Multiple magnetic resonance studies of some para-substituted derivatives of triphenyl phosphine

¹⁹F and ³¹P decoupling experiments are used to simplify the proton spectra of para-substituted derivatives of triphenyl phosphine, prior to ¹H-{¹H} tickling experiments. ³J(³¹P…?H) and ⁴J(³¹P…?H) are positive, and ⁵J(³¹P…?¹⁹F) is negative in the trivalent phosphorus derivatives, and all become more positive as the valency of the phosphorus atom is increased. A triple resonance experiment is used to show that ⁷J(³¹P…?H) in p-CH₃C₆H₄CH₂P^⊕(C₆H₅)₃] is negative. The double resonance technique is used to relate the ³¹P chemical shifts to the tetramethylsilane resonant frequency.