NMR(Nuclear Magnetic Resonance) is a technique to study and determine the structure of molecules(the bond structure, bond angle, orientation etc). MRI(Magnetic Resonance Imaging) is scaled up version of NMR machine. NMR can be classified as liquid NMR and solid NMR depending upon the sample used for the NMR spectroscopy.

NMR uses one large homogenous magnetic field and RF magnetic field to perturb the orientation of the molecules nuclear spin and sense the realignment of the spin to its original position. Overall NMR studies the magnetic properties of molecules using magnets and electromagnetic fields.

The precise structural information of the sample under study is the aim of the NMR spectroscopy. NMR spectroscope is also less constraint measurement technique because 1mg of pure material is adequate for the study as compared to other techniques like mass spectroscopy which requires 1ug(microgram). NMR can give good information about complex molecule because it gives signal intensity depending upon the molecule makeup.

NMR instrument are expensive(approx. $100,000 to $6 million).  They are more expensive then its competitor instruments light spectroscopy, mass spectroscopy but also reveals more information about the structure of the molecules. On the determination of structure only X-ray crystallography can give comparable result.

The signal obtained from NMR are used using CAD to obtain 3D view of the molecule.


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