Electron paramagnetic resonance principles

B. Gallez, C. Baudelet, B.F. Jordan, Assessment of tumor oxygenation by electron paramagnetic resonance Principles and applications, NMR Biomed. 17 (2004) 240-262. 

Schweiger, A., Jeschke, G. Principles of Pulse Electron Paramagnetic Resonance. Oxford University Press, Oxford (2001)... 

Pake, G.E. and Estle, T.L. 1973. The Physical Principles of Electron Paramagnetic Resonance. Reading, MA W.A. Benjamin Inc. 

Electron paramagnetic resonance (EPR) and NMR spectroscopy are quite similar in their basic principles and in experimental techniques. They detect different phenomena and thus yield different information. The major use of EPR spectroscopy is in the detection of free radicals which are uniquely characterised by their magnetic moment that arises from the presence of an unpaired electron. Measurement of a magnetic property of a material containing free radicals, like its magnetic susceptibility, provides the concentration of free radicals, but it lacks sensitivity and cannot reveal the structure of the radicals. Electron paramagnetic resonance spectroscopy is essentially free from these defects. 

I. B. Goldberg, T. M. McKinney, Principles and techniques of electrochemical-electron paramagnetic resonance experiments in Laboratory Techniques in Electroanalytical Chemistry (Eds. P. T. Kissinger, W. R. Heineman),... 

We can deduce the meaning of the word spectroelectrochemistry by dissecting it piece by piece. Spectroelectrochemistry follows an electrochemical process by the use of electromagnetic radiation (hence spectra- ). In principle, any form of spectroscopy can be used to follow the progress of an electrode reaction, but in practice we tend to concentrate on two, namely UV—visible ( UV—vis ) spectroscopy and a form of microwave spectroscopy known as electron paramagnetic resonance (EPR), as described below. 

Principles and Techniques of Electrochemical-Electron Paramagnetic Resonance Experiments - 901... 

This chapter provides a review of the principles of electron paramagnetic resonance (EPR) as they apply to electrochemical studies. EPR is a spectroscopic... 

Electron paramagnetic resonance (EPR) is also referred to as electron spin resonance (ESR). In many respects, it is similar to NMR and the corresponding principles, discussed in the previous section, apply. The critical difference is that an unpaired electron spin is detected in this method instead of a nuclear spin. The method applies only to paramagnetic systems. The electron spin is more readily detected than is a nuclear spin and magnets on EPR instruments are correspondingly smaller and less expensive. 

Lippard, S. J., and Berg, J. M. (1994). Electron paramagnetic resonance (EPR) spectroscopy. In Principles of Bioinorganic Chemistry, (pp. 84-88). University Science Books, California. 

N. M. Atherton Principles of Electron Spin Resonance, Ellis Horwood/Prentice Hall, Hemel Hempstad, 1993. [185] M. C. R. Symons Application of ESR Spectroscopy to the Study of Solvation, Pure Appl. Chem. 49, 13 (1977). [186] (a) L. R. Dalton, A. Bain, and C. K. Westbrook Recent Advances in Electron Paramagnetic Resonance, Annu. Rev. Phys. Chem. 41, 389 (1990). (b) J. H. Freed New Techniques in ESR, Annu. Rev. Phys. Chem. 57, 655 (2000). [187] G. R. Luck-... 

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