Chemicals and Drugs

Onium Compounds

Ions with the suffix -onium, indicating cations with coordination number 4 of the type RxA+ which are analogous to QUATERNARY AMMONIUM COMPOUNDS (H4N+). Ions include phosphonium R4P+, oxonium R3O+, sulfonium R3S+, chloronium R2Cl+

National Library of MedicineMedical Subject Headings2026

Structured Summary

Abstract

Ions with the suffix -onium, indicating cations with coordination number 4 of the type RxA+ which are analogous to QUATERNARY AMMONIUM COMPOUNDS (H4N+). Ions include phosphonium R4P+, oxonium R3O+, sulfonium R3S+, chloronium R2Cl+

MeSH Record

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MeSH Record

Synonyms

1 entry terms
  • Compounds, Onium

MeSH Record

Aspects Covered

24 allowable subheadings

Indexed with the subheadings administration & dosage, adverse effects, agonists, analysis, antagonists & inhibitors, blood, cerebrospinal fluid, chemical synthesis, chemistry, classification, economics, history, immunology, isolation & purification, metabolism, pharmacokinetics, pharmacology, poisoning, radiation effects, standards, supply & distribution, therapeutic use, toxicity, urine.

MeSH Record

History Note

68

MeSH Hierarchy

Tree Number

  1. D02w.675w

AMA Style

References

  1. National Library of Medicine. Onium Compounds. Medical Subject Headings (MeSH). 2026. Unique ID D009861. http://id.nlm.nih.gov/mesh/2026/D009861
  2. Onium Compounds. In: Wikipedia. https://en.wikipedia.org/wiki/Onium_ion
  3. Onium Compounds. In: Wikidata. https://www.wikidata.org/wiki/Q341409