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Boron sulfide

Boron sulfide
IUPAC name Boron sulfide
Other names Boron trisulfide
CAS number 12007-33-9
Molecular formula B2S3
Molar mass 117.80 g/mol
Appearance colorless crystals
Density 1.55 g/cm3, solid
Melting point

563 °C

Boiling point

decomposes at high T

Solubility in water decomposes
Crystal structure monoclinic
B: planar, sp2
Main hazards source of H2S
Related Compounds
Related compounds BCl3
Lawesson's reagent
Except where noted otherwise, data are given for
materials in their standard state
(at 25 °C, 100 kPa)

Infobox disclaimer and references

Boron sulfide is the chemical compound with the formula B2S3. This polymeric material that has been of interest as a component of “high-tech” glasses and as a reagent for preparing organosulfur compounds. Like the sulfides of silicon and phosphorus, B2S3 reacts with water, including atmospheric moisture to release H2S. Thus, samples must be handled under anhydrous conditions.

Like the boron oxides, B2S3 readily forms glasses when blended with other sulfides such as P4S10. Such glasses absorb lower frequencies of Infra-red energy relative to conventional borosilicate glasses.

B2S3 converts ketones into the corresponding thiones. An idealized equation for such a transformation is:

B2S3 + 3 (C6H5)2C=O → B2O3 + 3 (C6H5)2C=S

In practice, B2S3 would be used in excess.[1]


Besides other methods the boron sulfide can be obtained by the reaction of iron or manganese boride with hydrogen sulfide at temperatures of 300°C.[2]

2FeB + 4H2S → B2S3 + FeS

The first synthesis was done by Jöns Jakob Berzelius in 1824 by direct reaction of amorphous boron with sulfur vapor.

2B + 3S → B2S3

Another synthesis was favoured by Friedrich Wöhler and Henri Etienne Sainte-Claire Deville first published in 1858, starting from boron and hydrogen sulfide.[3][4]

2B + 3H2S → B2S3 +H2


  1. ^ Sato, R. "Boron trisulfide" in Encyclopedia of Reagents for Organic Synthesis (Ed: L. Paquette) 2004, J. Wiley & Sons, New York. DOI: 10.1002/047084289.
  2. ^ J. Hoffmann (1908). "Synthese von Borsulfid aus Ferro- und Manganbor". Zeitschrift für anorganische Chemie 59 (1): 127-135. doi:10.1002/zaac.19080590116.
  3. ^ F. Wöhler and H. E. S.-C. Deville (1858). "Neue Beobachtungen über das Bor und einige seiner Verbindungen". Liebigs Annalen 105 (1): 67-73. doi:10.1002/jlac.18581050109.
  4. ^ F. Wöhler and H. E. S.-C. Deville (1858). "Du Bore". Annales de chimie et de physique 52: 62-93.
This article is licensed under the GNU Free Documentation License. It uses material from the Wikipedia article "Boron_sulfide". A list of authors is available in Wikipedia.
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