What is homonuclear decoupling?

Homonuclear decoupling is when the nuclei being radio frequency (rf) irradiated are the same isotope as the nuclei being observed (analyzed) in the spectrum. Heteronuclear decoupling is when the nuclei being rf irradiated are of a different isotope than the nuclei being observed in the spectrum.

How is proton decoupling implemented?

Decoupling is achieved by a combination of a hard 180° pulse and band selective 180° pulses applied during a gradient of the same strength as used during excitation applied approximately every 1/3(3JHH). Acquisition and decoupling is alternated n times.

Is Homonuclear coupling removed?

After the 90° and magic angle (54.7°) proton pulses (see Figure 13) during the evolution period t1, the proton–proton dipolar couplings are removed by the homonuclear decoupling sequence (FSLG), whereas the remaining inhomogeneous interactions, that is, the chemical shift and the heteronuclear couplings, are averaged …

How is the 1H Homonuclear decoupling experiment done?

The traditional homonuclear decoupling experiment is done with weak, selective decoupling ( homonuclear decoupling) of one or a group of protons. Observation of the collapse of 1H fine splitting enables identification of through-bond coupled protons. This is an easy and quick experiment if only a few coupled partners are studied.

How is coupling, decoupling and Noe used in NMR?

Coupling, Decoupling and NOE in NMR Spectroscopy Experiment This experiment was developed by S.E. Van Bramerfor Chemistry 465at Widener University. Introduction: Coupling between nuclei is an important part of NMR. In proton NMR this coupling provides valuable information about how a molecule is connected.

How is coupling used in proton NMR spectroscopy?

In proton NMR this coupling provides valuable information about how a molecule is connected. Unfortunately, it also complicates the NMR spectrum. By selectively irradiating the coupled nuclei, it is possible to collapse the splitting patterns that are observed.

What’s the power limit for decoupling on nmr500?

Be very cautious when raising the power level for a long acquisition period with decoupling; the probe may be burned if the power is too high (see procedure below). A limitation is set to 20dB on nmr500 for this experiment. The recycle delay must be long enough (>1 sec) for the probe to cool in between scans.