_chloride_pure.jpg) | |
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| Names | |
|---|---|
| IUPAC name Copper(I) chloride | |
| Other names Cuprous chloride | |
| Identifiers | |
3D model (JSmol) | |
| 8127933 | |
| ChEBI | |
| ChemSpider |
|
| DrugBank | |
| ECHA InfoCard | 100.028.948 |
| EC Number |
|
| 13676 | |
| RTECS number |
|
| UNII | |
| |
| |
| Properties | |
| CuCl | |
| Molar mass | 98.999 g/mol[1] |
| Appearance | white powder, slightly green from oxidized impurities |
| Density | 4.14 g/cm3[1] |
| Melting point | 423 °C (793 °F; 696 K)[1] |
| Boiling point | 1,490 °C (2,710 °F; 1,760 K) (decomposes)[1] |
| 0.047 g/L (20 °C)[1] | |
Solubility product (Ksp) | 1.72×10−7 |
| Solubility | insoluble inethanol, acetone;[1] soluble in concentratedHCl,NH4OH |
| Band gap | 3.25 eV (300 K, direct)[2] |
| −40.0·10−6 cm3/mol[3] | |
Refractive index (nD) | 1.930[4] |
| Structure | |
| Zincblende,cF20 | |
| F43m, No. 216[5] | |
a = 0.54202 nm | |
Lattice volume (V) | 0.1592 nm3 |
Formula units (Z) | 4 |
| Hazards | |
| GHS labelling: | |
  | |
| Warning | |
| H302,H410 | |
| P264,P270,P273,P301+P312,P330,P391,P501 | |
| NFPA 704 (fire diamond) | |
| Flash point | Non-flammable |
| Lethal dose or concentration (LD, LC): | |
LD50 (median dose) | 140 mg/kg |
| NIOSH (US health exposure limits): | |
PEL (Permissible) | TWA 1 mg/m3 (as Cu)[6] |
REL (Recommended) | TWA 1 mg/m3 (as Cu)[6] |
IDLH (Immediate danger) | TWA 100 mg/m3 (as Cu)[6] |
| Safety data sheet (SDS) | JT Baker |
| Related compounds | |
Otheranions | Copper(I) fluoride Copper(I) bromide Copper(I) iodide |
Othercations | Silver(I) chloride Gold(I) chloride |
Related compounds | Copper(II) chloride |
Except where otherwise noted, data are given for materials in theirstandard state (at 25 °C [77 °F], 100 kPa). | |
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Copper(I) chloride, commonly calledcuprous chloride, is the lowerchloride ofcopper, with the formula CuCl. The substance is a white solid sparingly soluble in water, but very soluble in concentratedhydrochloric acid. Impure samples appear green due to the presence ofcopper(II) chloride (CuCl2).
Copper(I) chloride was first prepared byRobert Boyle and designatedrosin of copper in the mid-seventeenth century frommercury(II) chloride ("Venetian sublimate") and copper metal:[7]
In 1799,Joseph Proust first differentiated two different chlorides of copper. He prepared CuCl (which he calledwhite muriate of copper) by heating CuCl2 at red heat in the absence of air, causing it to lose half of its combined chlorine followed by removing residual CuCl2 by washing with water.[8]
An acidic solution of CuCl was formerly used to analyze carbon monoxide content in gases, for example in Hempel's gas apparatus where the CuCl absorbs the carbon monoxide.[9] This application was significant during the nineteenth and early twentieth centuries whencoal gas was widely used for heating and lighting.[10]
Copper(I) chloride is produced industrially by the direct combination of copper metal and chlorine at 450–900 °C:[11][12]
Copper(I) chloride can also be prepared byreducing copper(II) chloride withsulfur dioxide, or with ascorbic acid (vitamin C) that acts as areducing sugar:[13][14]
Many other reducing agents can be used.[12]
chloride_crystal_01.jpg)
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Copper(I) chloride has the cubiczincblende crystal structure at ambient conditions. Upon heating to 408 °C the structure changes to hexagonal. Several other crystalline forms of CuCl appear at high pressures (several GPa).[5]
Upon contact withwater, copper(I) chloride slowly undergoesdisproportionation:[15]
In part for this reason, samples in air assume a green coloration.[16]
Copper(I) chloride is aLewis acid. It is classified as soft according to thehard-soft acid-base concept. Thus, it forms a series ofcomplexes with softLewis bases such astriphenylphosphine:
CuCl also forms complexes withhalides. For exampleH3O+ CuCl2− forms in concentratedhydrochloric acid.[17] Chloride is displaced byCN− andS2O32−.[12]
Solutions of CuCl inHCl absorbcarbon monoxide to form colourless complexes such as the chloride-bridged dimer [CuCl(CO)]2. The same hydrochloric acid solutions also react withacetylene gas to form [CuCl(C2H2)].Ammoniacal solutions of CuCl react with acetylenes to form the explosivecopper(I) acetylide, Cu2C2.Alkene complexes of CuCl can be prepared by reduction ofCuCl2 bysulfur dioxide in the presence of the alkene inalcohol solution. Complexes withdienes such as1,5-cyclooctadiene are particularly stable:[18]
The main use of copper(I) chloride is as a precursor to thefungicidecopper oxychloride. For this purpose aqueous copper(I) chloride is generated bycomproportionation and then air-oxidized:[12]
Copper(I) chloride catalyzes a variety oforganic reactions, as discussed above. Its affinity forcarbon monoxide in the presence ofaluminium chloride is exploited in the COPureSM process.[19]
CuCl is used as a co-catalyst withcarbon monoxide, aluminium chloride, andhydrogen chloride in theGatterman-Koch reaction to form benzaldehydes.[20]
In theSandmeyer reaction, the treatment of anarenediazonium salt with CuCl leads to an aryl chloride. For example:[21][22]
The reaction has wide scope and usually gives good yields.[22]
Early investigators observed that copper(I) halides catalyse 1,4-addition ofGrignard reagents to alpha,beta-unsaturated ketones[23] led to the development oforganocuprate reagents that are widely used today inorganic synthesis:[24]
This finding led to the development oforganocopper chemistry. For example, CuCl reacts withmethyllithium (CH3Li) to form "Gilman reagents" such as (CH3)2CuLi, which find use inorganic synthesis.Grignard reagents form similar organocopper compounds. Although other copper(I) compounds such ascopper(I) iodide are now more often used for these types of reactions, copper(I) chloride is still recommended in some cases:[25]
Cuprous chloride also catalyzes thedimerization ofacetylene tovinylacetylene, once used as a precursor to various polymers such aneoprene.[26]
CuCl is used as a catalyst inatom transfer radical polymerization (ATRP). It is also used inpyrotechnics as a blue/green coloring agent. In aflame test, copper chlorides, like all copper compounds, emit green-blue.[27]
Natural form of CuCl is the rare mineralnantokite.[28][29]
