Lithium nitride

Red-brown solid with ammoniacal odor

Fixed

1.38 g · cm -3

845 ° C

Reacts violently with water

Risk

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Lithium nitride, Li3N, is a chemical compound, which is constructed from lithium and nitrogen.

Synthesis

Lithium nitride is formed by reaction of lithium with nitrogen. The reaction proceeds already at room temperature, but is very slow, so that for the synthesis of lithium nitride usually higher temperatures are used:

Structure

In the lithium nitride, lithium atoms form graphite-like hexagonal rings in the center of which a nitrogen atom is located. Other lithium atoms are located above and so that each nitrogen is surrounded in a hexagonal bipyramidal geometry of eight lithium nuclei below the nitrogen nucleus.

Properties

Physical Properties

Lithium nitride is a fine, red - brown powder with a density of 1.38 g · cm -3 at standard conditions. It melts at 845 ° C and is stable under exclusion of moisture and air. Lithium nitride is a good ionic conductor.

The enthalpy of formation of lithium nitride is -207 kJ / mol.

Chemical Properties

Lithium nitride is a super base, since the N3 - ion reacts strongly basic. With water lithium nitride, lithium hydroxide and hydrolyzed to ammonia.

When heated in a hydrogen stream to form lithium hydride. As intermediates arise lithium amide ( LiNH 2 ) and lithium imide ( Li2NH ).

Upon heating of lithium nitride with metal chlorides, lithium chloride and the metal nitride question form.

Use

In metallurgy, lithium nitride is used for the introduction of nitrogen into alloys.

Researchers at the National University of Singapore discovered that lithium nitride can hold up to 9.3% hydrogen. The hydrogen atoms are incorporated in the crystal lattice of the nitride. For an application, however, the required temperatures of 255 ° C is still too high.