An Introduction to NMR

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Made by Austin Clark ('18, MIT)
Created May 3, 2015, for ES/CMS.333 (MIT ESG)

Nuclear Magnetic Resonance spectroscopy (NMR for short) is a technique employed in the laboratory setting.

NMR involves the use of magnetic fields and energy to excite nuclei out of an equilibrium state; from the excited state, nuclei relax back to the equilibrium state. Data obtained from this relaxation provides information about the electron environments surrounding the nuclei. Since electron environments can describe bonding, data from the NMR spectrometer ultimately describe the bonding within a sample. Identifying the bonds within in a chemical species helps identify the species itself. Thus, NMR helps identify the compound(s) present in a chemical sample.
I intend for this video to help undergraduates in laboratories and in their studies.
Note: The type of NMR spectroscopy described in this video is the Pulsed-FFT spectroscopy--the most common application of NMR. An older but still used technique in NMR spectrometers is the Continuous wave (CW) spectroscopy. See the wikipedia page on NMR for more details:
Additional Note: The number of spin states available for a nucleus = 2I+1 (where I = the net-spin)

For nuclei with a net-spin greater than 1/2, more than 2 spin states exist. However, both hydrogen (1H) and carbon (13C) have net-spins of 1/2. Since hydrogen and carbon are the most abundant elements in organic compounds, 1H and 13C NMR spectrums are the most helpful and the most common NMR spectrums run. Know that this "Up" and "Down" spin-state (m=1/2, m=-1/2) situation is unique to 1/2 spin nuclei.

Helpful additional links:
NMR Spectroscopy
Principles of NMR
NMR
Larmor Precession

Special Thanks to:
Patricia D Christie
Jeffrey H Simpson
Ceri Riley
Tyler Moore, MD
Dave Custer, Graham Ramsay

Music Contributers:
"Red Sorrow" -- Audiomachine
"The King of the Highlands" -- Antti Martikainen

Image Contributers:
Menthol Spectrum NCI at Frederick