Functionalized Fluorophosphonium Ions

Efforts to prepare an elusive donor-free phosphenium ion, [R P] , led us to synthesize functionalized fluorophosphonium cations of the type [R P(F)X] (X=SiEt , H, F), which were obtained from the related neutral fluorophosphines R PF and R PF upon protonation and reaction with solvated [Et Si] ions (R=2,6-Mes C H ). The hypothetical reductive elimination of [R P(F)SiEt ] and [R P(F)H] affording [R P] , Et SiF and HF, respectively, was calculated to be endothermic by 40.1 and 190.6 kJ mol .