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The tricyano ion is sparingly soluble in water whereas the tetracyano ion is very soluble. [Cu(CN)2]- is insoluble.
CuCN comes as a pale yellow powder from Fluka and Aldrich, sample which have been kept in damp conditions go pale green. PXRD does not show any impurity peaks.
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| Formula = CuCN
| Formula = CuCN
| MolarMass = 89.563 g/mol
| MolarMass = 89.563 g/mol
| Appearance = white to greenish powder
| Appearance = off-white to greenish powder
| Density = 2.92 g/cm<sup>3</sup><ref>{{RubberBible87th}}</ref>
| Density = 2.92 g/cm<sup>3</sup><ref>{{RubberBible87th}}</ref>
| MeltingPtC = 474
| MeltingPtC = 474
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}}
}}


'''Copper(I) cyanide''' in an [[inorganic compound]] with the formula CuCN. This white solid occurs in two [[polymorph]]s; impure samples are often off-white. The compound is useful as a [[catalyst]], in electroplating copper, and as a [[reagent]] in the preparation of [[nitrile]]s.<ref name=Ullmann>H. Wayne Richardson "Copper Compounds" in Ullmann's Encyclopedia of Industrial Chemistry, Wiley-VCH, Weinheim, 2005. {{DOI|10.1002/14356007.a07_567}}</ref>
'''Copper(I) cyanide''' in an [[inorganic compound]] with the formula CuCN. This off-white solid occurs in two [[polymorph]]s; impure samples can be green due to Cu(II) species. The compound is useful as a [[catalyst]], in electroplating copper, and as a [[reagent]] in the preparation of [[nitrile]]s.<ref name=Ullmann>H. Wayne Richardson "Copper Compounds" in Ullmann's Encyclopedia of Industrial Chemistry, Wiley-VCH, Weinheim, 2005. {{DOI|10.1002/14356007.a07_567}}</ref>


