Characterization of High-Valent Oxo-Metalloporphyrins

Abstract

High-valent oxo metalloporphyrins have been known as reactive intermediates in the catalytic cycles of many heme enzymes and in the oxidation reactions mediated by synthetic metalloporphyrins. In this review, we survey studies of high-valent oxo metalloporphyrins in the past decade. In Sect. 2, electronic structures and magnetic properties of compound I and compound II species in various heme enzymes are discussed on the basis of recent studies of synthetic model complexes of the compound I and compound II. In Sect. 3, spectroscopic properties of oxo manganese porphyrin complexes and their application to biological systems are summarized. In the Sects. 4 and 5, synthesis and characterization of oxo chromium and oxo ruthenium porphyrin complexes are reviewed. In the last section, we have summarized the synthesis and characterization of Mo, Nb, Ti, and V oxo metalloporphyrins complexes.

Biomimetic Reactivity of Oxygen-Derived Manganese and Iron Porphyrinoid Complexes

“…Excellent reviews on the reactivity of iron-oxo porphyrin complexes can be found in the literature, including those from Fujii (2000, 21 2002 22 , 2016 23 ) Meunier et al (2004), 24 Groves (2006), 25 Newcomb (2006), 26 Nam (2007), 27 Costas (2011), 28 Ray and Meyer (2012), 29 and Rutkowska-Zbik (2014) 30 . Dedicated chapters in The Porphyrin Handbook (2000), 18,31-34 Handbook of Porphyrin Science, 35 and other compilations 36-38 can also be found.…”

Kinetic studies of reactions of iron(IV)-oxo porphyrin radical cations with organic reductants

“…The chemistry of porphyrin-metal-oxo [10], corrole-metal-oxo [7,[11][12][13][14][15], and corrolazine-metaloxo species [16,17] have received considerable attention. Iron(IV)-oxo porphyrin radical cation models of Compound I have been known for more than two decades [18], and they have been characterized by various spectroscopic methods, such as UV-vis, EPR, Mö ssbauer, EXAFS and Raman spectroscopies [19].…”

An Fe IV O complex of a tetradentate tripodal nonheme ligand

“…Such species have been trapped in the catalytic cycles of heme enzymes such as cytochrome P450 (2,3) and peroxidases (where these species are referred to as compounds I and II) (1). The generation and characterization of corresponding biomimetic oxo-iron(IV) porphyrin complexes have significantly enhanced our understanding of their structural, spectroscopic, and reactivity properties (4,5). A diiron(IV) intermediate called Q has been identified with Mössbauer spectroscopy in the catalytic cycle of the nonheme diiron enzyme methane monooxygenase (6)(7)(8); this intermediate has been proposed from extended x-ray absorption fine structure (EXAFS) evidence to have an Fe IV 2 ( -O) 2 core structure (9).…”