Question

What does decoupling in NMR mean?

Answer 1

Hint: Different functional groups are distinguishable with the help of NMR spectroscopy.
Decoupling can help in the identification of compound structures.

Complete answer:
NMR or Nuclear Magnetic Resonance spectroscopy is a technique of spectroscopy used for the observation of magnetic fields around atomic nuclei. A sample is placed inside a magnetic field. The excitation of the sample nuclei produces an NMR signal. The sample is excited with the use of radio waves. This excitation is detected by sensitive radio receivers.
The principle of NMR involves the following steps:
- The magnetic nuclear spin polarization is applied in a constant magnetic field.
- Radio frequency pulse is the deviation of this magnetic nuclear spin due to a weak, oscillating magnetic field.
- This deviation results in the detection and study of the electromagnetic waves emitted by the atomic nuclei.
NMR decoupling is a technique used in NMR spectroscopy where the sample nuclei is exposed to a range of frequencies to eliminate the effect of coupling between the nuclei.
Nuclear Magnetic Resonance decoupling eliminates the division of signals between the exposed nuclei and the other nuclei.
Homonuclear decoupling is the exposure of a range of frequencies to nuclei that are the same isotopes. Heteronuclear decoupling is the exposure of a range of frequencies to nuclei that are of a different isotope than the sample nuclei.

Note:
NMR is used by biochemists for the identification of proteins. NMR showcases detailed information of the physical and chemical characteristics of molecules. The structure, state of reaction and chemical environment of molecules can be studied through NMR.