==Structure==
==Structure==
⚫
The compound is a [[coordination polymer]], because that the copper(I) centres are linked by [[cyanide]] [[bridging ligand|bridges]]. Both polymorphs contain -[Cu-CN]- chains. In high-temperature polymorph, HT-CuCN, which is isostructural with [[silver cyanide|AgCN]], the linear chains pack on a hexagonal lattice and adjacent chains are off set by +/- 1/3 ''c''.<ref>{{cite journal | author = S. J. Hibble, S. M. Cheyne, A. C. Hannon and S. G. Eversfield | title = CuCN: A Polymorphic Matirial. Structure of One Form from Total Neutron Diffraction | journal = [[Inorg. Chem.]] | year = 2002 | volume = 41 | pages = 8040–8048 | doi = 10.1021/ic0257569}}</ref> In the low-temperature polymorph, LT-CuCN, the chains deviate from linearity and pack into rippled layers which pack in an AB fashion with chains in adjacent layers rotated by 49 °.<ref>{{cite journal | author = S. J. Hibble, S. G. Eversfield, A. R. Cowley and A. M. Chippindale | title = Copper(I) Cyanide: A Simple Compound with a complicated Structure and Suprissing Room-Temperature Reactivity | journal = [[Angew. Chem. Int. Ed.]] | year = 2004 | volume = 43 | pages = 628–630 | doi = 10.1002/anie.200352844}}</ref> LT-CuCN can be converted to HT-CuCN by heating to 563 K in an inert atmosphere. In both polymorphs the bridging cyanide groups show head-to-tail disorder.<ref>{{cite journal | author = S. Kroeker, R. E. Wasylishen and J. V. Hanna | title = The Structure of Solid Copper(I) Cyanide: A Multinuclear Magnetic and Quadrupole Resonance Study. | journal = Journal of the American Chemical Society | year = 1999 | volume = 121 | pages = 1582-158x | doi = 10.1021/ja983253p}}</ref> Cuprous cyanide is commercially available and is supplied as the low-temperature polymorph. It may be prepared by reducing [[copper(II) sulfate]] with [[sodium cyanide]], giving [[cyanogen]] gas and [[sodium sulfate]] as byproducts:<ref>{{OrgSynth | author = J. V. Supniewski and P. L. Salzberg | title = Allyl Cyanide | collvol = 1 | collvolpages = 46 | year = 1941 | prep = CV1P0046}}</ref>
The compound is a [[coordination polymer]], because that the copper(I) centres are linked by [[cyanide]] [[bridging ligand|bridges]].
⚫
Both polymorphs contain -[Cu-CN]- chains. In high-temperature polymorph, HT-CuCN, which is isostructural with [[silver cyanide|AgCN]], the linear chains pack on a hexagonal lattice and adjacent chains are off set by +/- 1/3 ''c''.<ref>{{cite journal | author = S. J. Hibble, S. M. Cheyne, A. C. Hannon and S. G. Eversfield | title = CuCN: A Polymorphic Matirial. Structure of One Form from Total Neutron Diffraction | journal = [[Inorg. Chem.]] | year = 2002 | volume = 41 | pages = 8040–8048 | doi = 10.1021/ic0257569}}</ref> In the low-temperature polymorph, LT-CuCN, the chains deviate from linearity and pack into rippled layers which pack in an AB fashion with chains in adjacent layers rotated by 49 °.<ref>{{cite journal | author = S. J. Hibble, S. G. Eversfield, A. R. Cowley and A. M. Chippindale | title = Copper(I) Cyanide: A Simple Compound with a complicated Structure and Suprissing Room-Temperature Reactivity | journal = [[Angew. Chem. Int. Ed.]] | year = 2004 | volume = 43 | pages = 628–630 | doi = 10.1002/anie.200352844}}</ref> LT-CuCN can be converted to HT-CuCN by heating to 563 K in an inert atmosphere. In both polymorphs the bridging cyanide groups show head-to-tail disorder.<ref>{{cite journal | author = S. Kroeker, R. E. Wasylishen and J. V. Hanna | title = The Structure of Solid Copper(I) Cyanide: A Multinuclear Magnetic and Quadrupole Resonance Study. | journal = Journal of the American Chemical Society | year = 1999 | volume = 121 | pages = 1582-158x | doi = 10.1021/ja983253p}}</ref> Cuprous cyanide is commercially available and is supplied as the low-temperature polymorph. It may be prepared by reducing [[copper(II) sulfate]] with [[sodium cyanide]], giving [[cyanogen]] gas and [[sodium sulfate]] as byproducts:<ref>{{OrgSynth | author = J. V. Supniewski and P. L. Salzberg | title = Allyl Cyanide | collvol = 1 | collvolpages = 46 | year = 1941 | prep = CV1P0046}}</ref>


: 2 CuSO<sub>4</sub> + 4 NaCN &rarr; 2 CuCN + (CN)<sub>2</sub> + 2 Na<sub>2</sub>SO<sub>4</sub>
: 2 CuSO<sub>4</sub> + 4 NaCN &rarr; 2 CuCN + (CN)<sub>2</sub> + 2 Na<sub>2</sub>SO<sub>4</sub>

Revision as of 13:02, 3 February 2011

Copper(I) cyanide
Names
IUPAC name
Copper(I) cyanide
Other names
Cuprous cyanide, copper cyanide, cupricin
Identifiers
3D model (JSmol)
ChemSpider
ECHA InfoCard 100.008.076 Edit this at Wikidata
EC Number
  • 208-883-6
RTECS number
  • GL7150000
  • InChI=1S/CN.Cu/c1-2;/q-1;+1 checkY
    Key: DOBRDRYODQBAMW-UHFFFAOYSA-N checkY
  • InChI=1/CN.Cu/c1-2;/q-1;+1
    Key: DOBRDRYODQBAMW-UHFFFAOYAI
  • [Cu+].[C-]#N
Properties
CuCN
Molar mass 89.563 g/mol
Appearance off-white to greenish powder
Density 2.92 g/cm3[1]
Melting point 474 °C (885 °F; 747 K)
negligible
Solubility insoluble in ethanol, cold dilute acids;
soluble in NH4OH, KCN
Hazards
NFPA 704 (fire diamond)
NFPA 704 four-colored diamondHealth 4: Very short exposure could cause death or major residual injury. E.g. VX gasFlammability 0: Will not burn. E.g. waterInstability 0: Normally stable, even under fire exposure conditions, and is not reactive with water. E.g. liquid nitrogenSpecial hazards (white): no code
4
0
0
Flash point Non-flammable
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
checkY verify (what is checkY☒N ?)

