Thiosulfurous acid (HS-S(=O)-OH) or sulfurothionous O,O acid is a low oxidation state (+1) sulfur acid [ (+1) is the average oxidation state of the two structurally different sulfur atoms . The exterior atom has a oxidation number of (-1) while the central sulfur atom has the oxidation state of (+3) ]. It is termed a disulfur(I) acid. It is the equivalent acid for disulfur monoxide. Thiosulfurous acid is formed by reacting hydrogen sulfide and sulfur dioxide at room temperature. The thiosulfurous acid molecule is unstable when condensed, reacting with itself.

CAS：15060-43-2
中文别名：
英文别名：Thioschweflige Saeure;
分子式：H2O2S2
分子量：98.1447
精确质量：97.9496
Psa：91.76
Logp：1.3138