Nuclear Magnetic Resonance (N.M.R.) Spectroscopy

The basis of N.M.R.

The N.M.R. Machine

How it works:

  1. The magnetic field is held constant while a band of frequencies is applied as a pulse to the sample.
  2. The radio-frequency results in the nuclei energy level increasing; immediately after this increase, there will be a greater than normal amount of protons at the higher energy level. Some of these emit radiation as they move down to the lower energy level.
  3. This radiation is measured by the detector and sent to the recorder.
  4. The radiation is weak and the process is over very quickly, so it is repeated many times to ensure that a valid result is returned.
  5. A graph of absorption against frequency (referred to as chemical shift) is produced.

Interpreting the Spectra

High Resolution N.M.R

Useful books for revision

Revise A2 Chemistry for Salters (OCR A Level Chemistry B)
Salters (OCR) Revise A2 Chemistry