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.
Boron sesquisulfide, Diboron trisulfide
3D model (JSmol)
CompTox Dashboard (EPA)
|Molar mass||117.80 g/mol|
|Density||1.55 g/cm3, solid|
|Melting point||563 °C (1,045 °F; 836 K)|
|Boiling point||decomposes at high T|
|Solubility||soluble in ammonia|
|monoclinic, mP40, SpaceGroup = P21/c, No. 14|
|B: planar, sp2|
Heat capacity (C)
|111.7 J/mol K|
|327 J/mol K|
Std enthalpy of
|Occupational safety and health (OHS/OSH):|
|source of H2S|
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
(what is ?)
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.
In practice, B2S3 would be used in excess.
The boron atoms in B2S3 are trigonal planar, and are arranged in B3S3 and B2S2 rings with bridging S atoms forming a layer structure with an interlayer distance of 355 pm. This is different from boron trioxide which has a three dimensional structure.
The molecular, monomeric, form of B2S3 has a planar V shape with the central B-S-B angle of approximately 120°.