LITHIUM NITRIDE

Chemical properties

reddish brown crystal(s) or freely flowing powder(s); slowly decomposed by atmospheric moisture; ruby red; hexagonal, a=0.3658 nm, c=0.3882nm; conductivity, 227°C, 0.04 (ohm· cm)?1; one of most effective solid ionic conductors; can be prepared by direct reaction of Li and nitrogen; used as a nitriding agent in metallurgy [HAW93] [STR93] [CIC73] [KIR81]

The Uses of LITHIUM NITRIDE

Lithium nitride is used in metallurgy and chemical synthesis. It is also used to store hydrogen and acts as a source of the nitride ion. It is involved in the preparation of lithium hydride and lithium amide as well as a reducing agent.

Preparation

Lithium nitride is prepared by the reaction of nitrogen gas with lithium metal. The reaction may be carried out at temperatures well above the melting point of lithium metal or using solid lithium metal at temperatures even below 100°C. Lithium nitride, a red crystalline solid, reacts with water to yield lithium hydroxide and ammonia. It is ultimately converted to lithium carbonate in the air. The compound readily reacts with water and carbon dioxide. It is also flammable, particularly when it is finely divided. For these reasons lithium nitride is stored and handled under an inert atmosphere.

Definition

ChEBI: Lithium nitride is a lithium salt and a nitride.

General Description

A reddish brown powder. Insoluble in most organic solvents. Used in metallurgy and chemical synthesis.

Reactivity Profile

LITHIUM NITRIDE is a strongly basic reducing agent. Incompatible with oxidizing agents such as atmospheric oxygen. Violently incompatible with acids, particularly oxidizing acids. Reacts violently with copper(I) chloride to produce metallic copper [Mellor, 1940, vol.8, 100]. Reacts exothermically with silicon tetrafluoride, leading to explosion [Chem. Brit., 1979, 15, 282-283].

Health Hazard

Inhalation or contact with vapors, substance or decomposition products may cause severe injury or death. May produce corrosive solutions on contact with water. Fire will produce irritating, corrosive and/or toxic gases. Runoff from fire control may cause pollution.

Fire Hazard

Produce flammable gases on contact with water. May ignite on contact with water or moist air. Some react vigorously or explosively on contact with water. May be ignited by heat, sparks or flames. May re-ignite after fire is extinguished. Some are transported in highly flammable liquids. Runoff may create fire or explosion hazard.

Flammability and Explosibility

Pyrophoric

Safety Profile

A powerful reducing agent. Upon contact with moisture, it decomposes into lithmm hydroxide, lithium compounds, and ammonia. The powder may ignite spontaneously in moist air. Flammable at elevated temperatures; ignites and burns intensely in air. Violent reaction with dicon tetrafluoride, copperp) chloride + heat. To fight fire, use dry chemical, sand, graphite; avoid use of water or carbon tetrachloride. When heated to decomposition it emits very toxic fumes of Liz0 and NOx. Used as a strong reducing agent in organic synthesis and a solid electrolyte in lithium batteries. See also LITHIUM COMPOUNDS and NITRIDES.