Dihydroxydisulfane

Dihydroxydisulfane
Names
Other names
Hydrogen disulfanediolate; Dihydroxidodisulfur; Disulfanediol
Identifiers
3D model (JSmol)
ChEBI
ChemSpider
164020
  • InChI=1S/H2O2S2/c1-3-4-2/h1-2H
    Key: JARODAOQOSWMRF-UHFFFAOYSA-N
  • OSSO
Properties
H2O2S2
Molar mass 98.13 g·mol−1
Conjugate base Disulfanediolate
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
Infobox references

Dihydroxydisulfane or hypodithionous acid is a reduced sulfur oxyacid with sulfur in a formal oxidation state of +1, but the valence of sulfur is 2. The structural formula is HO−S−S−OH, with all atoms arranged in a chain. It is an isomer of thiosulfurous acid but is lower in energy. Other isomers include HOS(=O)SH, HOS(=S)OH, and HS(=O)2SH. Disulfur monoxide, S2O, can be considered as the anhydride. Unlike many of these other reduced sulfur acids, dihydroxydisulfane can be formed in a pure state by reacting hydrogen sulfide with sulfur dioxide at −70 °C in dichlorodifluoromethane.

H2S + SO2 → H2S2O2

Dihyroxydisulfane may exist in an equilibrium with thiosulfurous acid.

Organic derivatives such as dimethoxydisulfane, diaceto disulfide, and bis(trifluoroaceto) disulfide also exist.

The conjugate bases are called disulfanediolate HS
2
O
2
and hypodithionite S
2
O2−
2
.