Arsonic acid is the simplest of the

arsonic acids Arsonic acids are a subset of organoarsenic compounds defined as oxyacids where a pentavalent arsenic atom is bonded to two hydroxyl groups, a third oxygen atom (this one with a double bond), and an organic substituent. The salts/conjugate bases of ...

. It is a hypothetical compound, although the

tautomer Tautomers () are structural isomers (constitutional isomers) of chemical compounds that readily interconvert. The chemical reaction interconverting the two is called tautomerization. This conversion commonly results from the relocation of a hydr ...

ic arsenious acid (As(OH)₃) is well established. In contrast to the instability of HAsO(OH)₂, the phosphorus compound with analogous stoichiometry exists as the tetrahedral tautomer. Similarly, organic derivatives such as

phenylarsonic acid Phenylarsonic acid is the chemical compound with the formula C6H5AsO(OH)2, commonly abbreviated PhAsO3H2. This colourless solid is an organic derivative of arsenic acid, AsO(OH)3, where one OH group has been replaced by a phenyl group. The compou ...

are tetrahedral with pentavalent central atom. There are similar acids that are the same except for having different pnictogens. The phosphorus equivalent is phosphonic acid.

References

Arsonic acids Hypothetical chemical compounds {{theoretical-chem-stub