Zero-field splitting electron paramagnetic resonance

It is important to realize that no one method of spectroscopy is clairvoyant. Electron paramagnetic resonance spectroscopy cannot sense low-spin Fe(II) as this state is diamagnetic, nor reliably the high-spin Fe(II) state because of rapid spin-lattice relaxation, large zero-field splittings or both Mossbauer spectroscopy cannot distinguish Fe(III) spin states... 

ENDOR = electron nuclear double resonance EPR = electron-paramagnetic resonance ESR = electron-spin resonance NMR = nuclear magnetic resonance MA = modulation amplitude SOFT = second-order perturbation theory s-o = spin-orbit zfs = zero-field splitting (for S > 1 /2) D = uniaxial zfs E = rhombic zfs g = g-factor with principal components gy, and g ge = free electron g-factor a = hyperfrne splitting constant A = hyperftne coupling constant for a given nucleus N (nuclear spin 7>0). 

We have used two spectroscopic methods to investigate the triplet state of localized diradicals. On the one hand, matrix electron paramagnetic resonance (EPR) spectroscopy was employed, which affords the zero-field splitting (zfs) parameters D and E and gives valuable information on the electronic structure [5-7]. On the other hand, time-resolved transient... 

DPPH = 2,2-diphenyl-l-picrylhydrazyl ENDOR= electron-nuclear double resonance EPR = electron paramagnetic resonance ESE = electron spin echoes ESEEM = electron spin echo envelope modulation FFT = fast fourier transformations FWHM = full width at half maximum HYSCORE = hyperline sublevel correlation nqi = nuclear quadrupole interaction TauD = taurine/aKG dioxygenase TWTA = traveling wave tube amplifier ZFS = zero field splitting. 

Keywords Electron paramagnetic resonance Electron spin resonance Molecular nanomagnet Quantum coherence Single-molecule magnet Zero-field splitting... 

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