Magnesium cyanide

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Magnesium cyanide
Other names
  • Magnesium dicyanide
  • Magnesium(II) cyanide
3D model (JSmol)
PubChem CID
  • InChI=1S/2CN.Mg/c2*1-2;/q2*-1;+2
  • [C-]#N.[C-]#N.[Mg+2]
Molar mass 76.34 g/mol
AppearanceWhite solid
Melting point 500 °C (932 °F; 773 K) (decomposes)
Reacts to form magnesium hydroxide
Solubility in ammoniaSlightly soluble
Related compounds
Other anions
Magnesium thiocyanate
Other cations
Calcium cyanide
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).

Magnesium cyanide is a chemical compound with the formula Mg(CN)2. It is a toxic white solid. It has been theorized that it is a nitrile compound,[ clarification needed ] but it has been disproved. [1] If heated to 500 °C, it decomposes to magnesium nitride. [2]



The first attempt to prepare magnesium cyanide was attempted in 1924. It was attempted by reacting a solution of hydrogen cyanide in water with magnesium metal: [2]

HCN + Mg → Mg(CN)2 + H2

The instant it was formed,[ verification needed ] it reacted with water to form magnesium hydroxide. To avoid this problem, instead of using water as the reaction medium, pure ammonia was used at -30 °C. This formed magnesium cyanide ammoniate, which in turn was heated to 180 °C to produce magnesium cyanide. [3] Other methods are possible, such as the decomposition of magnesium ferricyanide in an electric carbon tube, which produces iron carbide as a byproduct. [2]


Magnesium cyanide reacts with silver nitrate to form magnesium silver cyanide, with the formula MgAg2(CN)4. When this compound is heated it produces hydrogen cyanide gas and magnesium hydroxide,[ dubious ] which meant it could not be used as a pathway for the production of magnesium cyanide. When silver nitrate reacts with magnesium cyanide, it also produces another magnesium silver cyanide, with the formula MgAg(CN)3. [2]

Related Research Articles

<span class="mw-page-title-main">Cyanide</span> Any molecule with a cyano group (–C≡N)

In chemistry, a cyanide is a chemical compound that contains a C≡N functional group. This group, known as the cyano group, consists of a carbon atom triple-bonded to a nitrogen atom.

<span class="mw-page-title-main">Alkaline earth metal</span> Group of chemical elements

The alkaline earth metals are six chemical elements in group 2 of the periodic table. They are beryllium (Be), magnesium (Mg), calcium (Ca), strontium (Sr), barium (Ba), and radium (Ra). The elements have very similar properties: they are all shiny, silvery-white, somewhat reactive metals at standard temperature and pressure.

<span class="mw-page-title-main">Potassium ferrocyanide</span> Chemical compound

Potassium ferrocyanide is the inorganic compound with formula K4[Fe(CN)6]·3H2O. It is the potassium salt of the coordination complex [Fe(CN)6]4−. This salt forms lemon-yellow monoclinic crystals.

<span class="mw-page-title-main">Sodium cyanide</span> Chemical compound

Sodium cyanide is a poisonous compound with the formula NaCN. It is a white, water-soluble solid. Cyanide has a high affinity for metals, which leads to the high toxicity of this salt. Its main application, in gold mining, also exploits its high reactivity toward metals. It is a moderately strong base.

In organic chemistry, a nitrile is any organic compound that has a −C≡N functional group. The prefix cyano- is used interchangeably with the term nitrile in industrial literature. Nitriles are found in many useful compounds, including methyl cyanoacrylate, used in super glue, and nitrile rubber, a nitrile-containing polymer used in latex-free laboratory and medical gloves. Nitrile rubber is also widely used as automotive and other seals since it is resistant to fuels and oils. Organic compounds containing multiple nitrile groups are known as cyanocarbons.

<span class="mw-page-title-main">Potassium cyanide</span> Highly toxic crystalline salt

Potassium cyanide is a compound with the formula KCN. This colorless, highly toxic crystalline salt, similar in appearance to sugar, is highly soluble in water. Most KCN is used in gold mining, organic synthesis, and electroplating. Smaller applications include jewellery for chemical gilding and buffing.

<span class="mw-page-title-main">Magnesium nitrate</span> Chemical compound

Magnesium nitrate refers to inorganic compounds with the formula Mg(NO3)2(H2O)x, where x = 6, 2, and 0. All are white solids. The anhydrous material is hygroscopic, quickly forming the hexahydrate upon standing in air. All of the salts are very soluble in both water and ethanol.

<span class="mw-page-title-main">Potassium nitrite</span> Chemical compound

Potassium nitrite (distinct from potassium nitrate) is the inorganic compound with the chemical formula KNO2. It is an ionic salt of potassium ions K+ and nitrite ions NO2, which forms a white or slightly yellow, hygroscopic crystalline powder that is soluble in water.

Cyanogen bromide is the inorganic compound with the formula (CN)Br or BrCN. It is a colorless solid that is widely used to modify biopolymers, fragment proteins and peptides, and synthesize other compounds. The compound is classified as a pseudohalogen.

<span class="mw-page-title-main">Trimethylsilyl cyanide</span> Chemical compound

Trimethylsilyl cyanide is the chemical compound with the formula (CH3)3SiCN. This volatile liquid consists of a cyanide group, that is CN, attached to a trimethylsilyl group. The molecule is used in organic synthesis as the equivalent of hydrogen cyanide. It is prepared by the reaction of lithium cyanide and trimethylsilyl chloride:

<span class="mw-page-title-main">Silver compounds</span> Chemical compounds containing silver

Silver is a relatively unreactive metal, although it can form several compounds. The common oxidation states of silver are (in order of commonness): +1 (the most stable state; for example, silver nitrate, AgNO3); +2 (highly oxidising; for example, silver(II) fluoride, AgF2); and even very rarely +3 (extreme oxidising; for example, potassium tetrafluoroargentate(III), KAgF4). The +3 state requires very strong oxidising agents to attain, such as fluorine or peroxodisulfate, and some silver(III) compounds react with atmospheric moisture and attack glass. Indeed, silver(III) fluoride is usually obtained by reacting silver or silver monofluoride with the strongest known oxidizing agent, krypton difluoride.

Magnesium compounds are compounds formed by the element magnesium (Mg). These compounds are important to industry and biology, including magnesium carbonate, magnesium chloride, magnesium citrate, magnesium hydroxide, magnesium oxide, magnesium sulfate, and magnesium sulfate heptahydrate.

<span class="mw-page-title-main">Magnesium iodide</span> Chemical compound

Magnesium iodide is an inorganic compound with the chemical formula MgI2. It forms various hydrates MgI2·xH2O. Magnesium iodide is a salt of magnesium and hydrogen iodide. These salts are typical ionic halides, being highly soluble in water.

<span class="mw-page-title-main">Cadmium hydroxide</span> Chemical compound

Cadmium hydroxide is an inorganic compound with the formula Cd(OH)2. It is a white crystalline ionic compound that is a key component of nickel–cadmium battery.

<span class="mw-page-title-main">Magnesium acetate</span> Chemical compound

Anhydrous magnesium acetate has the chemical formula Mg(C2H3O2)2 and in its hydrated form, magnesium acetate tetrahydrate, it has the chemical formula Mg(CH3COO)2 • 4H2O. In this compound magnesium has an oxidation state of 2+. Magnesium acetate is the magnesium salt of acetic acid. It is deliquescent and upon heating, it decomposes to form magnesium oxide. Magnesium acetate is commonly used as a source of magnesium in biological reactions.

<span class="mw-page-title-main">Ammonium cyanide</span> Chemical compound

Ammonium cyanide is an unstable inorganic compound with the formula NH4CN.

<span class="mw-page-title-main">Lithium cyanide</span> Toxic crystalline salt

Lithium cyanide is an inorganic compound with the chemical formula LiCN. It is a toxic, white coloured, hygroscopic, water-soluble salt that finds only niche uses.

<span class="mw-page-title-main">Barium cyanide</span> Chemical compound

Barium cyanide is a chemical compound with the formula Ba(CN)2. It is synthesized by the reaction of hydrogen cyanide and barium hydroxide in water or petroleum ether. It is a white crystalline salt.

Magnesium chlorate is an inorganic chemical consisting of a magnesium cation and two chlorate anions: its chemical formula is Mg(ClO3)2.

Silver chlorite is a chemical compound with the formula AgClO2. This slightly yellow solid is shock sensitive and has an orthorhombic crystal structure.


  1. Kapp, Jürgen; Schleyer, Paul v. R. (1996). "M(CN)2 Species (M = Be, Mg, Ca, Sr, Ba): Cyanides, Nitriles, or Neither?". Inorg. Chem. ACS Publications. 35 (8): 2247–2252. doi:10.1021/ic9511837. PMID   11666420.
  2. 1 2 3 4 Fr. Fichter; Richard Suter (1924). "Über Magnesiumcyanid". Helvetica (in German). Wiley. 5 (3): 396–400. doi:10.1002/hlca.19220050311.
  3. A. R. Frank, R. B. Booth, American Cyanamid Co., US Patent 2419931, 1947.