Electron nuclear resonance ENDOR spectroscopy

To resolve hf and nuclear quadrupole interactions which are not accessible in the EPR spectra, George Feher introduced in 1956 a double resonance technique, in which the spin system is simultaneously irradiated by a microwave (MW) and a radio frequency (rf) field3. This electron nuclear double resonance (ENDOR) spectroscopy has widely been applied in physics, chemistry and biology during the last 25 years. Several monographs2,4 and review articles7 11 dealing with experimental and theoretical aspects of ENDOR have been published. 

Electron-nuclear double resonance (ENDOR) spectroscopy A magnetic resonance spectroscopic technique for the determination of hyperfine interactions between electrons and nuclear spins. There are two principal techniques. In continuous-wave ENDOR the intensity of an electron paramagnetic resonance signal, partially saturated with microwave power, is measured as radio frequency is applied. In pulsed ENDOR the radio frequency is applied as pulses and the EPR signal is detected as a spin-echo. In each case an enhancement of the EPR signal is observed when the radiofrequency is in resonance with the coupled nuclei. 

Magnetic resonance spectroscopy Nuclear magnetic resonance Electron paramagnetic resonance ENDOR... 

Electron-Nuclear Double Resonance (ENDOR) Spectroscopy. This observes a spin resonance transition after a nuclear resonance transition has been saturated by a radio-frequency pulse (Fig. 11.65) so as to invert the relative populations of the y.ey. > and y,./) .y> spin states this forces the populations of the aeaN> and fSey > states to be different and thus offers the opportunity to measure hyperfine splittings much more carefully, with better resolution than in standard EPR. 

Rigby, S.E.J., Evans, M.C.W., and Heathcote, P. (2000) Electron nuclear double resonance (ENDOR) spectroscopy of radicals in photosystem I and related type 1 photosynthetic reaction centers, Biochim. Biophys. Acta 1507 247-259. 

Electron Paramagnetic Resonance (EPR) Spectroscopy, Electron Spin Echo Envelope Modulation (ESEEM) Spectroscopy Electron-Nuclear Double Resonance (ENDOR) Spectroscopy Nuclear Magnetic Resonance (NMR) Spectroscopy of Inorganic/Organometallic Molecules. 

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