|Molar mass||98.999 g/mol|
|Appearance||white powder, slightly green from oxidized impurities|
|Melting point||426 °C (799 °F; 699 K)|
|Boiling point||1,490 °C (2,710 °F; 1,760 K) (decomposes)|
|0.0062 g/100 mL (20 °C)|
Solubility product (Ksp)
|1.72 x 10−7|
|Solubility||insoluble in ethanol
acetone; soluble in concentrated HCl, NH4OH
Refractive index (nD)
|Crystal structure||Zinc blende structure|
|EU classification||Harmful (Xn)
Dangerous for the environment (N)
|S-phrases||(S2), S22, S60, S61|
LD50 (Median lethal dose)
Except where noted otherwise, data is given for materials in their standard state (at 25 °C (77 °F), 100 kPa)
|what is: / ?)(|
Copper(I) chloride, commonly called cuprous chloride, is the lower chloride of copper, with the formula CuCl. The substance is a white solid sparingly soluble in water, but very soluble in concentrated hydrochloric acid. Impure samples appear green due to the presence of copper(II) chloride.
- HgCl2 + 2 Cu → 2 CuCl + Hg
In 1799, J.L. Proust characterized the two different chlorides of copper. He prepared CuCl 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.
An acidic solution of CuCl was formerly used for analysis of carbon monoxide content in gases, for example in Hempel's gas apparatus. This application was significant during the time that coal gas was widely used for heating and lighting, during the nineteenth and early twentieth centuries.
- CuCl + P(C6H5)3 → [CuCl(P(C6H5)3)]4
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 is attacked by CN−, S2O32−, and NH3 to give the corresponding 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, Cu2C2. 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:
In absence of other ligands, its aqueous solutions are unstable with respect to disproportionation into Cu and CuCl2. In part for this reason samples in air assume a green coloration (see photograph in upper right).
- Cu + CuCl2 → 2 CuCl
- 6 CuCl + 3/2 O2 + 3 H2O → 2 Cu3Cl2(OH)4 + CuCl2
In organic synthesis
The reaction has wide scope and usually gives good yields.
Early investigators observed that copper(I) halides catalyse 1,4-addition of Grignard reagents to alpha,beta-unsaturated ketones led to the development of organocuprate reagents that are widely used today in organic synthesis:
This finding led to the development of organocopper chemistry. For example, CuCl reacts with methyllithium (CH3Li) to form "Gilman reagents" such as (CH3)2CuLi, which find extensive use in organic synthesis. Grignard reagents form similar organocopper compounds. Although other copper(I) compounds such as copper(I) iodide are now more often used for these types of reactions, copper(I) chloride is still recommended in some cases:
In polymer chemistry
CuCl is used as a catalyst in Atom Transfer Radical Polymerization (ATRP).
- Pradyot Patnaik. Handbook of Inorganic Chemicals. McGraw-Hill, 2002, ISBN 0-07-049439-8
- United States Patent US4582579 "method of preparing cupric ion free cuprous chloride" Section 2, lines 4-41 , via www.freepatentsonline.com
- Boyle, Robert (1666). Considerations and experiments about the origin of forms and qualities. Oxford. As reported in Mellor.
- Proust, J. L. (1799). Ann. Chim. Phys. (1) 32: 26. Missing or empty
- Martin, Geoffrey (1917). Industrial and Manufacturing Chemistry (Part 1, Organic ed.). London: Crosby Lockwood. pp. 330–31.
- Lewes, Vivian H. (1891). "Journal of the Society of Chemical Industry". Journal of the Society of Chemical Industry 10: 407–413.
- Nicholls, D. Complexes and First-Row Transition Elements, Macmillan Press, London, 1973.
- Greenwood, N.N.; Earnshaw, A. Chemistry of the Elements, 2nd ed., Butterworth-Heinemann, Oxford, UK, 1997.
- (a) Wade, L. G. Organic Chemistry, 5th ed., p. 871, Prentice Hall, Upper Saddle RIver, New Jersey, 2003. (b) March, J. Advanced Organic Chemistry, 4th ed., p. 723, Wiley, New York, 1992.
- Kharasch, M. S; Tawney, P. O (1941). "Factors Determining the Course and Mechanisms of Grignard Reactions. II. The Effect of Metallic Compounds on the Reaction between Isophorone and Methylmagnesium Bromide". J. Am. Chem. Soc. 63 (9): 2308. doi:10.1021/ja01854a005.
- Jasrzebski, J. T. B. H.; van Koten, G. in Modern Organocopper Chemistry, (N. Krause, ed.), p. 1, Wiley-VCH, Weinheim, Germany, 2002.
- (a) Bertz, S. H.; Fairchild, E. H. in Handbook of Reagents for Organic Synthesis, Volume 1: Reagents, Auxiliaries and Catalysts for C-C Bond Formation, (R. M. Coates, S. E. Denmark, eds.), pp. 220-3, Wiley, New York, 1999. (b) Munch-Petersen, J., et al., Acta Chimica Scand., 15, 277 (1961).
- Mellor, J. W., A Comprehensive Treatise on Inorganic and Theoretical Chemistry, Volume III, pp157–168. Longmans, Green & Co., London, 1967 (new impression).
|Wikimedia Commons has media related to Copper(I) chloride.|
- National Pollutant Inventory - Copper and compounds fact sheet
- The COPureSM Process for purifying CO utilizing a copper chloride complex