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Phosphonium ion Structure of PH + 4, the parent phosphonium cation. In chemistry, the term phosphonium (more obscurely: phosphinium) describes polyatomic cations with the chemical formula PR + 4 (where R is a hydrogen or an alkyl, aryl, organyl or halogen group). These cations have tetrahedral structures.
A variety of phosphonium salts can be prepared by alkylation and arylation of organophosphines: PR 3 + R'X → [PR 3 R' +]X −. The methylation of triphenylphosphine is the first step in the preparation of the Wittig reagent.
Phosphonium iodide is a powerful substitution reagent in organic chemistry; for example, it can convert a pyrilium into a phosphinine via substitution. [3] In 1951, Glenn Halstead Brown found that PH 4 I reacts with acetyl chloride to produce an unknown phosphine derivative, possibly CH 3 C(=PH)PH 2 ·HI .
Because phosphonium ylides are seldom isolated, the byproduct(s) generated upon deprotonation essentially plays the role of an additive in a Wittig reaction. As a result, the choice of base has a strong influence on the efficiency and, when applicable, the stereochemical outcome of the Wittig reaction.
Phosphonates feature tetrahedral phosphorus centers. They are structurally closely related to (and often prepared from) phosphorous acid. [3]Phosphonic acids and derivatives are chemically and structurally related to phosphorous acid.
Phosphenium ions, not to be confused with phosphonium or phosphirenium, are divalent cations of phosphorus of the form [PR 2] +. Phosphenium ions have long been proposed as reaction intermediates. Phosphenium ions have long been proposed as reaction intermediates.
Triphenylphosphine (IUPAC name: triphenylphosphane) is a common organophosphorus compound with the formula P(C 6 H 5) 3 and often abbreviated to P Ph 3 or Ph 3 P. It is versatile compound that is widely used as a reagent in organic synthesis and as a ligand for transition metal complexes, including ones that serve as catalysts in organometallic chemistry.
Phosphine (IUPAC name: phosphane) is a colorless, flammable, highly toxic compound with the chemical formula P H 3, classed as a pnictogen hydride.Pure phosphine is odorless, but technical grade samples have a highly unpleasant odor like rotting fish, due to the presence of substituted phosphine and diphosphane (P 2 H 4).