Copper(II) chloride

Copper(II) chloride

Anhydrous
Anhydrous
Dihydrate
Names
Other names Cupric chloride
Identifiers
CAS Number	7447-39-4 Y 10125-13-0 (dihydrate) N
3D model (Jmol)	Interactive image Interactive image
ChEBI	CHEBI:49553 Y
ChEMBL	ChEMBL1200553 N
ChemSpider	148374 Y
ECHA InfoCard	100.028.373
PubChem	24014
RTECS number	GL7000000
UNII	P484053J2Y Y
InChI InChI=1S/2ClH.Cu/h2*1H;/q;;+2/p-2 Y Key: ORTQZVOHEJQUHG-UHFFFAOYSA-L Y InChI=1/2ClH.Cu/h2*1H;/q;;+2/p-2/rCl2Cu/c1-3-2 Key: ORTQZVOHEJQUHG-LRIOHBSEAE InChI=1/2ClH.Cu/h2*1H;/q;;+2/p-2 Key: ORTQZVOHEJQUHG-NUQVWONBAE
SMILES Cl[Cu]Cl [Cu+2].[Cl-].[Cl-]
Properties
Chemical formula	CuCl2
Molar mass	134.45 g/mol (anhydrous) 170.48 g/mol (dihydrate)
Appearance	yellow-brown solid (anhydrous) blue-green solid (dihydrate)
Odor	odorless
Density	3.386 g/cm3 (anhydrous) 2.51 g/cm3 (dihydrate)
Melting point	498 °C (928 °F; 771 K) (anhydrous) 100 °C (dehydration of dihydrate)
Boiling point	993 °C (1,819 °F; 1,266 K) (anhydrous, decomposes)
Solubility in water	70.6 g/100 mL (0 °C) 75.7 g/100 mL (25 °C) 107.9 g/100 mL (100 °C)
Solubility	methanol: 68 g/100 mL (15 °C) ethanol: 53 g/100 mL (15 °C) soluble in acetone
Magnetic susceptibility (χ)	+1080·10−6 cm3/mol
Structure
Crystal structure	distorted CdI2 structure
Coordination geometry	Octahedral
Hazards
Safety data sheet	Fischer Scientific
EU classification (DSD)	Not listed
NFPA 704	0 2 1
Flash point	Non-flammable
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)
Related compounds
Other anions	Copper(II) fluoride Copper(II) bromide
Other cations	Copper(I) chloride Silver chloride Gold(III) chloride
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

ethanol:
53 g/100 mL (15 °C)
soluble in acetone

Copper(II) chloride is the chemical compound with the chemical formula CuCl₂. This is a light brown solid, which slowly absorbs moisture to form a blue-green dihydrate. The copper(II) chlorides are some of the most common copper(II) compounds, after copper sulfate.

Both the anhydrous and the dihydrate forms occur naturally as the very rare minerals tolbachite and eriochalcite, respectively.

Anhydrous CuCl₂ adopts a distorted cadmium iodide structure. In this motif, the copper centers are octahedral. Most copper(II) compounds exhibit distortions from idealized octahedral geometry due to the Jahn-Teller effect, which in this case describes the localization of one d-electron into a molecular orbital that is strongly antibonding with respect to a pair of chloride ligands. In CuCl₂·2H₂O, the copper again adopts a highly distorted octahedral geometry, the Cu(II) centers being surrounded by two water ligands and four chloride ligands, which bridge asymmetrically to other Cu centers.

Copper(II) chloride is paramagnetic. Of historical interest, CuCl₂·2H₂O was used in the first electron paramagnetic resonance measurements by Yevgeny Zavoisky in 1944.

Aqueous solution prepared from copper(II) chloride contain a range of copper(II) complexes depending on concentration, temperature, and the presence of additional chloride ions. These species include blue color of [Cu(H₂O)₆]²⁺ and yellow or red color of the halide complexes of the formula [CuCl_2+x]^x−.

Copper(II) hydroxide precipitates upon treating copper(II) chloride solutions with base:

Partial hydrolysis gives copper oxychloride, Cu₂Cl(OH)₃, a popular fungicide.