Molecular structure:

IUPAC Name: Chlorocopper
Synonyms of Copper(I) Chloride (CAS NO.7758-89-6): Cuprous chloride ; Chlorid medny ; Chlorid medny [Czech] ; Copper monochloride ; Copper(1+) chloride ; Cuprous chloride ; Dicopper dichloride ; Copper chloride ; Copper(I) chloride
Product Categories: Inorganic Chemicals ; Inorganics 
Molecular Weight: 98.999 [g/mol]
Molecular Formula: ClCu
EINECS: 231-842-9 
Density: 1.15 g/mL at 20 °C
Melting Point: 430 °C(lit.)
Flash Point: 1490°C
Boiling Point: 1490 °C(lit.)
Vapour Pressure: 33900 mmHg at 25 °C
Enthalpy of Vaporization: 16.15 kJ/mol
Refractive Index: 1.93
Solubility 0.06 g/L (25 °C)
Form: beads
Water Solubility: 0.06 g/L (25 °C)
Sensitive: Air & Moisture Sensitive
Merck: 14,2660
Stability: Stable. Incompatible with oxidizing agents, potassium, water. Air, light and moisture sensitive.

 The main use of Copper(I) Chloride (CAS NO.7758-89-6) is as a precursor to the fungicide copper oxychloride. For this purpose aqueous Copper(I) Chloride is generated by comproportionation and then air-oxidized:
Cu + CuCl₂ → 2 CuCl
6 CuCl + 3/2 O₂ + 3 H₂O → 2 Cu₃Cl₂(OH)₄ + CuCl₂

Copper and its compounds are on the Community Right-To-Know List. Reported in EPA TSCA Inventory. EPA Genetic Toxicology Program.

Poison by ingestion and subcutaneous routes. Mutation data reported. Reacts violently with potassium or with lithium nitride + heat. When heated to decomposition it emits toxic fumes of Cl⁻. See also CHLORIDES and COPPER COMPOUNDS. 
Hazard Codes: Xn,N
Risk Statements:
R22: Harmful if swallowed. 
R50/53: Very toxic to aquatic organisms, may cause long-term adverse effects in the aquatic environment. 
R51/53: Toxic to aquatic organisms, may cause long-term adverse effects in the aquatic environment. 
R36/37/38: Irritating to eyes, respiratory system and skin.
Safety Statements:
S26: In case of contact with eyes, rinse immediately with plenty of water and seek medical advice. 
S61: Avoid release to the environment. Refer to special instructions / safety data sheets. 
S60: This material and its container must be disposed of as hazardous waste. 
S22: Do not breathe dust.
RIDADR: UN 3082 9/PG 3
WGK Germany: 2
RTECS: GL6990000
F 1: Sensitive to air and humidity.
F 8: Photosensitive.
F 10: Keep under argon.
HazardClass: 8
PackingGroup: III

ACGIH TLV: TWA (fume) 0.2 mg/m³; (dust, mist) 1 mg(Cu)/m³

 Copper(I) Chloride (CAS NO.7758-89-6) commonly called cuprous chloride, is the lower chloride of copper, with the formula CuCl. This colorless solid is a versatile precursor to other copper compounds, including some of commercial significance. It occurs naturally as the rare mineral nantokite. Unlike other first-row transition metal halides, it forms stable complexes with carbon monoxide. It crystallizes in a diamondoid motif, reflecting the tendency of copper(I) to form tetrahedral complexes.
Although CuCl is insoluble in water, it dissolves in aqueous solutions containing suitable donor molecules. It forms complexes with halide ions, for example forming H₃O+ CuCl₂- with concentrated hydrochloric acid. It also dissolves in solutions containing CN-, S₂O₃₂-, and NH₃ to give complexes.
Solutions of CuCl in HCl or NH₃ absorb carbon monoxide to form colourless complexes such as the chloride-bridged dimer [CuCl(CO)]₂. The same hydrochloric acid solutions also react with acetylene gas to form [CuCl(C₂H₂)]. Ammoniacal solutions of CuCl react with acetylenes to form the explosive copper(I) acetylide. Complexes of CuCl with alkenes can be prepared by reduction of CuCl₂ by sulfur dioxide in the presence of the alkene in alcohol solution. Complexes with dienes such as 1,5-cyclooctadiene are particularly stable: