3D model (JSmol)
|Molar mass||76.34 g/mol|
|Melting point||500 °C (932 °F; 773 K) (decomposes)|
|Reacts to form magnesium hydroxide|
|Solubility in ammonia||Slightly soluble|
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, but it has been disproved. If heated to 500 °C, it decomposes to magnesium nitride.
- HCN + Mg → Mg(CN)2 + H2
The instant it was formed, 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. Then, the ammoniate was then heated to 180 °C which decomposed back to magnesium cyanide. Other methods are possible, such as the decomposition of magnesium ferricyanide in an electric carbon tube, which produces iron carbide as a byproduct.
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, 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.
- Kapp, Jürgen; Schleyer, Paul v. R. (1996). "M(CN)2 Species (M = Be, Mg, Ca, Sr, Ba): Cyanides, Nitriles, or Neither?" (in en). Inorg. Chem. (ACS Publications) 35 (8): 2247–2252. doi:10.1021/ic9511837. PMID 11666420.
- Fr. Fichter; Richard Suter (1924). "Über Magnesiumcyanid" (in German). Helvetica (Wiley) 5 (3): 396–400. doi:10.1002/hlca.19220050311.
- A. R. Frank, R. B. Booth, American Cyanamid Co., US Patent 2419931, 1947.
Original source: https://en.wikipedia.org/wiki/Magnesium cyanide. Read more