Cadmium cyanide: Difference between revisions

| verifiedrevid = 400824385

| Name = Cadmium cyanide

| ImageFile =Cd(CN)2.jpg

| ImageName = Cadmium cyanide

| IUPACName = Cadmium(II) cyanide

| OtherNames =

|Section1={{Chembox Identifiers

| ChemSpiderID_Ref = {{chemspidercite|correct|chemspider}}

| CASNo_Ref = {{cascite|correct|??}}

| CASNoOther =

| UNII_Ref = {{fdacite|correct|FDA}}

| UNII = L520HA8ZUK

| RTECS =

|Section2={{Chembox Properties

| Formula = Cd(CN)₂

| MolarMass = 164.45 g/mol

| Appearance = white cubic crystals

| Density = 2.226 g/cm³

| Solubility = 1.71 g/100 mL (15 °C) <br> 2.2 g/100 mL (20 °C)<!--<ref>{{cite journal|title=The Solubility of Some Sparingly Soluble Salts of Zinc and Cadmium in Water and in Aqueous Electrolyte Solutions|author1=Clever, H. Lawrence|author2=Derrick, M. Elizabeth|author3=Johnson, Susan A.|journal=Journal of Physical and Chemical Reference Data|year=2014|doi=10.1063/1.555909}}</ref>-->

| SolubleOther = slightly soluble in [[ethanol|alcohol]] <br> dissolves in alkali, metal cyanides and hydroxides

| MeltingPt =

| BoilingPt =

| MagSus = -54.0·10⁻⁶ cm³/mol

|Section3={{Chembox Structure

| Coordination =

| CrystalStruct =

|Section7={{Chembox Hazards

| ExternalSDS =

| REL = Ca<ref name=PGCH>{{PGCH|0087}}</ref>

| PEL = [1910.1027] TWA 0.005 mg/m³ (as Cd)<ref name=PGCH/>

| IDLH = Ca [9 mg/m³ (as Cd)]<ref name=PGCH/>

|Section8={{Chembox Related

| OtherAnions = [[Cadmium chloride]],<br />[[Cadmium iodide]]

| OtherCations = [[Zinc cyanide]],<br />[[Calcium cyanide]],<br />[[Magnesium cyanide]]

'''Cadmium cyanide''' is an [[inorganic compound]] with the [[chemical formula|formula]] Cd(CN)₂. It is a white crystalline compound that is used in electroplating.<ref>{{RubberBible87th}}</ref> It is very toxic, along with other [[cadmium]] and [[cyanide]] compounds.

__TOC__

Cadmium cyanide is prepared commercially by treating [[cadmium hydroxide]] with [[hydrogen cyanide]]:<ref name=Ullmann>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}}.</ref>

It can also be generated from tetracyanocadmate:

:[Cd(CN)₄]²⁻ + CdCl₂ → 2 Cd(CN)₂ + 2 Cl⁻

[[File:Cd(CN)2CCl4.jpg|thumb|left|248px|Structure of the [[clathrate]] consisting of cadmium cyanide host and [[carbon tetrachloride]] guest, Cd(CN)₂^.CCl₄. Blue = Cd(CN)₂ framework, gray = C, green = disordered Cl.]]

Cadmium cyanide and [[zinc cyanide]] adopt similar structures.<ref name=G&W>{{Greenwood&Earnshaw2nd}}</ref> As such, each metal has [[tetrahedral molecular geometry|tetrahedral coordination sphere]]. Cyanide ligands [[bridging ligand|interconnect]] pairs of metal centers. Two of the resulting [[diamondoid]] structures are [[Interpenetrating polymer network|interpenetrated]]. The structure is related to that of [[cristobalite]], a [[Polymorphism (materials science)|polymorph]]s of 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."<ref>{{cite journal|title=Mineralomimetic chemistry as a modern aspect of co-ordination chemistry|author1=Iwamoto, Toschitake|author2=Nishikiori, Shin-ichi|author3=Kitazawa, Takafumi|author4=Yuge, Hidetaka|journal=Journal of the Chemical Society, Dalton Transactions|issue=22|year=1997|pages=4127–4136|doi=10.1039/A702539D}}.</ref>

==Reactions and uses==

It is used as an [[electrolyte]] for electrodeposition of thin metallic cadmium coatings on metal to protect against [[corrosion]].

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 evolve [[hydrogen cyanide]]. When it is crystallizes in the presence of certain small molecules, it forms [[clathrate]]s.<ref name=G&W/>

{{Cyanides}}

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