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Updated: Jun 22, 2026

Preparation and Reactivity of a Triphosphenium Bromide Salt: A Convenient and Stable Source of Phosphorus(I)
Published on: November 22, 2016
The tris(trifluoromethyl)methyl phosphonium ion, P(CF(3))(3)CH(3)(+), preparation and structure
Oleg Shyshkov1, Uwe Dieckbreder, Thomas Drews
1Institute of Inorganic & Physical Chemistry, University of Bremen, D-28334 Bremen, Germany.
Abstract:
The P(CF(3))(3)CH(3)(+) ion is synthesized as P(CF(3))(3)CH(3)(+)AsF(6)(-) by methylation in a MeF/SO(2)/AsF(5) system or as P(CF(3))(3)CH(3)(+)Sb(2)F(11)(-) in a MeF/HF/SbF(5) system at low temperatures. In contrast to (CF(3))(3)(CH(3))P(+)AsF(6)(-), P(CF(3))(3)CH(3)(+)Sb(2)F(11)(-) is a stable, colorless crystalline solid. A crystal structure determination shows the presence of a slightly distorted tetrahedral phosphonium cation with P-C(F) distances of 188.1-188.7(4) and a P-C(H) bond length of 176.7(4) pm. The phosphonium salt (CF(3))(3)(CH(3))P(+)AsF(6)(-) was also obtained by abstraction of a fluoride ion from the anion [(CF(3))(3)(CH(3))PF(2)](-) salt using AsF(5).
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