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== '''[[ | == '''[[NMR spectroscopy]]''' == | ||
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'''NMR spectroscopy''' (MR spectroscopy, NMR or Nuclear Magnetic Resonance Spectroscopy) measures the energy differences between the spin states of nuclei in the presence of a magnetic field by using radio frequency electromagnetic radiation.<ref> I. I. Rabi.(1937) Phys. Rev., 51 652</ref><ref>N. Bloembergen, E. Purcell and R.V.Pound. (1948). Phys. Rev. 73, 679.</ref> <ref>F. Bloch, W. Hansen, and M.E. Packard, (1946) Phys. Rev. 69, 127.</ref> The energy differences between the spin states of the nuclei depend upon the nature of the atom and are influenced by its environment. However, NMR spectroscopy is not limited to measurement of the energy differences between the spin states. NMR signals are also influenced by the motion of the nucleus and the rotational motion of the molecule within which the observed nucleus resides. Therefore, NMR spectroscopy provides static (structure and composition) as well as dynamic information regarding the system of interest, e.g., [[protein]]s, [[DNA]] and other natural products. | |||
''[[ | Pulses of radio-frequency electromagnetic radiation can be used to perturb the nuclear spin systems in a variety of ways; the time dependent response of the system of interest can be recorded and analyzed: | ||
* to correlate different spectral properties of nuclei and/or | |||
* to extract information regarding interactions between nuclear spins within the same molecule and/or | |||
* to obtain information regarding intermolecular interactions. | |||
The amplitude, frequency, phase and duration of pulses of radio-frequency electromagnetic radiation, as well as static and dynamic position dependent magnetic fields, can be varied in many combinations giving rise to a wide variety of NMR spectroscopic experiments. | |||
NMR spectroscopic techniques are used extensively for structural elucidation of natural products and for quantitative analysis of components of complex mixtures such as body fluids. However, its applications are not limited to these systems; and | |||
NMR spectroscopy has been used for the study of matter in disordered, ordered and partially ordered systems such as gases, liquids, [[quantum fluids]] | |||
<ref>D.D.Osheroff, W.J.Gully, R.C.Richardson and D.M.Lee, Phys. Rev. Lett. (1972) 29, 920 </ref> <ref>http://nobelprize.org/nobel_prizes/physics/laureates/1996/lee-lecture.pdf </ref>, | |||
superconductors, solutions, amorphous solids, crystalline solids, [[liquid crystals]], membranes and living organisms. NMR spectroscopic methods have also found use in [[quantum computing]]. | |||
''[[NMR spectroscopy|.... (read more)]]'' | |||
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Revision as of 09:39, 16 August 2012
NMR spectroscopy
NMR spectroscopy (MR spectroscopy, NMR or Nuclear Magnetic Resonance Spectroscopy) measures the energy differences between the spin states of nuclei in the presence of a magnetic field by using radio frequency electromagnetic radiation.[1][2] [3] The energy differences between the spin states of the nuclei depend upon the nature of the atom and are influenced by its environment. However, NMR spectroscopy is not limited to measurement of the energy differences between the spin states. NMR signals are also influenced by the motion of the nucleus and the rotational motion of the molecule within which the observed nucleus resides. Therefore, NMR spectroscopy provides static (structure and composition) as well as dynamic information regarding the system of interest, e.g., proteins, DNA and other natural products.
Pulses of radio-frequency electromagnetic radiation can be used to perturb the nuclear spin systems in a variety of ways; the time dependent response of the system of interest can be recorded and analyzed:
- to correlate different spectral properties of nuclei and/or
- to extract information regarding interactions between nuclear spins within the same molecule and/or
- to obtain information regarding intermolecular interactions.
The amplitude, frequency, phase and duration of pulses of radio-frequency electromagnetic radiation, as well as static and dynamic position dependent magnetic fields, can be varied in many combinations giving rise to a wide variety of NMR spectroscopic experiments.
NMR spectroscopic techniques are used extensively for structural elucidation of natural products and for quantitative analysis of components of complex mixtures such as body fluids. However, its applications are not limited to these systems; and NMR spectroscopy has been used for the study of matter in disordered, ordered and partially ordered systems such as gases, liquids, quantum fluids [4] [5], superconductors, solutions, amorphous solids, crystalline solids, liquid crystals, membranes and living organisms. NMR spectroscopic methods have also found use in quantum computing.
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