Skip to main content
3 of 4
replaced http://chemistry.stackexchange.com/ with https://chemistry.stackexchange.com/

Why hydrogen disulfide and not hydrogen persulfide?

Recently, I was checking on this question and I was thinking of the name of the compound $\ce{FeS2}$. Later I checked the name in the answer to be iron disulfide. I found the following statement in the comments section:

Persulphide? Disulphide is ok here but per- not really.

The answerer actually named $\ce{FeS2}$ to be iron persulfide but later changed to iron disulfide after responding to the comment.

I checked the google and found the wikipedia article of marcasite and referred its name to be iron(II) disulfide. But why? Why not iron persulfide? It contains the $\ce{S2^2-}$ ion which is named disulfide anion. Why not persulfide anion (as per analogy to peroxide anion $\ce{O2^2-}$)?

In a group, compound names are named similarly to follow a certain fashion/trend. For e.g. methane, silane, germane (group 14). So, why $\ce{H2O2}$ is hydrogen peroxide and $\ce{H2S2}$ is hydrogen disulfide? Why it is not named hydrogen persulfide by analogy?

Related: Why is H2O2 named hydrogen peroxide?

Nilay Ghosh
  • 26.8k
  • 27
  • 95
  • 206