Lithium nitride is a

compound Compound may refer to: Architecture and built environments * Compound (enclosure), a cluster of buildings having a shared purpose, usually inside a fence or wall ** Compound (fortification), a version of the above fortified with defensive struc ...

with the formula Li₃N. It is the only stable alkali metal nitride. The solid has a reddish-pink color and high melting point.

Preparation and handling

Lithium nitride is prepared by direct combination of elemental

lithium Lithium (from el, λίθος, lithos, lit=stone) is a chemical element with the symbol Li and atomic number 3. It is a soft, silvery-white alkali metal. Under standard conditions, it is the least dense metal and the least dense solid ...

with

nitrogen Nitrogen is the chemical element with the symbol N and atomic number 7. Nitrogen is a nonmetal and the lightest member of group 15 of the periodic table, often called the pnictogens. It is a common element in the universe, estimated at se ...

gas: :6 Li + N₂ → 2 Li₃N Instead of burning lithium metal in an atmosphere of nitrogen, a solution of lithium in liquid

sodium Sodium is a chemical element with the symbol Na (from Latin ''natrium'') and atomic number 11. It is a soft, silvery-white, highly reactive metal. Sodium is an alkali metal, being in group 1 of the periodic table. Its only stable ...

metal can be treated with N₂. Lithium nitride reacts violently with

water Water (chemical formula ) is an Inorganic compound, inorganic, transparent, tasteless, odorless, and Color of water, nearly colorless chemical substance, which is the main constituent of Earth's hydrosphere and the fluids of all known living ...

to produce

ammonia Ammonia is an inorganic compound of nitrogen and hydrogen with the formula . A stable binary hydride, and the simplest pnictogen hydride, ammonia is a colourless gas with a distinct pungent smell. Biologically, it is a common nitrogenous wa ...

: :Li₃N + 3 H₂O → 3 LiOH + NH₃

Structure and properties

''alpha''-Li₃N (stable at room temperature and pressure) has an unusual crystal structure that consists of two types of layers, one sheet has the composition Li₂N⁻ contains 6-coordinate N centers and the other sheet consists only of lithium cations. Two other forms are known: ''beta''-Lithium nitride, formed from the alpha phase at has the sodium arsenide (Na₃As) structure; ''gamma''-Lithium nitride (same structure as Li₃Bi) forms from the beta form at . Lithium nitride shows ionic conductivity for Li⁺, with a value of c. 2×10⁻⁴Ω⁻¹cm⁻¹, and an (intracrystal) activation energy of c. 0.26eV (c. 24 kJ/mol). Hydrogen doping increases conductivity, whilst doping with metal ions (Al, Cu, Mg) reduces it. The activation energy for lithium transfer across lithium nitride crystals (intercrystalline) has been determined to be higher at c. 68.5 kJ/mol. The alpha form is a semiconductor with band gap of c. 2.1 eV. Reaction with

hydrogen Hydrogen is the chemical element with the symbol H and atomic number 1. Hydrogen is the lightest element. At standard conditions hydrogen is a gas of diatomic molecules having the formula . It is colorless, odorless, tasteless, non-toxic ...

at under 300 °C (0.5 MPa pressure) produces

lithium hydride Lithium hydride is an inorganic compound with the formula Li H. This alkali metal hydride is a colorless solid, although commercial samples are grey. Characteristic of a salt-like (ionic) hydride, it has a high melting point, and it is not solub ...

and

lithium amide Lithium amide or lithium azanide is an inorganic compound with the chemical formula . It is a white solid with a tetragonal crystal structure. Lithium amide can be made by treating lithium metal with liquid ammonia: : Other lithium amides The co ...

. Lithium nitride has been investigated as a storage medium for

gas, as the reaction is reversible at 270 °C. Up to 11.5% by weight absorption of hydrogen has been achieved. Reacting lithium nitride with carbon dioxide results in amorphous carbon nitride (C₃N₄), a

semiconductor A semiconductor is a material which has an electrical conductivity value falling between that of a conductor, such as copper, and an insulator, such as glass. Its resistivity falls as its temperature rises; metals behave in the opposite way. ...

, and lithium

cyanamide Cyanamide is an organic compound with the formula C N2 H2. This white solid is widely used in agriculture and the production of pharmaceuticals and other organic compounds. It is also used as an alcohol-deterrent drug. The molecule features a ...

(Li₂CN₂), a precursor to

fertilizer A fertilizer (American English) or fertiliser (British English; see spelling differences) is any material of natural or synthetic origin that is applied to soil or to plant tissues to supply plant nutrients. Fertilizers may be distinct from ...

s, in an exothermic reaction.

Preparation and handling

Structure and properties

References

See also