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Cadmium cyanide

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Cadmium cyanide
Cadmium cyanide
Names
IUPAC name
Cadmium(II) cyanide
Identifiers
3D model (JSmol)
ChemSpider
ECHA InfoCard 100.008.027Edit this at Wikidata
UNII
  • InChI=1S/2CN.Cd/c2*1-2;/q2*-1;+2checkY
    Key: NHMJUOSYSOOPDM-UHFFFAOYSA-NcheckY
  • InChI=1/2CN.Cd/c2*1-2;/q2*-1;+2
    Key: NHMJUOSYSOOPDM-UHFFFAOYAI
  • [Cd+2].[C-]#N.[C-]#N
Properties
Cd(CN)2
Molar mass 164.45 g/mol
Appearance white cubic crystals
Density 2.226 g/cm3
1.71 g/100 mL (15 °C)
2.2 g/100 mL (20 °C)
Solubility slightly soluble inalcohol
dissolves in alkali, metal cyanides and hydroxides
-54.0·10−6cm3/mol
Hazards
NIOSH(US health exposure limits):
PEL(Permissible)
[1910.1027] TWA 0.005 mg/m3(as Cd)[1]
REL(Recommended)
Ca[1]
IDLH(Immediate danger)
Ca [9 mg/m3(as Cd)][1]
Related compounds
Otheranions
Cadmium chloride,
Cadmium iodide
Othercations
Zinc cyanide,
Calcium cyanide,
Magnesium cyanide
Except where otherwise noted, data are given for materials in theirstandard state(at 25 °C [77 °F], 100 kPa).

Cadmium cyanideis aninorganic compoundwith theformulaCd(CN)2.It is a white crystalline compound that is used in electroplating.[2]It is very toxic, along with othercadmiumandcyanidecompounds.

Preparation and structure

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Cadmium cyanide is prepared commercially by treatingcadmium hydroxidewithhydrogen cyanide:[3]

Cd(OH)2+ 2 HCN → Cd(CN)2+ 2 H2O

It can also be generated from tetracyanocadmate:

[Cd(CN)4]2−+ CdCl2→ 2 Cd(CN)2+ 2 Cl
Structure of theclathrateconsisting of cadmium cyanide host andcarbon tetrachlorideguest, Cd(CN)2.CCl4.Blue = Cd(CN)2framework, gray = C, green = disordered Cl.

Cadmium cyanide andzinc cyanideadopt similar structures.[4]As such, each metal hastetrahedral coordination sphere.Cyanide ligandsinterconnectpairs of metal centers. Two of the resultingdiamondoidstructures areinterpenetrated.The structure is related to that ofcristobalite,apolymorphsof SiO2.This structural similarity of cadmium dicyanide and cristobalite was foundational in the development of mineralomimetic chemistry: "the build-up of mineral-like structures using materials that never give stable minerals."[5]

Reactions and uses

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It is used as anelectrolytefor electrodeposition of thin metallic cadmium coatings on metal to protect againstcorrosion.

Like zinc cyanide, cadmium cyanide is fairly soluble in water, which is unusual for transition metal cyanides. The solubility increases with the additional cyanide, this reaction proceeding via "[Cd(CN)3]"and [Cd(CN)4]2−.With acids, its solutions evolvehydrogen cyanide.When it is crystallizes in the presence of certain small molecules, it formsclathrates.[4]

References

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  1. ^abcNIOSH Pocket Guide to Chemical Hazards."#0087".National Institute for Occupational Safety and Health(NIOSH).
  2. ^Lide, David R., ed. (2006).CRC Handbook of Chemistry and Physics(87th ed.). Boca Raton, FL:CRC Press.ISBN0-8493-0487-3.
  3. ^Karl-Heinz Schulte-Schrepping, Magnus Piscator "Cadmium and Cadmium Compounds" in Ullmann's Encyclopedia of Industrial Chemistry, 2007 Wiley-VCH, Weinheim.doi:10.1002/14356007.a04_499.
  4. ^abGreenwood, Norman N.;Earnshaw, Alan (1997).Chemistry of the Elements(2nd ed.).Butterworth-Heinemann.ISBN978-0-08-037941-8.
  5. ^Iwamoto, Toschitake; Nishikiori, Shin-ichi; Kitazawa, Takafumi; Yuge, Hidetaka (1997). "Mineralomimetic chemistry as a modern aspect of co-ordination chemistry".Journal of the Chemical Society, Dalton Transactions(22): 4127–4136.doi:10.1039/A702539D..