Magnetic and spectroscopic characterization of an iron porphyrin peroxide complex.  Peroxoferrioctaethylporphyrin(1-)

Burstyn, Judith N.; Roe, James A.; Miksztal, Andrew R.; Shaevitz, Ben A.; Lang, Georgina; Valentine, Joan Selverstone

doi:10.1021/ja00213a009

Cited by 117 publications

(84 citation statements)

References 3 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The g 2 -peroxo form has been identi®ed with heme systems [61,62], EDTA 4) [39±41], and polydentate aminopyridine ligands [8,11,42]. The g 1 -peroxo may exist in some heme systems but it is not yet proven spectroscopically.…”

Section: Resultsmentioning

confidence: 99%

Characterization and Properties of Non-Heme Iron Peroxo Complexes

Girerd

Banse

Simaan

2000

Structure and Bonding

154

168

View full text Add to dashboard Cite

Section: Resultsmentioning

confidence: 99%

Characterization and Properties of Non-Heme Iron Peroxo Complexes

Girerd

Banse

Simaan

2000

Structure and Bonding

154

168

View full text Add to dashboard Cite

“…We have simulated the spectrum of Table 2 shows that the parameters extracted from the analysis of data for 1b resemble those of other η 2 -peroxoiron-(III) complexes. 31,40,57 The δ values (range 0.61-0.67 mm/ s) are somewhat higher than is typical for a high-spin iron(III) center and appear to be a signature for side-on peroxo coordination. Such larger δ values are also associated with some (µ-1,2-peroxo)diiron(III) complexes, 61,62 but other (µ-1,2-peroxo)diiron(III) complexes have isomer shifts in the normal range for high-spin iron(III) centers.…”

Section: Peroxo Deriwatiwes Of Non-heme Iron Complexesmentioning

confidence: 94%

“…38 The only other established (η 2 -peroxo)iron complexes prior to these studies are those of Fe III (EDTA) 39 and Fe III (porphyrin). 40 The existence of an acid-base equilibrium affording low-spin Fe III -η 1 -OOH and high-spin Fe III -η 2 -O 2 species in one ligand system provides a unique opportunity to investigate how the change in peroxo binding mode affects the spectroscopic properties of the metal center.…”

Section: -Carboxylic Acid N-[2-(4′-imidazolyl)ethyl]amide;mentioning

confidence: 99%

End-On and Side-On Peroxo Derivatives of Non-Heme Iron Complexes with Pentadentate Ligands: Models for Putative Intermediates in Biological Iron/Dioxygen Chemistry

et al. 2003

View full text Add to dashboard Cite

Mononuclear iron(III) species with end-on and side-on peroxide have been proposed or identified in the catalytic cycles of the antitumor drug bleomycin and a variety of enzymes, such as cytochrome P450 and Rieske dioxygenases. Only recently have biomimetic analogues of such reactive species been generated and characterized at low temperatures. We report the synthesis and characterization of a series of iron(II) complexes with pentadentate N5 ligands that react with H 2 O 2 to generate transient low-spin Fe III −OOH intermediates. These intermediates have low-spin iron(III) centers exhibiting hydroperoxo-to-iron(III) charge-transfer bands in the 500−600-nm region. Their resonance Raman frequencies, ν O-O , near 800 cm -1 are significantly lower than those observed for high-spin counterparts. The hydroperoxo-to-iron(III) charge-transfer transition blue-shifts and the ν O-O of the Fe−OOH unit decreases as the N5 ligand becomes more electron donating. Thus, increasing electron density at the low-spin Mononuclear iron(III) peroxide species are implicated as intermediates in the mechanisms of oxygen activating biomolecules such as cytochrome P450, 1 heme oxygenase, 2 the antitumor drug bleomycin, 3 and Rieske dioxygenases, 4,5 as well as superoxide reductases from anaerobic bacteria. [6][7][8][9] Experimental evidence for some of these intermediates has

show abstract

“…Early studies performed on compounds 14a and 15 led researchers to formulate these species as side-on bound (η 2 -peroxo)Fe(III) species on the basis of spectroscopic evidence from EPR, Mössbauer, and magnetic measurements, which confirmed the high-spin Fe(III) state of the iron center [39,40]. Further characterization of the O-O and Fe-O bonding by IR, rR, and EXAFS spectroscopy supported a symmetrically bound peroxo ligand [39,41].…”

Section: Fe(iii)-superoxo Intermediatesmentioning

confidence: 99%

Transition Metal Complexes and the Activation of Dioxygen

Yee

Tolman

2014

Metal Ions in Life Sciences

View full text Add to dashboard Cite

In order to address how diverse metalloprotein active sites, in particular those containing iron and copper, guide O₂binding and activation processes to perform diverse functions, studies of synthetic models of the active sites have been performed. These studies have led to deep, fundamental chemical insights into how O₂coordinates to mono- and multinuclear Fe and Cu centers and is reduced to superoxo, peroxo, hydroperoxo, and, after O-O bond scission, oxo species relevant to proposed intermediates in catalysis. Recent advances in understanding the various factors that influence the course of O₂activation by Fe and Cu complexes are surveyed, with an emphasis on evaluating the structure, bonding, and reactivity of intermediates involved. The discussion is guided by an overarching mechanistic paradigm, with differences in detail due to the involvement of disparate metal ions, nuclearities, geometries, and supporting ligands providing a rich tapestry of reaction pathways by which O₂is activated at Fe and Cu sites.

show abstract

Magnetic and spectroscopic characterization of an iron porphyrin peroxide complex. Peroxoferrioctaethylporphyrin(1-)

Cited by 117 publications

References 3 publications

Characterization and Properties of Non-Heme Iron Peroxo Complexes

Characterization and Properties of Non-Heme Iron Peroxo Complexes

End-On and Side-On Peroxo Derivatives of Non-Heme Iron Complexes with Pentadentate Ligands: Models for Putative Intermediates in Biological Iron/Dioxygen Chemistry

Transition Metal Complexes and the Activation of Dioxygen

Contact Info

Product

Resources

About