H2SO3as

H2SO3as is a proposed, but not established, chemical species. It would nominally consist of hydrogen, sulfur, oxygen and arsenic in the empirical formula H2SO3As. No peer-reviewed reports confirm its existence or characterize its properties. The name situates it among oxo- and oxo-arsenic acids, but it should not be conflated with known species such as sulfurous acid H2SO3 or arsenous acid H3AsO3.

Composition and possible valence: The formula could describe a neutral molecule containing a sulfur-centered oxoacidity with an arsenic substituent or a covalent adduct between sulfurous and arsenic-containing fragments. Multiple structural isomers are conceivable, but none have been experimentally demonstrated.

Synthesis and stability: The compound has not been synthesized or isolated in standard conditions. Hypothetical preparation routes would require dehydrating or condensing sulfurous acid derivatives with arsenic oxo species under carefully controlled conditions, but such routes remain speculative. The instability of high-oxidation-state sulfur and arsenic centers can lead to rapid hydrolysis or disproportionation.

Properties and reactivity: In the absence of data, predicted properties are uncertain. It would be expected to be highly acidic and potentially reactive toward water and bases; arsenic-containing oxoacids are typically toxic and require cautious handling. Any real compound of this formula would likely exist only as transient species or in matrix/isolation at low temperature.

Significance and see also: H2SO3as is primarily of theoretical interest for considerations of heteroatom substitution in oxoacids. Related concepts include sulfurous acid (H2SO3), arsenous acid (H3AsO3), and mixed oxoacids or metal complexes that incorporate both sulfur and arsenic centers.