Determination of the 1H—31P coupling parameters in triphenylphosphine

From the single and double resonance 1H NMR spectra of triphenylphosphine, magnitudes and relative signs of the proton–proton and proton–phosphorus spin coupling constants were calculated. The values of these parameters were found to be nearly equal to those of the respective 1H—1H couplings in benzene. Results show that inter-ring proton–proton couplings are negligibly small.