Copper(I) cyanide in an inorganic compound with the formula CuCN. This off-white solid occurs in two polymorphs; impure samples can be green due to Cu(II) species. The compound is useful as a catalyst, in electroplating copper, and as a reagent in the preparation of nitriles.[2]

Structure

The compound is a coordination polymer, because that the copper(I) centres are linked by cyanide bridges. Both polymorphs contain -[Cu-CN]- chains. In high-temperature polymorph, HT-CuCN, which is isostructural with AgCN, the linear chains pack on a hexagonal lattice and adjacent chains are off set by +/- 1/3 c.[3] In the low-temperature polymorph, LT-CuCN, the chains deviate from linearity and pack into rippled layers which pack in an AB fashion with chains in adjacent layers rotated by 49 °.[4] LT-CuCN can be converted to HT-CuCN by heating to 563 K in an inert atmosphere. In both polymorphs the bridging cyanide groups show head-to-tail disorder.[5] Cuprous cyanide is commercially available and is supplied as the low-temperature polymorph. It may be prepared by reducing copper(II) sulfate with sodium cyanide, giving cyanogen gas and sodium sulfate as byproducts:[6]

2 CuSO4 + 4 NaCN → 2 CuCN + (CN)2 + 2 Na2SO4

This synthesis generates cyanogen, (CN)2(g), which is very toxic and does not give pure CuCN. A neater synthesis is the reduction of copper(II) sulfate with sodium bisulphite at 60 °C, followed by the addition of sodium cyanide precipitating pure LT-CuCN as a pale yellow powder. [7]

2 CuSO4 + NaHSO3 + H2O + 2 NaCN → 2 CuCN + 3 NaHSO4

Copper cyanide is insoluble in water but dissolves in solutions containing free CN- to form [Cu(CN)4]3-.

References

  1. ^ Lide, David R., ed. (2006). CRC Handbook of Chemistry and Physics (87th ed.). Boca Raton, FL: CRC Press. ISBN 0-8493-0487-3.
  2. ^ H. Wayne Richardson "Copper Compounds" in Ullmann's Encyclopedia of Industrial Chemistry, Wiley-VCH, Weinheim, 2005. doi:10.1002/14356007.a07_567
  3. ^ S. J. Hibble, S. M. Cheyne, A. C. Hannon and S. G. Eversfield (2002). "CuCN: A Polymorphic Matirial. Structure of One Form from Total Neutron Diffraction". Inorg. Chem. 41: 8040–8048. doi:10.1021/ic0257569.{{cite journal}}: CS1 maint: multiple names: authors list (link)
  4. ^ S. J. Hibble, S. G. Eversfield, A. R. Cowley and A. M. Chippindale (2004). "Copper(I) Cyanide: A Simple Compound with a complicated Structure and Suprissing Room-Temperature Reactivity". Angew. Chem. Int. Ed. 43: 628–630. doi:10.1002/anie.200352844.{{cite journal}}: CS1 maint: multiple names: authors list (link)
  5. ^ S. Kroeker, R. E. Wasylishen and J. V. Hanna (1999). "The Structure of Solid Copper(I) Cyanide: A Multinuclear Magnetic and Quadrupole Resonance Study". Journal of the American Chemical Society. 121: 1582-158x. doi:10.1021/ja983253p.
  6. ^ J. V. Supniewski and P. L. Salzberg (1941). "Allyl Cyanide". Organic Syntheses; Collected Volumes, vol. 1, p. 46.
  7. ^ H. J. Barber (1942). "Cuprous Cyanide: A Note on its Preparation and Use". J. Chem. Soc.: 79.
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