Question

4.40 The structure of [P;Bru] is shown in diagram 4.17. Account for the fact that the "'P NMR spectrum of this cation at 203 K consists of a doublet of triplets (J 321 Hz, 149 Hz), a triplet of triplets (J 321 Hz, 26 Hz) and a triplet of doublets (J 149 Hz, 26 Hz).

Answer 1

- PO70 16 MBX - se By, 70 31 p NMR W I = + (magnetic quantum number) 0 In [PsBrz], one 31p de coupled with two non-equivalent NMR activa nuclei environment. In this situation, the coupling from non-equivalent nucli, combines to give more complex signal splitting fathering . Hmo, these 39p Abisonments are in the ratio of 2:1:2). coupling to two non-equivalent 31p gives a "toi flet" and coupling to on Jip gives doublet". Thus, the coupling combines to give a doublet of trißlet? (Jpp = 321 H2 4199 Me) coupling to showo non-equivalent 31p gives a fiflet' and coufiling to two 31p gives a "triglet": Thus, the coupling combines to give a riflet of triflet". (Jp = 34 H 4 26 H2) coupling to on 3!p gives a doublect and coufiling to two 31p gives a tilld. This, the coufting combines to give a "triplet of doublet". (Jp = 149 & 26H2) © © E