Integer spin EPR

Surerus, K. K. Hendrich, M. P. Christie, P. D. Rottgardt, D. Orme-Johnson, W. H. Miinck, E. Mossbauer and integer-spin EPR of the oxidized P-clusters of nitrogenase POX is a non-Kramers system with a nearly degenerate ground doublet. J. Am. Chem. Soc. 1992, 114(22), 8579-8590. 

The diferrous state can have an integer spin EPR signal with a g-value in the range 18 to 12. Such signals are in general best observed... 

Both complexes exhibit a low field EPR signal at g = 16, presumably derived from a coupled diferrous system (88, 126). These complexes thus serve as models for deoxyHrNj and MMOred- What structural and electronic factors determine the appearance of an integer spin EPR signal from diferrous complexes is not understood at present, but the availability of such models provides opportunities to explore the effects of the coordination chemistry of the diferrous state on the properties of this signal. 

Hendrich MP, Milnck E, Fox BG, Lipscomb JD. 1990. Integer-spin EPR studies of the fully reduced methane monooxygenase hydroxylase component. J Am Chem Soc 112 5861-5865. 

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