Nuclear magnetic resonance bohr magneton

MCD, magnetic circular dichroism EPR, electron paramagnetic resonance NMR, nuclear magnetic resonance DBM, Debye-Bohr magneton ADP, adenosine diphosphate ARN, adenosine-5 -nicotinate FAD, flavin-adenine dinucleotide... 

The authors do not mention the values of the nuclear g-factors, but we may take them to be gF = +2.628 87 and gN = +0.403 76 nuclear Bohr magnetons. Consequently it is now a simple matter to calculate the energies of the 30 levels for a range of magnetic fields between 9400 and 10 600 G the magnetic resonance transitions are those which obey the selection rules AM/ = 1, AMn = AMp = 0 and their frequencies may also be calculated. 

In a static magnetic field Bq (of magnitude = Bol)> isolated nucleus n resonates at the Larmor frequency v determined by its nuclear g value g and the nuclear Bohr magneton /3,v- = g N o, where h is Planck s... 

Comparison of equation (9.21) with equations (9.9) and (9.6) reveals the resemblance of nuclear and electron resonance methods. In equation (9.21), P is the so-called Bohr magneton, and the electron g value is a porportionality constant which is dependent upon the magnetic species and its environment. Only unpaired electrons give rise to ESR spectra, and this is why, except in the study of lipid autoxidation, lipids can only be studied through the use of spin labels, which are stable, usually nitroxide, radicals (Fig. 9.26). 

Electron spin resonance spectroscopy is formally similar to NMR if one considers an unpaired electron as taking the role of a spin -1/2 nucleus in an NMR experiment. However, because of the much greater size of the electron magneton (the Bohr magneton) versus the nuclear magneton, much weaker external fields are employed in order to observe transitions with radiofrequency radiation. As a result, coupling interactions between the electron and magnetic nuclei may require a treatment beyond that of first-order perturbation theory. 

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