Copper(II) sulfide

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Copper(II) sulfide
Other names covellite
Identifiers
CAS number [1317-40-4]
Properties
Molecular formula CuS
Molar mass 95.61 g/mol
Density 4.6 g/mL
Melting point

above 500°C (decomposes [1])
Solubility in water insoluble
Except where noted otherwise, data are given for
materials in their standard state
(at 25 °C, 100 kPa)
Infobox disclaimer and references

Copper(II) sulfide is a chemical compound of copper and sulfur. It occurs in nature as the dark indigo blue mineral covellite. It is a moderate conductor of electricity. [2] A black colloidal precipitate of CuS is formed when hydrogen sulfide, H2S, is bubbled through solutions of Cu(II) salts. [3] It is one of number of binary compounds of copper and sulfur (see copper sulfide). It has attracted interest because of its potential uses in catalysis [4] and photovoltaics[5]

[edit] Structure

The structure of CuS is unusual as it often formulated as CuI2CuIIS2S containing copper in two different oxidation states (+1 and +2) along with sulfide,S2− and disulfide, S22−anions.[3] In the crystal one third of the copper atoms have three near sulfur neighbors at the corners of a triangle and the remainder have four arranged tetrahedrally.[2]. Calculations have shown that the mixed valence structure is less stable than one where the copper atoms have fractional oxidation states[6]. Observations of the 63Cu NMR spectrum [7] indicate two different types of copper atom present although the EPR spectrum is consistent with only one. [8]

[edit] References

  1. ^ Blachnik, R.; Müller A. (October 2000). "The formation of Cu2S from the elements I. Copper used in form of powders". Thermochimica Acta 361 (1-2): 31–52. doi:10.1016/S0040-6031(00)00545-1. 
  2. ^ a b Wells A.F. (1962) Structural Inorganic Chemistry 3d edition Oxford University Press
  3. ^ a b Greenwood, N. N.; Earnshaw, A. (1997). Chemistry of the Elements, 2nd Edition, Oxford:Butterworth-Heinemann. ISBN 0-7506-3365-4. 
  4. ^ Kuchmii, S.Y.; Korzhak A.V., Raevskaya A.E.,Kryukov A.I. (2001). "Catalysis of the Sodium Sulfide Reduction of Methylviologene by CuS Nanoparticles". Theoretical and Experimental Chemistry 37 (1): 36–41. New York: Springer. doi:10.1023/A:1010465823376. 
  5. ^ Mane, R.S.; Lokhande C.D. (June 2000). "Chemical deposition method for metal chalcogenide thin films". Materials Chemistry and Physics 65: 1–31. doi:10.1016/S0254-0584(00)00217-0. 
  6. ^ Tossell, John A. (1978). "Theoretical studies of the electronic structure of copper in tetrahedral and triangular coordination with sulfur". Physics and Chemistry of Minerals 2 (3): 225–236. doi:10.1007/BF00308175. 
  7. ^ Saito, Shin-hachiro; H Kishi, K Nié, and HNakamaru F Wagatsuma and T Shinohara (June 1997). "63Cu NMR studies of copper sulfide". Phys.Rev. B 55: 14527–14535. 
  8. ^ Luther, GW; Theberge SM, Rozan TF, Rickard D, Rowlands CC, Oldroyd A. (Feb 2002). "Aqueous copper sulfide clusters as intermediates during copper sulfide formation.". Environ Sci Technol. 36 (3): 394–402.