Disulfur monoxide or sulfur suboxide is an inorganic compound with formula S2O. It is one of the lower sulfur oxides. It is a colourless gas and condenses to give a pale coloured solid that is unstable at room temperature. It is a bent molecule with an S-S-O angle of 117.88°, S-S bond length of 188.4pm, and S-O bond length of 146.5pm.

CAS：20901-21-7
中文别名：二硫化一氧;
英文别名：disulfur oxide;S2O;sulfur suboxide;Sulfuroxide;
分子式：OS2
分子量：80.1294
精确质量：79.9391
Psa：81.25
Logp：1.1776

外观与性状：一般为无色气体，冷冻后转变为浅色固体，室温下不稳定
密度：1.55g/cm3
折射率：1.636