The phosphines R(RF)2P (RF= CF3, R = Me, Buⁿ, Buⁱ, Ph; RF= C3F7, R = Buⁿ, Ph) and Bu2 ⁿ(CF3)P, and the phosphinous chloride Bu(CF3)PCl, have been made from the chlorides (RF)2PCl or RFPCl2 and organolithium compounds in etherâ hexane at â 78°. The phosphines R2(C3F7)P (R = Et, Ph, CF3) and CF3(C3F7)2P have been made from the compounds R2PCl or CF3PCl2 and heptafluoropropyl-lithium. The phosphine (CF3)2(C3F7)P was oxidised by nitrogen dioxide to the phosphine oxide (CF3)2(C3F7)PO, which was hydrolysed by water. Infrared and n.m.r. spectra are discussed. The hydrolyses of the compounds R(CF3)2P with alkali in waterâ ethanol follow second-order kinetics, and rate constants at 25° decrease in the order R = Buⁿ > Buⁱ > Ph. CF3 was cleaved more easily than C3F7 from the unsymmetrical phosphine (CF3)2(C3F7)P, but from the phosphine oxide (CF3)2(C3F7)PO and from perfluoroalkyl phosphonites and phosphinates, the rate of cleavage of CF3 was similar to that of C3F7.