Lanthanum(III) sulfide

Lanthanum(III) sulfide is a binary inorganic chemical compound of lanthanum metal and sulfur with the chemical formula . At least three polymorphs are known, referred to as α, β, and γ.

Synthesis

Lanthanum(III) sulfide can directly be produced by treating metallic lanthanum with sulfur:

Once prepared, lanthanum(III) sulfide can be purified by chemical vapor transport using iodine.

Lanthanum(III) sulfide can also be prepared by treating the sulfate with hydrogen sulfide at elevated temperatures:

Physical properties

Dilanthanum trisulfide forms reddish-yellow crystals of the cubic system, with space group I43d, and unit cell parameters a = 0.8706 nm. The α polymorph features two types of La3+ centers, one with Capped trigonal prismatic molecular geometry and one is bicapped trigonal prismatic molecular geometry.

It does not dissolve in cold water.

Chemical properties

• Reacts with hot water:

:

• Reacts with acids:

:

• Oxidized by oxygen in atmosphere:

:

Uses

is used as a precursor to prepare complex compounds. It is also used in glass manufacturing and in optical fibers.

References