Copper monosulfide

Manufacturing

A black colloidal precipitate of copper monosulfide is formed when hydrogen sulfide, , is bubbled through solutions of Cu(II) salts. This is the basis of its industrial production.

Special forms of CuS for certain applications 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. Nanoparticles of CuS can be prepare by reaction of dissolved copper(II) chloride with thioglycolic acid.

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{{cite journal

The crystal structure of covellite has been reported several times,{{cite journal

• 4 Cu atoms have tetrahedral coordination (see illustration).
• 2 Cu atoms have trigonal planar coordination (see illustration).
• 2 pairs of S atoms are only apart 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 sulfide as (i.e. containing no sulfur-sulfur bond) is clearly incompatible with the crystal structure, and also at variance with the observed diamagnetism as a Cu(II) compound would have a d9 configuration and be expected to be paramagnetic.

Studies using XPS{{cite journal Electron paramagnetic resonance studies on the precipitation of Cu(II) salts indicates that the reduction of Cu(II) to Cu(I) occurs in solution.{{cite journal

References

References

1. Blachnik, R.. (2000). "The formation of Cu₂S from the elements I. Copper used in form of powders". Thermochimica Acta.
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..
3. (February 1993). "Conductivity anisotropy and structural phase transition in Covellite CuS". Solid State Communications.
4. Kuchmii, S.Y.. (2001). "Catalysis of the Sodium Sulfide Reduction of Methylviologene by CuS Nanoparticles". Springer.
5. Mane, R.S.. (June 2000). "Chemical deposition method for metal chalcogenide thin films". Materials Chemistry and Physics.
6. (1984). "Structural Inorganic Chemistry". Oxford University Press.
7. {{Greenwood&Earnshaw2nd
8. "Copper Sulfide Nanoparticles for Photothermal Ablation of Tumor Cells". Nanomedicine.
9. (1984). "Structural inorganic chemistry". Clarendon Press; Oxford University Press.
10. [http://www-d0.fnal.gov/hardware/cal/lvps_info/engineering/elementmagn.pdf Magnetic susceptibility of the elements and inorganic compounds] {{webarchive. link. (2012-01-12)
11. {{Cotton&Wilkinson6th