INQUIMAE   12526
INSTITUTO DE QUIMICA, FISICA DE LOS MATERIALES, MEDIOAMBIENTE Y ENERGIA
Unidad Ejecutora - UE
artículos
Título:
Successful stabilization of the elusive species {FeNO}8 in a heme model
Autor/es:
PELLEGRINO, J.; BARI, S. E.; BIKIEL, D. E.; DOCTOROVICH, F.
Revista:
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
Editorial:
AMER CHEMICAL SOC
Referencias:
Año: 2010 vol. 132 p. 989 - 989
ISSN:
0002-7863
Resumen:
Nitroxyl (HNO/NO-) heme-adducts have been postulated as intermediates in a variety of catalytic processes carried out by different metalloenzymes. Hence, there is growing interest in obtaining and characterizing heme model nitroxyl complexes. The one-electron chemical reduction of the {FeNO}7 nitrosyl derivative of FeIII(TFPPBr8)Cl, FeII(TFPPBr8)NO (1) (TFPPBr8 ) 2,3,7,8,12,13,17,18-octabromo-5,10,15,20-[Tetrakis-(pentafluorophenyl)]porphyrin) with cobaltocene yields the significantly stable {FeNO}8 complex, [Co(C5H5)2]+[Fe(TFPPBr8)NO]- (2). Complex 2 was isolated and characterized by UV-vis, FTIR, 1H and 15N NMR spectroscopies. In addition, DFT calculations were performed to get more insight into the structure of 2. According to the spectroscopic and DFT results, we can state unequivocally that the surprisingly stable complex 2 is the elusive {FeNO}8 species. Both experimental and computational data allow to assign the electronic structure of 2 as intermediate between FeIINO- and FeINO, which is contrasted with the predominant FeIINO- character of known nonheme {FeNO}8 complexes. The enhanced stability achieved for a heme model {FeNO}8 is expected to allow further studies related to the reactivity of this elusive species.