Polythionic acid

Polythionic acid is an oxoacid which has a straight chain of sulfur atoms and has the chemical formula H₂S_nO₆ (n > 2). Trithionic acid (H₂S₃O₆), tetrathionic acid (H₂S₄O₆) are simple examples. The compounds of n < 80 are expected to exist, and those of n < 20 have already been synthesized. Dithionic acid (H₂S₂O₆) does not belong to polythionic acid due to the difference in the property.