Lithium cyanide

Lithium cyanide

Identifiers
CAS Number	2408-36-8
3D model (Jmol)	Interactive image
ChemSpider	68007
ECHA InfoCard	100.017.554
PubChem	754-78
UN number	1935
SMILES [Li+].[C-]#N
Properties
Chemical formula	LiCN
Molar mass	32.959 g/mol
Appearance	White Powder
Density	1.073 g/cm3 (18 °C)
Melting point	160 °C (320 °F; 433 K) Dark colored
Boiling point	N/A
Solubility in water	Soluble
Henry's law constant (kH)	N/A
Structure
Crystal structure	-
Coordination geometry	Fourfold
Hazards
Safety data sheet	742899
EU classification (DSD)	T+, Very Toxic N, Dangerous for the environment
R-phrases	26/27/28-32-50/53
S-phrases	7-28-29-45-60-61
NFPA 704	0 4
Flash point	57 °C (135 °F; 330 K)
Autoignition temperature	N/A
Related compounds
Related compounds	Sodium cyanide, Potassium cyanide, Hydrogen cyanide
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
Infobox references

Lithium cyanide is an inorganic compound with the chemical formula LiCN. It is a white powder at room temperature. Lithium cyanide is commonly used as a reagent in inorganic/organometallic reactions. Lithium cyanide can be found in the environment from the reaction of lithium and acetonitrile, both found in lithium sulfur oxide batteries. When the compound is exposed to the environment it can produce toxic fumes with weak acids found in nature.

Lithium cyanide as a solid is stable at room temperature. LiCN, when melted at 160 °C, is highly hygroscopic. The compound decomposes to cyanamide and carbon when heated to a temperature close to but below 600°C. When acids, chlorates, and other strong oxidizing agents react with LiCN, HCN is formed. HCN vapors are very toxic and reactive. If LiCN is heated in fire carbon dioxide CO₂, nitrogen oxides NO_x, and lithium oxide will form.

Lithium cyanide can be synthesized in high yields with liquid hydrogen cyanide and n-butyllithium. Other methods exist, in which the lithium cation is added to the cyanide anion.

Lithium cyanide is commonly used as a reagent in syntheses of cyanide compounds, for example halide cyanides. The reagent offers the advantage of allowing non-aqueous methods of cyanation.

Lithium cyanide is an inorganic compound not commonly found in nature without human involvement. The most obtainable source of lithium is lithium batteries. Specifically, lithium sulfur dioxide batteries can lead to the formation of lithium cyanide from the reaction between the two chemicals found inside the battery, elemental lithium and acetonitrile. When lithium cyanide is introduced into the environment, it can react with acids or strong oxidizing agents to produce toxic HCN vapors in the environment or can produce carbon dioxide, nitrogen oxides, and lithium oxide if introduced to fire. Concerns about the hazardous nature of lithium sulfur oxide batteries waste were raised as lithium batteries became more obtainable. The US Environmental Protection Agency and Department of Defense evaluated the lithium sulfur oxide batteries and concluded that LiCN formation was one of the compounds leading to the hazardous waste.