Dihydroxydisulfane
Dihydroxydisulfane or hypodithionous acid is a reduced sulfur oxyacid with sulfur in a formal oxidation state of +1. The structural formula is HOSSOH, with all atoms arranged in a chain. It is an isomer of thiosulfurous acid but is lower in energy. Other isomers include HOSSH, HOSOH, and HS2SH. 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.
Dihyroxydisulfane may exist in an equilibrium with thiosulfurous acid.
Organic derivatives such as dimethoxydisulfane, diaceto disulfide, and bis disulfide also exist.
The conjugate bases are called disulfanediolate and disulfanediolate.Properties
Calculations predict that the S−S bond length is 2.013 Å, O−S bond length is 1.645 Å, H−O bond length is 0.943 Å.Related compounds
Related compounds include the isoelectronic substances hydrogen tetroxide HOOOOH, hydroxotrisulfane HOSSSH, HSOSSH, and tetrasulfane HSSSSH.
