19496-63-0Relevant articles and documents
Heme/Hydrogen peroxide reactivity: Formation of paramagnetic iron oxophlorin isomers treatment of iron porphyrins with hydrogen peroxide
Kalish,Latos-Grazynski,Balch
, p. 12478 - 12486 (2000)
Treatment of iron(II) porphyrins, (py)2FeII(OEP), (py)2FeII(EtioP), (py)2FeII(DeuteroP), (pY)2-FeII(MesoP), and (py)2FeII(ProtoP), where OEP are the dianions of octaethylporphyrin, etio-1 porphyrin, deuteroporphyrin-IX dimethyl ester, mesoporphyrin-IX dimethyl ester, and protoporphyrin-IX dimethyl ester, with hydrogen peroxide in pyridine-d5 at -30°C in the strict absence of dioxygen is shown to result in clean oxygenation of the heme and the formation of oxophlorin complexes, (py)2Fe(OEPO), (py)2Fe(EtioPO), (py)2Fe-(DeuteroPO), (py)2Fe(MesoPO), and (py)2Fe(ProtoPO). Reactions have been monitored by 1H NMR spectroscopy. The product oxophlorin complexes are stable as long as the samples are protected from exposure to dioxygen. The hyperfine shift patterns and the relative intensities of the individual resonances have been analyzed in terms of a model in which the location of the meso oxygen substituent dominates the pattern of spin density distribution. The resulting 1H NMR spectra obtained from oxidation of the unsymmetrically substituted hemes, (py)2FeII(DeuteroP), (py)2FeII(MesoP), and (py)2FeII(ProtoP), with hydrogen peroxide have been analyzed. These spectra show that the four isomeric oxophlorin products are formed in a nonrandom fashion. Solvent effects can produce a significant alteration in the regiospecificity of heme oxygenation.
Electronic origin of variable denitrosylation kinetics from isostructural {FeNO}7 complexes: X-ray crystal structure of [Fe(oetap)(NO)]
Bohle, D. Scott,Debrunner, Peter,Fitzgerald, Jeffrey P.,Hansert, Bernhard,Hung, Chen-Hsiung,Thomson, Andrew J.
, p. 91 - 92 (2007/10/03)
In contrast to the nitrosyl derivative of iron(II) octaethylporphyrin [Fe(oep)(NO)], the isostructural octaethyltetraazaporphyrin complex [Fe(oetap)(NO)] exhibits fast ligand-promoted nitric oxide dissociation in the presence of pyridine and N-methylimidazole.
SYNTHESES AND MAGNETIC PROPERTIES OF ARYLIRON(III) COMPLEXES OF OCTAETHYLPORPHYRINS
Ogoshi, Hisanobu,Sugimoto, Hiroshi,Yoshida, Zen-Ichi,Kabayashi, Hanako,Sakai, Hiroshi,Maeda, Yutaka
, p. 185 - 196 (2007/10/02)
Aryliron(III) octaethylporphyrins, OEP-FeIII(4-XC6H4) were obtained from octaethylporphyrinatoiron(III) perchlorate, OEP-FeIII(ClO4) and arylmagnesium bromides.In order to confirm the ESR parameters, the
Iron(II, III)-Chlorin and Isobacteriochlorin Complexes. Models of the Heme Prosthetic Groups in Nitrite and Sulfite Reductases: Means of Formation and Spectroscopoic and Redox Properties
Stolzenberg, Alan M.,Strauss, Steven H.,Holm, R. H.
, p. 4763 - 4778 (2007/10/02)
Extensive series of iron(II, III)-hydroporphyrin complexes of the types Fe(P)L, 0,+, 2O, and Fe(P), with P = octaethylchlorin (OEC) and octaethylisobacteriochlorin (OEiBC) and L, L' = neutral or uninegative axial ligands, have been synthesized and isolated or generated in solution.Means of synthesis and reactivity properties of OEC and OEiBC complexes parallel those of octaethylporphyrin (OEP) complexes.This behavior, together with a detailed body of physicochemical properties (absorption, MCD, 1H NMR, EPR, and infrared spectra and voltammetry), serves to identity all new complexes.Certain of the OEiBC species are pertinent as possible analogues of the siroheme prosthetic group of nitrite and sulfite reductases.Physicochemical properties of OEP, OEC, and OEiBC complexes at parity of axial ligation are compared in an attempt to identify any intrinsic features of isobacteriochlorin species that might render them particularly suitable for mediation of multielectron reductions of substrates as executed by siroheme enzymes.Properties such as Fe(III)/Fe(II) potentials and νCO of Fe(P)L(CO) and Fe(P)(CO)1,2 were found to be nearly invariant to P, indicating little cis effect of these macrocycles, which are in different reduction levels.That property most dependent on macrocycle structure was found to be the potential for ring-based oxidation which increases in the order OEiBC OEC OEP.Comparative properties are discussed in some detail and are related to available information on sirohemes, including the question of axial ligation in the native enzyme.This research affords the first comprehensive examination of the preparation and chemical, spectroscopic, and redox properties of iron(II, III)-hydroporphyrin complexes.
