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 → H2S2O2Dihyroxydisulfane 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 HS2O−2 and hypodithionite S2O2−2.
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.7
Related compounds
Related compounds include the isoelectronic substances hydrogen tetroxide HOOOOH, hydroxotrisulfane HOSSSH, HSOSSH, and tetrasulfane HSSSSH.
References
Schmidt, Heinar; Steudel, Ralf; Suelzle, Detlev; Schwarz, Helmut (March 1992). "Sulfur compounds. 148. Generation and characterization of dihydroxy disulfide, HOSSOH: the chainlike isomer of thiosulfurous acid". Inorganic Chemistry. 31 (6): 941–944. doi:10.1021/ic00032a004. /wiki/Doi_(identifier) ↩
Makarov, Sergei V.; Makarova, Anna S.; Silaghi-Dumitrescu, Radu (2014). "Sulfoxylic and thiosulfurous acids and their dialkoxy derivatives". PATAI's Chemistry of Functional Groups. John Wiley & Sons. pp. 266–273. doi:10.1002/9780470682531.pat0829. ISBN 9780470682531. 9780470682531 ↩
Patai, Saul (2015-04-20). The Chemistry of Peroxides. John Wiley & Sons. ISBN 9781118412718. 9781118412718 ↩
Baumeister, Edgar; Oberhammer, Heinz; Schmidt, Heinar; Steudel, Ralf (December 1991). "Gas phase structure and vibrational spectra of dimethoxysulfane (CH3O)2S". Heteroatom Chemistry. 2 (6): 633–641. doi:10.1002/hc.520020605. /wiki/Doi_(identifier) ↩
Du, Lin; Yao, Li; Ge, Maofa (November 2007). "He I Photoelectron Spectroscopy and Theoretical Investigation on Diaceto Disulfide, CH3C(O)OSSOC(O)CH3". The Journal of Physical Chemistry A. 111 (46): 11787–11792. Bibcode:2007JPCA..11111787D. doi:10.1021/jp075164h. PMID 17958404. /wiki/Bibcode_(identifier) ↩
Zeng, Xiaoqing; Ge, Maofa; Sun, Zheng; Wang, Dianxun (May 2006). "Bis(trifluoroaceto) Disulfide (CF3C(O)OSSOC(O)CF3): A HeI Photoelectron Spectroscopy and Theoretical Study". The Journal of Physical Chemistry A. 110 (17): 5685–5691. Bibcode:2006JPCA..110.5685Z. doi:10.1021/jp061050e. PMID 16640363. /wiki/Bibcode_(identifier) ↩
Patai, Saul (2004). The Chemistry of Peroxides. Vol. 3 part 1. John Wiley & Sons. p. 296. ISBN 9781118412718. 9781118412718 ↩