Boron sulfide is the
chemical compound
A chemical compound is a chemical substance composed of many identical molecules (or molecular entities) containing atoms from more than one chemical element held together by chemical bonds. A molecule consisting of atoms of only one element ...
with the
formula B
2S
3. 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, B
2S
3 reacts with water, including atmospheric moisture to release
H2S. Thus, samples must be handled under anhydrous conditions.
Like the boron oxides, B
2S
3 readily forms
glass
Glass is a non-crystalline, often transparent, amorphous solid that has widespread practical, technological, and decorative use in, for example, window panes, tableware, and optics. Glass is most often formed by rapid cooling ( quenching ...
es when blended with other sulfides such as
P4S10. Such glasses absorb lower frequencies of
Infra-red energy relative to conventional
borosilicate
Borosilicate glass is a type of glass with silica and boron trioxide as the main glass-forming constituents. Borosilicate glasses are known for having very low coefficients of thermal expansion (≈3 × 10−6 K−1 at 20 °C), ma ...
glasses.
B
2S
3 converts
ketones into the corresponding
thiones. For example, the conversion of
benzophenone
Benzophenone is the organic compound with the formula (C6H5)2CO, generally abbreviated Ph2CO. It is a white solid that is soluble in organic solvents. Benzophenone is a widely used building block in organic chemistry, being the parent diarylket ...
to its thione proceeds as follows:
: + 3 → + 3
In practice, B
2S
3 would be used in excess.
Synthesis
Among other methods Diboron Trisulfide can be obtained by the reaction of iron or manganese
boride A boride is a compound between boron and a less electronegative element, for example silicon boride (SiB3 and SiB6). The borides are a very large group of compounds that are generally high melting and are covalent more than ionic in nature. Some bo ...
with
hydrogen sulfide at temperatures of 300 °C.
:2 FeB + 4 H
2S → B
2S
3 + FeS + 4 H
2
The first synthesis was done by
Jöns Jakob Berzelius
Jöns is a Swedish given name and a surname.
Notable people with the given name include:
* Jöns Jacob Berzelius (1779–1848), Swedish chemist
* Jöns Budde (1435–1495), Franciscan friar from the Brigittine monastery in NaantaliVallis Grati ...
in 1824 by direct reaction of amorphous
boron with
sulfur vapor.
:2 B + 3 S → B
2S
3
Another synthesis was favoured by
Friedrich Wöhler and
Henri Etienne Sainte-Claire Deville first published in 1858, starting from boron and
hydrogen sulfide.
:2 B + 3 H
2S → B
2S
3 + 3 H
2
Structure
The boron atoms in B
2S
3 are trigonal planar, and are arranged in B
3S
3 and B
2S
2 rings with bridging S atoms forming a layer structure with an interlayer distance of 355 pm. This is different from
boron trioxide
Boron trioxide or diboron trioxide is the oxide of boron with the formula . It is a colorless transparent solid, almost always glassy (amorphous), which can be crystallized only with great difficulty. It is also called boric oxide or boria. It h ...
which has a three dimensional structure.
The molecular, monomeric, form of B
2S
3 has a planar V shape with the central B-S-B angle of approximately 120°.
References
{{Sulfides
Boron compounds
Sulfides