 | |
| Names | |
|---|---|
| IUPAC name Boron sulfide | |
| Other names Boron sesquisulfide, Diboron trisulfide | |
| Identifiers | |
3D model (JSmol) | |
| ChemSpider | |
| ECHA InfoCard | 100.031.355 |
| EC Number |
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| |
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| Properties | |
| B2S3 | |
| Molar mass | 117.80 g/mol |
| Appearance | colorless crystals |
| Density | 1.55 g/cm3, solid |
| Melting point | 563 °C (1,045 °F; 836 K) |
| Boiling point | decomposes at high T |
| decomposes | |
| Solubility | soluble inammonia |
| Structure | |
| monoclinic,mP40, SpaceGroup = P21/c, No. 14 | |
| B: planar, sp2 | |
| Thermochemistry | |
| 111.7 J/mol K | |
Std molar entropy(S⦵298) | 327 J/mol K |
Std enthalpy of formation(ΔfH⦵298) | −240.6 kJ/mol |
| Hazards | |
| Occupational safety and health (OHS/OSH): | |
Main hazards | source of H2S |
| GHS labelling: | |
   | |
| Danger | |
| H225,H260,H301,H311,H315,H318,H335 | |
| P210,P223,P231+P232,P280,P302+P352,P303+P361+P353,P305+P351+P338,P312,P402+P404,P405 | |
| NFPA 704 (fire diamond) | |
| Flash point | 18 °C (64 °F; 291 K) |
| Safety data sheet (SDS) | trc-canada.com |
| Related compounds | |
Related compounds | BCl3 Lawesson's reagent |
Except where otherwise noted, data are given for materials in theirstandard state (at 25 °C [77 °F], 100 kPa). | |
Boron sulfide is thechemical compound with theformula B2S3. It is a white,moisture-sensitive solid. It has a polymeric structure. The material has been of interest as a component of "high-tech" glasses and as a reagent for preparing organosulfur compounds. It is the parent member of thethioborates.
Like the sulfides of silicon and phosphorus, B2S3 reacts with traces of water, including atmospheric moisture to releaseH2S. This hydrolysis is described by the following idealized equation:
B2S3 readily formsglasses when blended with other sulfides such asP4S10. Such glasses do not absorb mid-frequencies ofInfra-red energy relative to conventionalborosilicate glasses. Some of these ternary phases that are fast ion conductors.[2]
B2S3 convertsketones into the correspondingthiones. For example, the conversion ofbenzophenone to itsthione proceeds as follows:
In practice, B2S3 would be used in excess.[3]
An early synthesis involved the reaction of iron and manganeseborides withhydrogen sulfide at temperatures of 300 °C. The conversion is shown for the monoborides in the following idealized equation:[4]
The first synthesis was done byJöns Jakob Berzelius in 1824 by direct reaction of amorphousboron withsulfur vapor.[5]
Another synthesis was favoured byFriedrich Wöhler andHenri Etienne Sainte-Claire Deville first published in 1858, starting from boron andhydrogen sulfide.[6][7]
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 fromboron trioxide which has a three dimensional structure.[8] The molecular, monomeric, form of B2S3 has a planar V shape with the central B-S-B angle of approximately 120°.[8]
