Question

Why is accidental overlap of signals much more common in H-1 NMR than in C-13 NMR?

Answer 1

See explanation

Step-by-step explanation:

Accidental overlap of signals are common in H-1 NMR than in C-13 NMR for the following reasons;

1) 13C has a very low natural abundance compared to H-1

2) 13C nucleus is s many times lesser in NMR sensitivity than H-1 nucleus.

3) As a result of its low abundance, 13C-13C coupling is not common.

4) Longer relaxation times do not give room for integrations.

5) Peaks in 13C spectra mainly consists of single lines.

As a result of all these, 13C-NMR spectra take longer to acquire than H-NMR. Hence, accidental overlap of signals is much more common in H-1 NMR than in C-13 NMR.