Q8 · CSIR NET Chemistry, December 2019
Paper: CSIR NET December 2019 · Subject: Inorganic Chemistry · Chapter: Inorganic Spectroscopy · Topic: Inorganic Spectroscopy – General · Marks: 2 · Difficulty: Hard
For the complex shown below in non-fluxional state, the expected $^{31}\mathrm{P}\{^{1}\mathrm{H}\}$ NMR resonance(s) is/are [$^{31}\mathrm{P}$ = I = 1/2] 

(a)one singlet
(b)one doublet
(c)two Singlets
(d)two doublets
Answer
Answer: D ✓ checked by 4AB · confidence high
The source book printed no answer; this one was worked out and checked — see the explanation.
Explanation
The two phosphorus atoms are chemically inequivalent and couple with each other, so the ³¹P{¹H} spectrum shows two doublets.
Study loop for Inorganic Spectroscopy