Copper(II) acetate

Copper(II) acetate

Small crystals of copper(II) acetate
Copper(II) acetate crystals on copper wire
Names
IUPAC name Tetra-μ2-acetatodiaquadicopper(II)
Other names Copper(II) ethanoate Cupric acetate Copper Acetate Verdigris
Identifiers
CAS Number	142-71-2 (anhydrous) Y 6046-93-1 (hydrate) N
3D model (Jmol)	Interactive image
ChemSpider	8555 Y
ECHA InfoCard	100.005.049
PubChem	8895
UNII	39M11XPH03 Y
InChI InChI=1S/2C2H4O2.Cu/c2*1-2(3)4;/h2*1H3,(H,3,4);/q;;+2/p-2 Y Key: OPQARKPSCNTWTJ-UHFFFAOYSA-L Y InChI=1/2C2H4O2.Cu/c2*1-2(3)4;/h2*1H3,(H,3,4);/q;;+2/p-2 Key: OPQARKPSCNTWTJ-NUQVWONBAO
SMILES [Cu+2].[O-]C(=O)C.[O-]C(=O)C
Properties
Chemical formula	Cu(CH3COO)2
Molar mass	181.63 g/mol (anhydrous) 199.65 g/mol (hydrate)
Appearance	Dark green crystalline solid
Odor	odorless (hydrate)
Density	1.882 g/cm3 (hydrate)
Melting point	Undetermined
Boiling point	240 °C (464 °F; 513 K)
Solubility in water	hydrate: 7.2 g/100 mL (cold water) 20 g/100 mL (hot water)
Solubility	Soluble in alcohol Slightly soluble in ether and glycerol
Refractive index (nD)	1.545 (hydrate)
Structure
Crystal structure	Monoclinic
Hazards
Safety data sheet	Baker MSDS
R-phrases	22-36/37/38-50/53
S-phrases	26-60-61
NFPA 704	0 2 0
Flash point	Non-flammable
Lethal dose or concentration (LD, LC):
LD50 (median dose)	710mg/kg oral rat
US health exposure limits (NIOSH):
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).
N  (what is YN ?)
Infobox references

Copper(II) acetate, also referred to as cupric acetate, is the chemical compound with the formula Cu(OAc)₂ where AcO⁻ is acetate (CH
3CO−
2). The hydrated derivative, which contains one molecule of water for each Cu atom, is available commercially. Anhydrous Cu(OAc)₂ is a dark green crystalline solid, whereas Cu₂(OAc)₄(H₂O)₂ is more bluish-green. Since ancient times, copper acetates of some form have been used as fungicides and green pigments. Today, copper acetates are used as reagents for the synthesis of various inorganic and organic compounds. Copper acetate, like all copper compounds, emits a blue-green glow in a flame.

Copper acetate hydrate adopts the paddle wheel structure seen also for related Rh(II) and Cr(II) tetraacetates. One oxygen atom on each acetate is bound to one copper at 1.97 Å (197 pm). Completing the coordination sphere are two water ligands, with Cu–O distances of 2.20 Å (220 pm). The two five-coordinate copper atoms are separated by only 2.62 Å (262 pm), which is close to the Cu–Cu separation in metallic copper. The two copper centers interact resulting in a diminishing of the magnetic moment such that near 90 K, Cu₂(OAc)₄(H₂O)₂ is essentially diamagnetic due to cancellation of the two opposing spins. Cu₂(OAc)₄(H₂O)₂ was a critical step in the development of modern theories for antiferromagnetic coupling.