Diamond core structure, methane monooxygenase

Shu LJ, Nesheim JC, Kauffmann K, Miinck E, Lipscomb JD, Que L. An Fe2IV02 diamond core structure for the key intermediate Q of methane monooxygenase. Science. 1997 275 515-8. 

If these calculations prove correct, the high reactivity of the "activated" O2 (i.e. H-abstraction from unactivated C-H bonds) may be associated with Mdging rather than terminal oxo-ligands. We note that the most recent proposal for the reactive interm ate of methane monooxygenase features a "Fe2(li-0)2 diamond core structure" much like the one shown in Figure 2. [19]... 

Hsu, H., Dong, Y., Shu, L.,Young, J., V. G., and Que, J., L., 1999, Crystal structure of a synthetic high-valent complex with an Fc2(p-0)2 diamond core. Implications for the core structures of methane monooxygenase intermediate Q and ribonucleotide reductase intermediate X, J. Am. Chem. Soc. 121 5230n5237. 

Dioxygen diiron complexes have been synthesized by mimicking the probable intermediate structures in methane monooxygenase oxygenations. Examples are summarized in the recent review. One is the Fc2(i7-0)2 diamond core type and the other is the Fe2(tJ-02) peroxo type. Recently, an unusual Fe"-X-Fe (tl -02) species has been suggested in the reaction of O2 with carboxylate-bridged diiron(II,II) paddlewheel complexes, but its role in the oxygenation has not been clarified. ... 

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