Nitrite complexes oxygen atom transfer

Other metal complexes that will undergo oxygen-atom transfer from a coordinated nitrite are M(N02)2(C0)2(PPh3)2 (Af = Ru, Os), which oxidizes Co(Ar,AT-Bisalicylidene-o-phenylenediamino)pyN02, which... 

Recently, a MnTPyP species with four [Ru (bpy)2(OH2)] complexes coordinated to the pyridyl-substituents were synthesized and characterized. The oxidation of the peripheral aqua-complexes led to formation of [O = Ru" (bpy)2], a known oxygen-atom transfer catalyst. The films of this peripherally metal-lated porphyrin are too soluble, but can be stabilized by anion-exchange with [Fe(CN)6] or M-TPPS. The oxidation of nitrite occurred at 1.0 V and was catalyzed by that high-valent species. 

In summary, there is still much to understand about the nitrite reduction reaction. The crystal structures have shown how nitrite can bind to the di heme iron and protons can be provided to one of its oxygen atoms from two histidine residues. However, as yet no rapid reaction study has detected the release of product nitric oxide rather than the formation of the inhibitory dead-end ferrous di heme-NO complex. It is also not clear why the rate of interheme electron transfer is so slow over 11 A when nitrite or nitric oxide is the ligand to the d heme. 

In contrast to nitrosyls, the absence of a transferable oxygen atom in N2R ligands allows the preparation of stable diazenido complexes of oxophilic, early transition metals see for example Cp2TiCl(N2Ph). Furthermore, there are as yet no diazotate (RN=NO-) forming reactions anolo-gous to the nitrite forming reactions in nitrosyl chemistry (see equations 112 and 113). 

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