The arsonium cation is a positively charged polyatomic ion with the chemical formula AsH⁺
₄. An arsonium salt is a salt containing either the arsonium (AsH⁺
₄) cation, such as arsonium bromide (AsH⁺
₄Br⁻
) and arsonium iodide (AsH⁺
₄I⁻
), which can be synthesized by reacting arsine with hydrogen bromide or hydrogen iodide.^[1] Or more commonly, as organic derivative such as the quaternary arsonium salts Ph
₄As⁺
Cl⁻
(CAS: 123334-18-9 , hydrate form) and the zwitterionic compound arsenobetaine.

Arsonium

Names
Systematic IUPAC name Arsonium
Identifiers
CAS Number	53250-40-1
3D model (JSmol)	Interactive image
ChEBI	CHEBI:30272
ChemSpider	4574016
Gmelin Reference	322800
PubChem CID	5460506
CompTox Dashboard (EPA)	DTXSID10420093
InChI InChI=1S/AsH4/h1H4/q+1 Key: VUEDNLCYHKSELL-UHFFFAOYSA-N
SMILES [AsH4+]
Properties
Chemical formula	AsH+ 4
Molar mass	78.954 g·mol−1
Conjugate base	Arsine
Structure
Molecular shape	Tetrahedral
Related compounds
Related compounds	ammonium phosphonium
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). Infobox references