(a) In the 1H NMR spectrum of compound 4.21, there is a triplet at δ 3.60 ppm (.J 10.4 Hz)...

(a) In the 1H NMR spectrum of compound 4.21, there is a triplet at δ 3.60 ppm (.J 10.4 Hz). Assign the signal and explain the origin of the coupling. What would you observe in the 31P{1H} NMR spectrum of compound 4.21?

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(b) Figure 4.38 shows the solid state structure of a phosphorus-containing cation. The 3IP NMR spectrum of a CDC13 solution of the [CF3S03]– salt was recorded. How many signals (ignore spin-spin

Fig. The structure of tlie [(PCMc3)3Me]+ cation in the salt [(PCMe3)3Me][CF3S03] determined by X-ray diffraction [N. Burford et al. (2005) Angew Chem. Int. Ed., vol. 44, p. 6196]. Colour code: P, orange; C, grey; H, while. coupling) would you expect to see in the spectrum, assuming that the solid slate structure is retained in solution?