells, A.F. (1984) Structural Inorganic Chemistry, Oxford: Clarendon Press. ISBN 0-19-855370-6.
  3. ^ a b Ishikawa, K. (1995). "Structure and Electrical Properties of Au2S". Solid State Ionics. 79: 60–66. doi:10.1016/0167-2738(95)00030-A.
  4. ^ N. N. Greenwood, A. Earnshaw, Chemistry of the Elements, 2nd ed., Butterworth-Heinemann, Oxford, UK, 1997.
  5. ^ Faltens, Marjorie O. (1970). "Mössbauer Spectroscopy of Gold Compounds". The Journal of Chemical Physics. 53 (11): 4249–4264. Bibcode:1970JChPh..53.4249F. doi:10.1063/1.1673931.