Table 3 Deprotonation trends for neutral and anionic As(III) oxy- and thio-species. Emboldened species are likely to dominate at circum-neutral pH

0

As(OH) ₃ ⁰

As(OH)₂O^-

As(OH)O₂^2-

AsO₃^3-

1

As(OH) ₂ (SH) ⁰

As(OH) ₂ S ^-

AsO₂HS^2-

AsO₂S^3-

2

As(OH)(SH)₂⁰

As(OH)S ₂ H ^-

As(OH)S ₂ ^2-

AsOS₂^3-

3

As(SH)₃

AsS₃H₂^-

AsS ₃ H ^2-

AsS₃^3-

4

As(SH)₄H⁰

As(SH) ₄

As(SH)₃S^2-

As(SH)₂S₂^3-