thumb|140px|right|class=skin-invert|Phosphonium ion 140px|right|thumb|Structure of , the parent phosphonium cation.
thumb|140px|right|class=skin-invert|Phosphonium ion 140px|right|thumb|Structure of , the parent phosphonium cation.
In chemistry, the term phosphonium (more obscurely: phosphinium) describes polyatomic cations with the chemical formula (where R is a hydrogen or an alkyl, aryl, organyl or halogen group). These cations have tetrahedral structures. The salts are generally colorless or take the color of the anions.
Discovered by embedding cosine similarity (sentence-transformers MiniLM, 384-dim).