Nmr peak width

1. What is NMR line width?
2. What does a broad NMR peak mean?
3. What affects line width in NMR?
4. Why are oh peaks broad in NMR?

What is NMR line width?

1.4 Linewidth. The phenomenological linewidth is defined as the full-width at half-height (FWHH) of the resonance lineshape and is a primary factor affecting both resolution and signal-to-noise ratio of NMR spectra.

What does a broad NMR peak mean?

Broad peaks can represent inhomogeneities in the magnetic field which may have been caused by poor shimming, paramagnetic materials in the sample or particulate matter. Alternatively, peaks can broaden due to exchange processes on the NMR time scale.

What affects line width in NMR?

The main cause of the line width increase is fast T₂ relaxation caused by dipolar coupling and chemical shift anisotropy combined with slow molecular motion.

Why are oh peaks broad in NMR?

The ¹H-NMR resonances of phenol –OH groups display broad signals at room temperature due to intermolecular exchange of the –OH protons with protons of the protic solvents or with protons of the residual H₂O in aprotic solvents.