S2O32−\mathrm{S}_{2} \mathrm{O}_{3}{ }^{2-}S2O32−
I2\mathbf{I}_{2}I2
I−\mathrm{I}^{-}I−
S4O62−\mathrm{S}_{4} \mathrm{O}_{6}{ }^{2-}S4O62−