Nuclear Magnetic Resonance Spectroscopy:

Chemical Shift:

1) NMR spectrum is a plot of the ratio of the frequency applied against absorption.

2) A signal in the spectrum is referred to as a resonance.

3) The frequency of a signal is known as its chemical shift.

The chemical shift is defined as

The shielding of the nucleus allows for chemically inequivalent environments to be determined by Fourier Transforming the NMR signal, which results in a spectrum.

• In general, the spectrum consists of a set of peaks in which each peak corresponds to a distinct chemical environment.

• The area underneath the peak is directly proportional to the number of nuclei in that chemical environment.

• The x-axis of an NMR spectrum is given in parts per million (ppm).