Copper(II) nitrate

Copper(II) nitrate
IUPAC name

Copper(II) nitrate
Other names

Cupric nitrate
Identifiers
CAS number 3251-23-8 Y
PubChem 18616
ChemSpider 17582 Y
UNII 9TC879S2ZV Y
RTECS number GL7875000
Jmol-3D images Image 1
Properties
Molecular formula Cu(NO3)2
Molar mass 187.56 g/mol (
Appearance blue crystals
hygroscopic
Density 3.05 g/cm3 (anhydrous)
2.32 g/cm3 (trihydrate)
2.07 g/cm3 (hexahydrate)
Melting point

256 °C (anhydrous, decomp)
114 °C (trihydrate)
26 °C (hexahydrate, decomposes)
Boiling point

170 °C (trihydrate, decomposes)
Solubility in water 137.8 g/100 mL (0 °C) (trihydrate)
Solubility hydrates very soluble in ethanol, water
Structure
Crystal structure orthorhombic (anhydrous)
rhombohedral (hydrates)
Hazards
MSDS Cu(NO3)2·3H2O
EU Index Not listed
Main hazards Irritant, Oxidizer
NFPA 704
0
1
1
OX
Related compounds
Other anions Copper(II) sulfate
Copper(II) chloride
Other cations Nickel(II) nitrate
Zinc nitrate
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Except where noted otherwise, data are given for materials in their standard state (at 25 °C, 100 kPa)
Infobox references

Copper(II) nitrate is the chemical compound with the formula Cu(NO3)2. Commonly referred to simply as copper nitrate, the anhydrous form is a blue, crystalline solid. Hydrated forms of copper nitrate, also blue, are commonly used in school laboratories to demonstrate chemical voltaic cell reactions.

Contents

Synthesis and reactions

Cu(NO3)2 forms when copper metal is treated with N2O4:[1]

Cu + 2 N2O4 → Cu(NO3)2 + 2 NO
The structure of anhydrous Cu(NO3)2(gas)[2]

Hydrated copper nitrate can be prepared by hydrolysis of the anhydrous material or by treating copper metal with an aqueous solution of silver nitrate or concentrated nitric acid:

Cu + 4 HNO3 → Cu(NO3)2 + 2 H2O + 2 NO2

Copper nitrate can be used to generate nitric acid by heating it until decomposition and passing the fumes directly into water. This method is similar to the last step in the Ostwald process. The equations are as follows:

2 Cu(NO3)2 → 2 CuO + 4 NO2 + O2
3NO2 + H2O → 2HNO3 + NO

Use in organic synthesis

Copper nitrate, in combination with acetic anhydride, is an effective reagent for nitration of aromatic compounds, under what are known as "Menke conditions", in honor of the Dutch chemist who discovered that metal nitrates are effective reagents for nitration.[3] Hydrated copper nitrate absorbed onto clay affords a reagent called "Claycop". The resulting blue-colored clay is used as a slurry, for example for the oxidation of thiols to disulfides. Claycop is also used to convert dithioacetals to carbonyls.[4] A related reagent based on montmorillonite has proven useful for the nitration of aromatic compounds.[5]

References

  1. ^ Jolly, W. L. "The Synthesis and Characterization of Inorganic Compounds" Prentice Hall, London, 1970
  2. ^ Greenwood, N. N.; Earnshaw, A. (1997). Chemistry of the Elements, 2nd Edition, Oxford:Butterworth-Heinemann. ISBN 0-7506-3365-4.
  3. ^ Menke J.B. (1925). "Nitration with nitrates". Recueil des Travaux Chimiques des Payes-Bas 44: 141. 
  4. ^ Balogh, M. "Copper(II) Nitrate–K10 Bentonite Clay" in Encyclopedia of Reagents for Organic Synthesis (Ed: L. Paquette) 2004, J. Wiley & Sons, New York. DOI: 10.1002/047084289.
  5. ^ Collet, C.; Delville, A.; Laszlo, P. “Clays Direct Aromatic Nitration” Angewandte Chemie International Edition in English, 2003, Volume 29, Issue 5 , Pages 535–536. doi:10.1002/anie.199005351.

External links