The NMR spectra of some 3-coordinate phosphorus compounds containing chloromethyl and isopropyl groups

Analysis of the proton NMR spectra of Pr¹PCINMe₂ indicates magnetic non-equivalence of the methyl groups due to the adjacent asymmetric phosphorus atom. High temperatures, or the addition of chloride ion, induce an exchange reaction with inversion of configuration at phosphorus. The corresponding fluoride is configurationally stable at high temperatures. The compounds CICH₂PXNR₂ (X = Cl, F; R = Me, Et) have non-equivalent protons in the chloromethyl group. The two HCP coupling constants in the chlorides of this series are of opposite sign, whereas in the fluorides they are of the same sign.