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Copper monosulfide

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Copper monosulfide
Names
IUPAC name
Copper sulfide
Other names
Covellite
Copper(II) sulfide
Cupric sulfide
Identifiers
3D model (JSmol)
ChemSpider
ECHA InfoCard 100.013.884 Edit this at Wikidata
RTECS number
  • GL8912000
  • InChI=1S/Cu.S checkY
    Key: BWFPGXWASODCHM-UHFFFAOYSA-N checkY
  • InChI=1/Cu.S/rCuS/c1-2
    Key: BWFPGXWASODCHM-BLKBWTQCAT
  • [Cu]=S
Properties
CuS
Molar mass 95.611 g/mol
Density 4.6 g/cm3
Melting point above 500°C
insoluble
1.27 x 10-36
Solubility soluble in HNO3, NH4OH, KCN
soluble in HCl, H2SO4
1.45 [1]
Related compounds
Other anions
 Copper(II) oxide
Other cations
 zinc sulfide
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
checkY verify (what is checkY☒N ?)

Copper monosulfide 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. [3] A black colloidal precipitate of CuS is formed when hydrogen sulfide, H2S, is bubbled through solutions of Cu(II) salts.[4] It is one of a number of binary compounds of copper and sulfur (see copper sulfide for an overview of this subject), and has attracted interest because of its potential uses in catalysis[5] and photovoltaics.[6]

CuS structure and bonding

Copper monosulfide crystallizes in the hexagonal crystal system, and this is the form of the mineral covellite. There is also an amorphous high pressure form [7] which on the basis of the Raman spectrum has been described as having a distorted covellite structure. An amorphous room temperature semiconducting form produced by the reaction of a Cu(II) ethylenediamine complex with thiourea has been reported, which transforms to the crystalline covellite form at 30 °C.[8]
The crystal structure of covellite has been reported several times,[9][10][11] and whilst these studies are in general agreement on assigning the space group P63/mmc there are small discrepancies in bond lengths and angles between them. The structure was described as "extraordinary" by Wells[12] and is quite different from copper(II) oxide, but similar to CuSe (klockmannite). The covellite unit cell contains 6 formula units (12 atoms)in which:

  • 4 Cu atoms have tetrahedral coordination (see illustration).
  • 2 Cu atoms have trigonal planar coordination (see illustration).
  • 2 pairs of S atoms are only 207.1 pm apart [11] indicating the existence of an S-S bond (a disulfide unit).
  • the 2 remaining S atoms form trigonal planar triangles around the copper atoms, and are surrounded by five Cu atoms in a pentagonal bipyramid (see illustration).
  • The S atoms at each end of a disulfide unit are tetrahedrally coordinated to 3 tetrahedrally coordinated Cu atoms and the other S atom in the disulfide unit (see illustration).

The formulation of copper monosulfide as CuIIS (i.e. containing no sulfur-sulfur bond) is clearly incompatible with the crystal structure, and also at variance with the observed diamagnetism [13] as a Cu(II) compound would have a d9 configuration and be expected to be paramagnetic.[4]
Studies using XPS[14][15][16][17] indicate that all of the copper atoms have an oxidation state of +1. This contradicts a formulation based on the crystal structure and obeying the octet rule that is found in many textbooks (e.g. [4][18]) describing CuS as containing both CuI and CuII i.e. (Cu+)2Cu2+(S2)2–S2–. An alternative formulation as (Cu+)3(S2–)(S2)– was proposed and supported by calculations.[19] The formulation should not be interpreted as containing radical anion, but rather that there is a delocalized valence "hole". [19][20] Electron paramagnetic resonance studies on the precipitation of Cu(II) salts indicates that the reduction of Cu(II) to Cu(I) occurs in solution. [21]

ball-and-stick model of part of
the crystal structure of covellite
trigonal planar
coordination of copper
tetrahedral
coordination of copper
trigonal bipyramidal
coordination of sulfur
tetrahedral
coordination of sulfur-note disulfide unit

