As you know the shielding and the deshielding process effect the position, appearance and disappearance of the protons. Also the nature of your molecule , solvent , hydrogen bonding( inter and intra) and temperature all these factors may effect proton behavior .

Which solvent are you using for your samples? Do you want to report the OH or NH signals? If you are using any 100% deuterated solvent and don't need to report those signals,  you can add a drop of D2O to your samples an that will make the exchangeable protons disappear  from your spectra  making your analysis easier. If you are using a mix H2O/D2O consider to change to 100% D2O.

 I am using DMSO-d6 as a solvent. I have already done D2O exchange for the samples and also by looking the spectrum, I can make out whether its a NH or OH proton (comes as a broad singlet). But, in a series of compounds (all are analogues of a drug), they are appearing anywhere and sometimes not all of them are appearing. So, I am not understanding whether to report these NH/OH protons or not. 

In this case i will prefer to not report these NH/OH protons, and in the materials and methods I'd mention that the NH/OH where exchanged with D2O. It's  preferable always to exchange these protons unless you need to look to them for some special reason. 

Thanks Roberto for your suggestion.

Thank you all for this valuable information.

You may want to check out my publications "On Hydrogen Bonding and OH chemical Shifts" Parts I and II, and "On NH NMR Chemical Shifts", Parts I - Part IV; they contain detailed explanations, many examples from the literature, as well as many references. Full texts are free on Research Gate. 

Without seeing your actual spectra and the proposed structures of your compounds, it is difficult to give you advice how to report the OH and or NH chemical shifts. However, my opinion is that all pertinent information should be disclosed in a publication of research results; that includes the presence or absence of resonances, as well as all experimental details (solvents, concentrations, temperature, etc.). OH and NH chemical shifts, peak shapes, etc., can often provide important information about molecular structure, hydrogen bonding, etc., and should not be simply ignored.

Good luck in your research! AF

I want to ask if NH can appear as doubled signal if there is CH is neighbour for it ?

Does D2O exchange occur when the NMR of the sample is done in DMSO-d6. For a simple organic compound, I have taken the 1H NMR in DMSO-d6 solvent. A compartively broad peak (not so broad) is observed at 6.39 ppm. When carried out the D2O exchange, the peak retained. From the concept, it should not be a -NH proton. But, is it sometime possible that a NH proton also not undergoes D2O exchange.

No It doesn't.

hi

add drop of TFA solvent into the sample if NH proton it will convert TFA salt.

2DNMR HETCOR N_H experiment

Is very good for distingusih between NH. and OH signals

Where the correlation between N and H

where observed

Protons on N or O typically have wide ranges of expected chemical shifts; the actual δ value depends on the solvent used, the concentration, temperature, etc. Because these protons are acidic and, therefore, exchangeable

they may be broad peaks and usually do not couple with neighboring protons (typically they are broad singlets). If a protic deuterated solvent is used (e.g., D2O or CD3OD), then the NH and OH protons will exchange with the deuterium and the peaks will shrink or disappear entirely, since D (2H) does not show up in the 1H NMR spectrum.

hi ,

if we take the proton NMR of Paracetamole compound in DMSO as the solvent the NH and OH peak will be formed. but when we use the D2O as the solvent for the same compound, those two peak will not be observed why?

can anyone explain why with reference?

Mr Kuntoji , as Mr Muala Said the deuterium proton will exchanged with proton therefore the two peaks will not be observed ..

thank you.

thank you Mr. Zafer sir for your valuable response.

To interpret -NH and -OH peaks in proton NMR and how to report them in a publication . First you have to carry out D2O exchange to know NH or OH protons. If NH is present one can see delta between 4.5 to 8.5 depending up on NH2 or =NH protons respectively. For OH alcoholic see delta 3 to 4 and for phenolic or enolic (broader signal)see delta 10 to 11.5 ppm.

You can compare the NMR spectrum of the compound with these functional groups in an aprotic solvent and a protic solvent like heavy water. The peaks that disappear are mainly the OH and NH peaks as a result of proton deuterium exchange. Also the OH and NH peaks usually appear broad and rarely split especially when the NMR was run on the sample at room temperature and the proton exchange between the OH and NH protons and that of the protic solvent appears very fast. Thus looking at the splitting pattern and the disappearance of peaks in different solvents, you can tell the differences and pinpoint out the OH and NH peaks.

The main challenge is differentiating between the OH Peaks and that of the NH peaks since they mostly overlap and appear at various deltas depending on the functional group whether amides, arenes, alcohols, phenols, aryl amides and co so with the two the main difference is the fact that the OH Peaks are mostly broader since the exchange of protons with the solvent protons is relatively faster than that of the NH protons so you can differentiate between the two with I think D2O or you can add a drop of TFA to the sample. The peak that disappear in the PMR spectrum of the resulting product is the NH peak as it interacts with TFA to form salt I think. You can of course check and review other references to get more insights.

can a vicinal CH peak split a NH peak (and vice versa) in 1H NMR

Can anyone suggest me how to distinguish between two -NH proton in NMR . I mean my ligand structure consists if two -NH proton. From NMR it was observed one -NH peak resonated at 11.27ppm and another at 10.59ppm. Both the NH protons lie side by side and both of them are attached to carbonyl group on either side. Now I have to ascertain which NH proton posses 11.27 ppm value and 10.59 ppm. Structure is given below. Should I go for D2O exchange NMR.plz help.

O=C-NH-NH-C=O

Dear. Lubana

I think your compound contains only one chemical environment for NH proton, this is attributed to the presence of one plane of symmetry. So, the NH will appear in one signal, not two. you can confirm your result using the D2O experiments.

Best regards.