Article · Wikipedia archive · Last revised Jun 9, 2026

Arsonium

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 cation, such as arsonium bromide and arsonium iodide, which can be synthesized by reacting arsine with hydrogen bromide or hydrogen iodide. Or more commonly, as organic derivative such as the quaternary arsonium salts Ph4As+Cl− and the zwitterionic compound arsenobetaine.

Last revised
Jun 9, 2026
Read time
≈ 1 min
Length
175 w
Citations
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Source
Arsonium
source ↗
Ball-and-stick model version of the arsonium ion
source ↗
Names
Systematic IUPAC name
Arsonium
Identifiers
3D model (JSmol)
ChEBI
ChemSpider
322800
  • InChI=1S/AsH4/h1H4/q+1
    Key: VUEDNLCYHKSELL-UHFFFAOYSA-N
  • [AsH4+]
Properties
AsH+
4
Molar mass 78.954 g·mol−1
Conjugate base Arsine
Structure
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).
Structure of quaternary arsonium compound arsenobetaine. source ↗

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+
4
Br
) and arsonium iodide (AsH+
4
I
), 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
4
As+
Cl
(CAS: 123334-18-9 , hydrate form) and the zwitterionic compound arsenobetaine.

References

References

  1. Muñoz-Hernández, M. Á. (2006). Arsenic: Inorganic Chemistry. Encyclopedia of Inorganic Chemistry. pp 4. DOI: 10.1002/0470862106.ia013