Phosphonium

In chemistry, the phosphonium cation is a positively charged polyatomic ion with the chemical formula PH₄⁺, resulting from protonation

Protonation

In chemistry, protonation is the addition of a proton to an atom, molecule, or ion. Protonation is possibly the most fundamental chemical reaction and is a step in many stoichiometric and catalytic processes. Some ions and molecules can undergo more than one protonation and are labeled...

 of phosphine

Phosphine

Phosphine is the common name for phosphorus trihydride , also known by the IUPAC name phosphane and, occasionally, phosphamine. It is a colorless, flammable gas with a boiling point of −88 °C at standard pressure...

. It has a molar mass

Molar mass

Molar mass, symbol M, is the mass of one mole of a substance . It is a physical property which is characteristic of each pure substance...

 of 35.01 g/mol.

Salts containing alkyl

Alkyl

In chemistry, an alkyl group is a hydrocarbon; typically an alkyl is a part of a larger molecule. The term is usually used loosely; there is no general formula for an alkyl group. In structural formulae, an alkyl group is represented with an R. Usually, alkyl groups resemble hydrocarbons, but...

 or aryl

Aryl

In the context of organic molecules, aryl refers to any functional group or substituent derived from a simple aromatic ring, may it be phenyl, thiophene, indolyl, etc . "Aryl" is used for the sake of abbreviation or generalization....

 groups attached to a positive phosphorus are referred to as phosphonium salt

Phosphonium salt

A phosphonium salt is a salt containing the phosphonium ion such as phosphonium iodide...

s. Alkyltriphenylphosphonium salts are widely used for the preparation of Wittig reagents for the Wittig reaction

Wittig reaction

The Wittig Reaction is a chemical reaction of an aldehyde or ketone with a triphenyl phosphonium ylide to give an alkene and triphenylphosphine oxide....

.

See also

• Ammonium
  Ammonium
  The ammonium cation is a positively charged polyatomic cation of the chemical formula NH. It has a formula weight of 18.05 and is formed by the protonation of ammonia...
  
   (NH₄⁺)
• Hydronium
  Hydronium
  In chemistry, hydronium is the common name for the aqueous cation , the simplest type of oxonium ion, produced by protonation of water. It is the positive ion present when an Arrhenius acid is dissolved in water, as Arrhenius acid molecules in solution give up a proton to the surrounding water...
  
   (H₃O⁺)
• Onium compounds
  Onium compounds
  Onium compounds are cations derived by the protonation of mononuclear parent hydrides of elements of the nitrogen family , chalcogen family , and halogen family , and similar cations derived by the substitution of hydrogen atoms in the former by other groups, such as organic radicals, or halogens,...