Pyrosulfate

In chemistry, disulfate or pyrosulfate is the anion with the molecular formula S2O2−7.

[1] It has a dichromate-like structure and can be visualised as two corner-sharing SO4 tetrahedra, with a bridging oxygen atom.

Disulfate is the conjugate base of the hydrogen disulfate (hydrogen pyrosulfate) ion HS2O−7, which in turn is the conjugate base of disulfuric acid (pyrosulfuric acid).

For example, dodecyl alcohol is sulfated using sulfur trioxide.

The reaction proceeds by initial formation of the pyrosulfate: Several million tons are produced annually.