Barium sulfide

Barium sulfide
Identifiers
CAS number	21109-95-5 Y
PubChem	6857597
ChemSpider	5256933 Y
EC number	244-214-4
ChEBI	CHEBI:32590 Y
Jmol-3D images	Image 1
SMILES [Ba+2].[S-2]
InChI InChI=1S/Ba.S/q+2;-2 Y Key: CJDPJFRMHVXWPT-UHFFFAOYSA-N Y InChI=1/Ba.S/q+2;-2 Key: CJDPJFRMHVXWPT-UHFFFAOYAO
Properties
Molecular formula	BaS
Molar mass	169.39 g/mol
Density	4.25 g/cm3 [1]
Melting point	1200 °C
Boiling point	decomposes
Solubility in water	2.88 g/cm3 (0 °C) 7.68 g/cm3 (20 °C) 60.3 g/100 mL (100 °C)
Solubility	insoluble in alcohol
Refractive index (nD)	2.155
Structure
Crystal structure	Halite (cubic), cF8
Space group	Fm3m, No. 225
Coordination geometry	Octahedral (Ba2+); octahedral (S2–)
Hazards
EU Index	016-002-00-X
EU classification	Harmful (Xn) Dangerous for the environment (N)
R-phrases	R20/22, R31, R50
S-phrases	(S2), S28, S61
NFPA 704	3 2 0
Related compounds
Other anions	Barium oxide
Other cations	Magnesium sulfide Calcium sulfide Strontium sulfide
Y (verify) (what is: Y/N?) Except where noted otherwise, data are given for materials in their standard state (at 25 °C, 100 kPa)
Infobox references

Barium sulfide is the inorganic compound with the formula BaS. BaS is an important precursor to other barium compounds including BaCO₃ and the pigment lithopone, ZnS/BaSO₄.^[2] Like other chalcogenides of the alkaline earth metals, BaS is a short wavelength emitters for electronic displays.^[3] It is colorless, although like many sulfides, it is commonly obtained in impure colored forms.

Discovery, production, properties

The BaS was prepared by Vincentius (or Vincentinus) Casciarolus (or Casciorolus, 1571-1624) via reduction of BaSO₄ (available as the mineral barite).^[4] It is currently manufactured by an improved version of Casciarolus's route using coke in place of flour. This kind of conversion is called a carbothermic reaction:

BaSO₄ + 2 C → BaS + 2 CO₂

The phosphorescence of the substance made the material a curiosity and various alchemists and chemists made experiments with the material which was known as Lapis Boloniensis, Chrysolapis or bologna stone.^[5][6][7]

Andreas Sigismund Marggraf showed that calcite and gypsum were not very suitable for the production of the bologna stone, but a special heavy fluorspar, in the end he concluded that calcium sulfate is the material from which the bologna stone is made.^[8]

BaS crystallizes with the NaCl structure, featuring octahedral Ba²⁺ and S^2- centres.

Safety

BaS is quite poisonous, as are related sulfides, such as CaS, which evolve toxic hydrogen sulfide upon contact with water.

References

1. ^ Lide, David R., ed. (2006). CRC Handbook of Chemistry and Physics (87th ed.). Boca Raton, FL: CRC Press. ISBN 0-8493-0487-3. 
2. ^ Holleman, A. F.; Wiberg, E. "Inorganic Chemistry" Academic Press: San Diego, 2001. ISBN 0-12-352651-5.
3. ^ Vij, D. R.; Singh, N. "Optical and electrical properties of II-VI wide gap semiconducting barium sulfide" Proceedings of SPIE (1992), 1523 (Conf. Phys. Technol. Semicond. Devices Integr. Circuits, 1992), 608-12.
4. ^ F. Licetus, Litheosphorus, sive de lapide Bononiensi lucem in se conceptam ab ambiente claro mox in tenebris mire conservante, Utini, ex typ. N. Schiratti, 1640. See http://www.chem.leeds.ac.uk/delights/texts/Demonstration_21.htm
5. ^ "Lapis Boloniensis". www.zeno.org. http://www.zeno.org/Lemery-1721/A/Lapis+Boloniensis. 
6. ^ Lemery, Nicolas (1714). Trait℗e universel des drogues simples. http://books.google.de/books?id=K25AAAAAcAAJ&pg=PA458#v=onepage&q&f=false. 
7. ^ Ozanam, Jacques; Montucla, Jean Etienne; Hutton, Charles (1814). Recreations in mathematics and natural philosophy ... http://books.google.de/books?id=jAYAAAAAQAAJ&pg=PA411. 
8. ^ Marggraf, Andreas Sigismund (1767). Chymische Schriften. http://books.google.de/books?id=Obc5AAAAcAAJ&pg=PA113.