Lithium imide is an inorganic compound with the

chemical formula In chemistry, a chemical formula is a way of presenting information about the chemical proportions of atoms that constitute a particular chemical compound or molecule, using chemical element symbols, numbers, and sometimes also other symbol ...

. This white solid can be formed by a reaction between

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 ...

and

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 ...

. : LiNH₂ + LiH → Li₂NH + H₂ The product is light-sensitive and can undergo

disproportionation In chemistry, disproportionation, sometimes called dismutation, is a redox reaction in which one compound of intermediate oxidation state converts to two compounds, one of higher and one of lower oxidation states. More generally, the term can ...

to form

lithium nitride Lithium nitride is a compound 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 ...

, which is characteristically red. :2 Li₂NH → LiNH₂ + Li₃N Lithium imide is thought to have a simple face-centered cubic structure with a Fmm

space group In mathematics, physics and chemistry, a space group is the symmetry group of an object in space, usually in three dimensions. The elements of a space group (its symmetry operations) are the rigid transformations of an object that leave it uncha ...

; with N-H bond distances of 0.82(6) Å and a H–N–H bond angle of 109.5°, giving it a similar structure to lithium amide. Lithium imide is strongly basic and deprotonates even some extremely weak acids such as

methane Methane ( , ) is a chemical compound with the chemical formula (one carbon atom bonded to four hydrogen atoms). It is a group-14 hydride, the simplest alkane, and the main constituent of natural gas. The relative abundance of methane on Ea ...

and

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 ...

, due to the very localized negative charge on the nitrogen, which carries two formal charges. It has uses in organic and organometallic chemistry. It has been investigated as a material for hydrogen storage.

References

Inorganic imides Lithium compounds Nitrogen(−III) compounds Hydrogen compounds {{inorganic-compound-stub