See also

References

  1. ^ Pradyot Patnaik. Handbook of Inorganic Chemicals. McGraw-Hill, 2002, ISBN 0070494398
  2. ^ Blachnik, R. (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. {{cite journal}}: Unknown parameter |coauthors= ignored (|author= suggested) (help)
  3. ^ Wells A.F. (1962) Structural Inorganic Chemistry 3d edition Oxford University Press
  4. ^ a b c Greenwood, Norman N.; Earnshaw, Alan (1997). Chemistry of the Elements (2nd ed.). Butterworth-Heinemann. ISBN 978-0-08-037941-8.
  5. ^ Kuchmii, S.Y. (2001). "Catalysis of the Sodium Sulfide Reduction of Methylviologene by CuS Nanoparticles". Theoretical and Experimental Chemistry. 37 (1). New York: Springer: 36–41. doi:10.1023/A:1010465823376. {{cite journal}}: Unknown parameter |coauthors= ignored (|author= suggested) (help)
  6. ^ Mane, R.S. (2000). "Chemical deposition method for metal chalcogenide thin films". Materials Chemistry and Physics. 65 (1): 1–31. doi:10.1016/S0254-0584(00)00217-0. {{cite journal}}: Unknown parameter |coauthors= ignored (|author= suggested) (help); Unknown parameter |month= ignored (help)
  7. ^ Peiris, M (1996). "Pressure-induced amorphization of covellite, CuS". J. Chem. Phys. 104 (1): 11–16. doi:10.1063/1.470870. {{cite journal}}: Unknown parameter |coauthors= ignored (|author= suggested) (help)
  8. ^ Grijalva, H. (1996). "Amorphous and crystalline copper sulfides, CuS". J. Mater. Chem. 6 (7): 1157–1160. doi:10.1039/JM9960601157. {{cite journal}}: Unknown parameter |coauthors= ignored (|author= suggested) (help)
  9. ^ Oftedal, I. (1932). Z. Kristallogr. 83: 9–25. {{cite journal}}: Missing or empty |title= (help)
  10. ^ Berry, L. G. (1954). "The crystal structure of covellite CuS and klockmannite CuSe". American Mineralogist. 39: 504. {{cite journal}}: Cite has empty unknown parameter: |month= (help)
  11. ^ a b Evans, H.T. Jr. (1976). "Crystal structure refinement of covellite". American Mineralogist. 61: 996–1000. {{cite journal}}: Cite has empty unknown parameter: |month= (help); Unknown parameter |coauthors= ignored (|author= suggested) (help)
  12. ^ Wells A.F. (1984) Structural Inorganic Chemistry 5th edition Oxford Science Publications ISBN 0-19-855370-6
  13. ^ Magnetic susceptibility of the elements and inorganic compounds
  14. ^ Nakai, I. (1978). "X-ray photoelectron spectroscopic study of copper minerals". Journal of Inorganic and Nuclear Chemistry. 40 (5): 789–791. doi:10.1016/0022-1902(78)80152-3. {{cite journal}}: Cite has empty unknown parameter: |month= (help); Unknown parameter |coauthors= ignored (|author= suggested) (help)
  15. ^ Folmer, J.C.W. (1980). "The valence of copper in sulfides and selenides: An X-ray photoelectron spectroscopy study". Journal of the Less Common Metals. 76 (1–2): 789–791. doi:10.1016/0022-5088(80)90019-3. {{cite journal}}: Unknown parameter |coauthors= ignored (|author= suggested) (help)
  16. ^ Folmer, J.C.W. (1988). "The electronic structure of pyrites, particularly CuS2 and Fe1−xCuxSe2: An XPS and Mössbauer study". Journal of Solid State Chemistry. 72 (1): 137–144. doi:10.1016/0022-4596(88)90017-5. {{cite journal}}: Unknown parameter |coauthors= ignored (|author= suggested) (help)
  17. ^ Goh, S.W. (2006). "Copper(II) sulfide?". Minerals Engineering. 19 (2): 204–208. doi:10.1016/j.mineng.2005.09.003. {{cite journal}}: Unknown parameter |coauthors= ignored (|author= suggested) (help); Unknown parameter |month= ignored (help)
  18. ^ Cotton, F. Albert; Wilkinson, Geoffrey; Murillo, Carlos A.; Bochmann, Manfred (1999), Advanced Inorganic Chemistry (6th ed.), New York: Wiley-Interscience, ISBN 0-471-19957-5
  19. ^ a b Liang, W. (1993). "Conductivity anisotropy and structural phase transition in Covellite CuS". Solid State Communications. 85 (5): 405–408. doi:10.1016/0038-1098(93)90689-K. {{cite journal}}: Unknown parameter |coauthors= ignored (|author= suggested) (help); Unknown parameter |month= ignored (help)
  20. ^ Nozaki, H (1991). "Metallic hole conduction in CuS". Journal of Solid State Chemistry. 91 (2): 306–311. doi:10.1016/0022-4596(91)90085-V. {{cite journal}}: Unknown parameter |coauthors= ignored (|author= suggested) (help); Unknown parameter |month= ignored (help)
  21. ^ Luther, GW (2002). "Aqueous copper sulfide clusters as intermediates during copper sulfide formation". Environ. Sci. Technol. 36 (3): 394–402. doi:10.1021/es010906k. PMID 11871554. {{cite journal}}: Unknown parameter |coauthors= ignored (|author= suggested) (help); Unknown parameter |month= ignored (help)
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