No abstract

No abstract

formed, the first one, a hemoprotein Fe(II)-CH3N=NH complex being further oxidized by 1 equiv of Fe(CN)6K3 (or by 02) to give another complex, B, of unknown structure. When R = C6H5, the Fe(II)-C6H5N=NH complex has never been observed, the only entity formed being a complex spectrally similar to B.27 This paper describes the first isolation of a porphyriniron(II)-alkyldiazene complex22 and points to the great instability of Fe(II)-C6H5N=NH complexes, thus strongly supporting the existence of Mb-(or Hb-) Fe(II)-CH3N=NH complexes10 and explaining the failure to observe Mb-Fe(II)-C6H5N=NH complexes.93•10,23The diazene ligands are isoelectronic with their oxygen-containing analogues, nitrosoalkanes15 and 02, and it is noteworthy that, as their diazene analogues, nitrosoarene-iron porphyrin complexes are considerably less stable than nitrosoalkane-iron complexes.150This paper also reports for the first time the formation of -Fe-(III)-R complexes upon reaction of RNHNH2 or RN=NH with iron porphyrins, indicating a possible HbFem-R (R = CH3 or C6H5) structure for complexes B.27 However, one cannot exclude presently the previously proposed9 HbFem-N=NR structure for these complexes. In that respect, it is noteworthy that hydrazines RNHNH2 react with Co and Fe chelates to give Co(III)-R and Fe(III)-R complexes,24 whereas C6H5NHNH2 reacts with molybdenum porphyrins to give Finally, very recent preliminary results are in favor of the formation of similar iron complexes during the cytochrome P-450 dependent oxidation of CH3NHNH226 and C6H5NHNH2.3•26 (21) (a) Reed, C.

No abstract

No abstract