Tetraphenylphosphonium bromide is a quaternary phosphonium salt mainly used in pharmaceuticals, as accelarator for fluoroelastomers , adhesion promotor for fluoroelastomers and curative of polyacrylate polymers which extends the shelf life of the compound and decreases the mould fouling.
Phosphonium iodide is a chemical compound with the formula PH ₄I. It is an example of a salt containing an unsubstituted phosphonium cation. Phosphonium iodide is commonly used as storage for phosphine and as a reagent for substituting phosphorus into organic molecules