Copper monosulfide

Copper monosulfide
Names
IUPAC name
Copper sulfide
Other names
Covellite
Copper(II) sulfide
Cupric sulfide
Identifiers
1317-40-4 YesY
ChemSpider 14145 YesY
Jmol 3D model Interactive image
PubChem 14831
RTECS number GL8912000
Properties
CuS
Molar mass 95.611 g/mol
Appearance black powder or lumps
Density 4.76 g/cm3
Melting point above 500 °C (932 °F; 773 K) (decomposes)[1]
0.000033 g/100 mL (18 °C)
6 x 10−37[2]
Solubility soluble in HNO3, NH4OH, KCN
insoluble in HCl, H2SO4
1.45
Structure
hexagonal
Hazards
US health exposure limits (NIOSH):
PEL (Permissible)
 TWA 1 mg/m3 (as Cu)[3]
REL (Recommended)
 TWA 1 mg/m3 (as Cu)[3]
IDLH (Immediate danger)
 TWA 100 mg/m3 (as Cu)[3]
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).
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Infobox references

Copper 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.[4] A black colloidal precipitate of CuS is formed when hydrogen sulfide, H2S, is bubbled through solutions of Cu(II) salts.[5] 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[6] and photovoltaics.[7]

Manufacturing

Copper sulfide can be prepared by passing hydrogen sulfide gas into a solution of copper salt.

Alternatively, it can be prepared by melting an excess of sulfur with copper(I) sulfide or by precipitation with hydrogen sulfide from a solution of anhydrous copper(II) chloride in anhydrous ethanol.

The reaction of copper with molten sulfur followed by boiling sodium hydroxide and the reaction of sodium sulfide with aqueous copper sulfate will also produce copper sulfide.

CuS structure and bonding

Copper sulfide crystallizes in the hexagonal crystal system, and this is the form of the mineral covellite. There is also an amorphous high pressure form [8] 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.[9]
The crystal structure of covellite has been reported several times,[10][11][12] 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[13] 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:

The formulation of copper sulfide as CuIIS (i.e. containing no sulfur-sulfur bond) is clearly incompatible with the crystal structure, and also at variance with the observed diamagnetism [14] as a Cu(II) compound would have a d9 configuration and be expected to be paramagnetic.[5]
Studies using XPS[15][16][17][18] 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.[5][19]) 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.[20] The formulation should not be interpreted as containing radical anion, but rather that there is a delocalized valence "hole".[20][21] Electron paramagnetic resonance studies on the precipitation of Cu(II) salts indicates that the reduction of Cu(II) to Cu(I) occurs in solution.[22]


[[

Image:Covellite-xtal-CM-3D-balls.png|200px]]
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. ↑ Blachnik, R.; Müller, A. (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. ↑ Rollie J. Myers (1986). "The new low value for the second dissociation constant for H2S: Its history, its best value, and its impact on the teaching of sulfide equilibria". J. Chem. Educ. 63: 687. doi:10.1021/ed063p687.
  3. 1 2 3 "NIOSH Pocket Guide to Chemical Hazards #0150". National Institute for Occupational Safety and Health (NIOSH).
  4. ↑ Wells A.F. (1962) Structural Inorganic Chemistry 3d edition Oxford University Press
  5. 1 2 3 Greenwood, Norman N.; Earnshaw, Alan (1997). Chemistry of the Elements (2nd ed.). Butterworth-Heinemann. ISBN 0-08-037941-9.
  6. ↑ 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 (New York: Springer) 37 (1): 36–41. doi:10.1023/A:1010465823376.
  7. ↑ Mane, R.S.; Lokhande C.D. (June 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.
  8. ↑ Peiris, M; Sweeney, J.S.; Campbell, A.J.; Heinz D. L. (1996). "Pressure-induced amorphization of covellite, CuS". J. Chem. Phys. 104 (1): 11–16. Bibcode:1996JChPh.104...11P. doi:10.1063/1.470870.
  9. ↑ Grijalva, H.; Inoue, M.; Boggavarapu, S.; Calvert, P. (1996). "Amorphous and crystalline copper sulfides, CuS". J. Mater. Chem. 6 (7): 1157–1160. doi:10.1039/JM9960601157.
  10. ↑ Oftedal, I. (1932). Z. Kristallogr. 83: 9–25. Missing or empty |title= (help)
  11. ↑ Berry, L. G. (1954). "The crystal structure of covellite CuS and klockmannite CuSe". American Mineralogist 39: 504.
  12. 1 2 Evans, H.T. Jr.; Konnert J. (1976). "Crystal structure refinement of covellite". American Mineralogist 61: 996–1000.
  13. ↑ Wells A.F. (1984) Structural Inorganic Chemistry 5th edition Oxford Science Publications ISBN 0-19-855370-6
  14. ↑ Magnetic susceptibility of the elements and inorganic compounds
  15. ↑ Nakai, I.; Sugitani, Y.; Nagashima, K.; Niwa, Y. (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.
  16. ↑ Folmer, J.C.W.; Jellinek F. (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.
  17. ↑ Folmer, J.C.W.; Jellinek F.; Calis G.H.M (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. Bibcode:1988JSSCh..72..137F. doi:10.1016/0022-4596(88)90017-5.
  18. ↑ Goh, S.W.; Buckley A.N.; Lamb R.N. (February 2006). "Copper(II) sulfide?". Minerals Engineering 19 (2): 204–208. doi:10.1016/j.mineng.2005.09.003.
  19. ↑ 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
  20. 1 2 Liang, W.; Whangbo M, -H (February 1993). "Conductivity anisotropy and structural phase transition in Covellite CuS". Solid State Communications 85 (5): 405–408. Bibcode:1993SSCom..85..405L. doi:10.1016/0038-1098(93)90689-K.
  21. ↑ Nozaki, H; Shibata, K; Ohhashi,N. (April 1991). "Metallic hole conduction in CuS". Journal of Solid State Chemistry 91 (2): 306–311. Bibcode:1991JSSCh..91..306N. doi:10.1016/0022-4596(91)90085-V.
  22. ↑ Luther, GW; Theberge SM; Rozan TF; Rickard D; Rowlands CC; Oldroyd A. (February 2002). "Aqueous copper sulfide clusters as intermediates during copper sulfide formation.". Environ. Sci. Technol. 36 (3): 394–402. Bibcode:2002EnST...36..394L. doi:10.1021/es010906k. PMID 11871554.
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