Lanthanum(III) sulfide

Lanthanum(III) sulfide

Names
IUPAC name lanthanum(3+);trisulfide
Other names Dilanthanum trisulfide, lanthanum sesquisulfide
Identifiers
CAS Number	12031-49-1
3D model (JSmol)	Interactive image
ChemSpider	145449
ECHA InfoCard	100.031.580
EC Number	235-592-1
PubChem CID	165996
CompTox Dashboard (EPA)	DTXSID40923320
InChI InChI=1S/2La.3S/q2*+3;3*-2 Key: YTYSNXOWNOTGMY-UHFFFAOYSA-N
SMILES [S-2].[S-2].[S-2].[La+3].[La+3]
Properties
Chemical formula	La2S3
Molar mass	373.99 g·mol−1
Appearance	reddish-yellow crystals
Density	4.9 g/cm3 [1]
Melting point	2,100 °C (3,810 °F; 2,370 K)
Solubility in water	reacts with hot water
Hazards
GHS labelling:
Pictograms
Structure
Crystal structure	cubic
Related compounds
Other cations	Cerium(III) sulfide, Promethium(III) sulfide
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). Infobox references

Lanthanum(III) sulfide is a binary inorganic chemical compound of lanthanum metal and sulfur with the chemical formula La₂S₃. At least three polymorphs are known, referred to as α, β, and γ. ^{[2] [3]}

Synthesis

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

2La + 3S → La₂S₃

Once prepared, lanthanum(III) sulfide can be purified by chemical vapor transport using iodine. ^[4]

Lanthanum(III) sulfide can also be prepared by treating the sulfate with hydrogen sulfide at elevated temperatures: ^[5]

La₂(SO₄)₃ + 12 H₂S → La₂S₃ + 12 H₂O + 12 S

Physical properties

Dilanthanum trisulfide forms reddish-yellow crystals of the cubic system, with space group I43d, and unit cell parameters a = 0.8706 nm. ^[6] The α polymorph features two types of La3+ centers, one with Capped trigonal prismatic molecular geometry and one is bicapped trigonal prismatic molecular geometry. ^[2]

It does not dissolve in cold water.

Chemical properties

• Reacts with hot water:

La₂S₃ + 6 H₂O → 2 La(OH)₃ + 3 HS

• Reacts with acids:

La₂S₃ + 3 HCl → 2 LaCl₃ + 3 H₂S

• Oxidized by oxygen in atmosphere:

2 La₂S₃ + 9 O₂ → 2 La₂O₃ + 6 SO₂

Uses

La₂S₃ is used as a precursor to prepare complex compounds. It is also used in glass manufacturing and in optical fibers. ^[7]

References

1. "Lanthanum Sulfide". American Elements . Retrieved 27 July 2024.
2. Basançon, P.; Adolphe, C.; Flahaut, J.; Laruelle, P. (1969). "Sur les varietes α et β des sulfures L2S3 des terres rares". Materials Research Bulletin. 4 (4): 227–237. doi:10.1016/0025-5408(69)90098-1.
3. Bouroushian, Mirtat (23 April 2010). Electrochemistry of Metal Chalcogenides. Springer Science & Business Media. p. 32. ISBN   978-3-642-03967-6 . Retrieved 27 July 2024.
4. A. W. Sleight and D. P. Kelly (1973), Aaron Wold and John K. Ruff (ed.), Rare-earth Sesquisulfides, Ln₂S₃, Inorganic Syntheses, vol. 14, McGraw-Hill Book Company, Inc., pp. 152–155
5. K. Wetzel (1963). "Lanthanum Sulfides". In G. Brauer (ed.). Handbook of Preparative Inorganic Chemistry, 2nd Ed. Vol. 2. NY, NY: Academic Press. p. 1153.
6. Macintyre, Jane E. (23 July 1992). Dictionary of Inorganic Compounds. CRC Press. p. 3548. ISBN   978-0-412-30120-9 . Retrieved 27 July 2024.
7. "Lanthanum(III) sulfide, 99% (REO), Thermo Scientific Chemicals | Fisher Scientific". Fisher Scientific . Retrieved 27 July 2024.