Copper(I) sulfate

Copper(I) sulfate
Names
	IUPAC name Copper(I) sulfate
	Systematic IUPAC name Copper(I) sulfate
	Other names Copper sulfate; Cuprous sulfate; Dicopper sulfate;
Identifiers
CAS Number	17599-81-4;
3D model (JSmol)	Interactive image;
ChemSpider	118749;
ECHA InfoCard	100.159.746
PubChem CID	134737;
CompTox Dashboard (EPA)	DTXSID30889663 ;
	InChI InChI=1S/2Cu.H2O4S/c;;1-5(2,3)4/h;;(H2,1,2,3,4)/q2+1;/p-2 Key: WIVXEZIMDUGYRW-UHFFFAOYSA-L; InChI=1/2Cu.H2O4S/c;;1-5(2,3)4/h;;(H2,1,2,3,4)/q2+1;/p-2 Key: WIVXEZIMDUGYRW-NUQVWONBAI;
	SMILES [O-]S(=O)(=O)[O-].[Cu+].[Cu+];
Properties
Chemical formula	Cu2SO4
Molar mass	223.15 g mol−1
Appearance	White
Density	4.12 g cm−3
Melting point	110 °C
Solubility in water	decomposes
Structure
Crystal structure	orthorhombic
Space group	Fddd
Lattice constant	a = 4.748(3) Å, b = 13.96(1) Å, c = 10.86(1) Å
Formula units (Z)	8
Hazards
	GHS labelling:
Pictograms
Signal word	Warning
Hazard statements	H302, H315, H319, H400
Precautionary statements	P264, P264+P265, P270, P273, P280, P301+P317, P302+P352, P305+P351+P338, P321, P330, P332+P317, P337+P317, P362+P364, P391, P501
	NIOSH (US health exposure limits):
PEL (Permissible)	TWA 1 mg/m3 (as Cu)
REL (Recommended)	TWA 1 mg/m3 (as Cu)
IDLH (Immediate danger)	TWA 100 mg/m3 (as Cu)
	Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). Infobox references

Copper(I) sulfate, also known as cuprous sulfate, is an inorganic compound with the chemical formula Cu₂ SO₄. It is a white solid, in contrast to copper(II) sulfate, which is blue in hydrous form. Compared to the commonly available reagent, copper(II) sulfate, copper(I) sulfate is unstable and not readily available.^[1]

Structure

Cu₂SO₄ crystallizes in the orthorhombic space group Fddd. Each oxygen in a sulfate anion is bridged to another sulfate by a copper atom, and the Cu−O distances are 196 pm.^[1]

Synthesis

Cuprous sulfate is produced by the reaction of copper metal with sulfuric acid at 200 °C:^[4]

2 Cu + 2 H₂SO₄ → Cu₂SO₄ + SO₂ + 2 H₂O

Cu₂SO₄ can also be synthesized by the action of dimethyl sulfate on cuprous oxide:^[5]

Cu₂O + (CH₃O)₂SO₂ → Cu₂SO₄ + (CH₃)₂O

Reactions

The material is stable in dry air at room temperature but decomposes rapidly in presence of moisture or upon heating. It decomposes into copper(II) sulfate pentahydrate upon contact with water.^[5]

Cu₂SO₄ + 5 H₂O → Cu + CuSO₄ · 5 H₂O

Related compounds

A copper(I) sulfate metal-organic framework (MOF) with the formula Cu₂(4,4′-bpy)₂SO₄·6(H₂O) has been characterized.^[6] It is prepared by hydrothermal synthesis involving copper(II) sulfate pentahydrate, L-aspartic acid, and 4,4′-bipyridine.^[6] It is a heterogeneous catalyst for the cyclopropanation of styrene, with high trans cyclopropane diastereoselectivity.^[6]

References

^ ^a ^b ^c ^d Berthold, H. J.; Born, J.; Wartchow, R. (1988). "The crystal structure of copper(I)sulfate Cu₂SO₄ – The first structure of a simple cuprous oxo-salt". Zeitschrift für Kristallographie – Crystalline Materials. 183: 309–318. doi:10.1524/zkri.1988.183.14.309. S2CID 101673081.
^ ^a ^b ^c NIOSH Pocket Guide to Chemical Hazards. "#0150". National Institute for Occupational Safety and Health (NIOSH).
^ PubChem. "Sulfuric acid, copper(1+) salt (1:2)". pubchem.ncbi.nlm.nih.gov. Retrieved 2026-02-17.
^ O. Glemser; R. Sauer (1963). "Copper (I) Sulfate". In G. Brauer (ed.). Handbook of Preparative Inorganic Chemistry, 2nd Ed. Vol. 2pages=1020. NY, NY: Academic Press.
^ ^a ^b Vo Van, Kim; Habashi, Faith (1972). "Identification and Thermal Stability of Copper(I) Sulfate". Can. J. Chem. 50 (23): 3872–3875. doi:10.1139/v72-610.
^ ^a ^b ^c Shi, Fa-Nian; Silva, Ana Rosa; Rocha, João (2011-08-01). "Metal-organic framework based on copper(I) sulfate and 4,4′-bipyridine catalyzes the cyclopropanation of styrene". Journal of Solid State Chemistry. 184 (8): 2196–2203. doi:10.1016/j.jssc.2011.06.023. ISSN 0022-4596.

[ZKrist-1] Berthold, H. J.; Born, J.; Wartchow, R. (1988). "The crystal structure of copper(I)sulfate Cu₂SO₄ – The first structure of a simple cuprous oxo-salt". Zeitschrift für Kristallographie – Crystalline Materials. 183: 309–318. doi:10.1524/zkri.1988.183.14.309. S2CID 101673081.

[PGCH-2] NIOSH Pocket Guide to Chemical Hazards. "#0150". National Institute for Occupational Safety and Health (NIOSH).

[3] PubChem. "Sulfuric acid, copper(1+) salt (1:2)". pubchem.ncbi.nlm.nih.gov. Retrieved 2026-02-17.

[4] O. Glemser; R. Sauer (1963). "Copper (I) Sulfate". In G. Brauer (ed.). Handbook of Preparative Inorganic Chemistry, 2nd Ed. Vol. 2pages=1020. NY, NY: Academic Press.

[VoVan-5] Vo Van, Kim; Habashi, Faith (1972). "Identification and Thermal Stability of Copper(I) Sulfate". Can. J. Chem. 50 (23): 3872–3875. doi:10.1139/v72-610.

[Shi-6] Shi, Fa-Nian; Silva, Ana Rosa; Rocha, João (2011-08-01). "Metal-organic framework based on copper(I) sulfate and 4,4′-bipyridine catalyzes the cyclopropanation of styrene". Journal of Solid State Chemistry. 184 (8): 2196–2203. doi:10.1016/j.jssc.2011.06.023. ISSN 0022-4596.

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