Air Oxidation of a Five-Coordinate Mn(III) Dimer to a High-Valent Oxomanganese(V) Complex

MacDonnell, Frederick M.; Fackler, Nathanael L. P.; Stern, Charlotte L.; O’Halloran, Thomas V.

doi:10.1021/ja00095a066

“…In order to prevent the dissipation of oxidizing power, electron transfer between the water-oxidizing manganese and its neighbours may be required to be slow on the time scale of the water oxidation step. The water oxidation site has been variously proposed to be an Collins et al 1990;MacDonnell et al 1994) and an adjacent octahedral Mn IV would again lead to high reorganization barriers. In all cases, the manganese with the oxo or oxyl radical bound to it would be expected to have a preference for the higher-oxidation state, leading to slow electron exchange.…”

Section: Electron Transfer Between Manganese Ions In the Oxygen-evolvmentioning

confidence: 99%

Water oxidation chemistry of photosystem II

Brudvig

¹

2007

Phil. Trans. R. Soc. B

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Photosystem II (PSII ) uses light energy to split water into protons, electrons and O 2 . In this reaction, nature has solved the difficult chemical problem of efficient four-electron oxidation of water to yield O 2 without significant amounts of reactive intermediate species such as superoxide, hydrogen peroxide and hydroxyl radicals. In order to use nature's solution for the design of artificial catalysts that split water, it is important to understand the mechanism of the reaction. The recently published X-ray crystal structures of cyanobacterial PSII complexes provide information on the structure of the Mn and Ca ions, the redox-active tyrosine called Y Z and the surrounding amino acids that comprise the O 2 -evolving complex (OEC). The emerging structure of the OEC provides constraints on the different hypothesized mechanisms for O 2 evolution. The water oxidation mechanism of PSII is discussed in the light of biophysical and computational studies, inorganic chemistry and X-ray crystallographic information.

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“…[25,28,[34][35][36][37][38] Indeed, these complexes possess the ability to form high-valent Mn-oxo species, [39,40] the sixth position being occupied by various ligands. [41,42] In particular, the use of pyridine as the sixth ligand has been proposed to assist the formation of Mn Voxo species from the [(salen)Mn III ] + complex, using tertbutyl hydroperoxide as the oxidant.…”

Section: Mnmentioning

confidence: 99%

Synthesis, Structure and Characterisation of a New Trinuclear Di‐μ‐phenolato‐μ‐carboxylato Mn^IIIMn^IIMn^III Complex with a Bulky Pentadentate Ligand: Chemical Access to Mononuclear Mn^IV–OH Entities

Hureau

¹

,

Anxolabéhère‐Mallart

²

,

Blondin

³

et al. 2005

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“…In the former cases, a high reorganization barrier is expected for electron transfer between the water-oxidizing Mn IV site and the JahnTeller distorted Mn III site. In the latter case, an octahedral Mn V water-oxidizing site would lead to a lower reorganization barrier due to a lower degree of Jahn-Teller distortion in Mn V as compared with Mn III , but electron exchange between a square pyramidal Mn V (a probable geometry for an Mn V ]O moiety; Collins & Gordon-Wylie 1989;Collins et al 1990;MacDonnell et al 1994) and an adjacent octahedral Mn IV would again lead to high reorganization barriers. In all cases, the manganese with the oxo or oxyl radical bound to it would be expected to have a preference for the higher-oxidation state, leading to slow electron exchange.…”

Section: Electron Transfer Between Manganese Ions In the Oxygen-evolvmentioning

confidence: 99%

Water oxidation chemistry of photosystem II

Vrettos

¹

,

Brudvig

²

2002

Phil. Trans. R. Soc. Lond. B

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Photosystem II (PSII ) uses light energy to split water into protons, electrons and O 2 . In this reaction, nature has solved the difficult chemical problem of efficient four-electron oxidation of water to yield O 2 without significant amounts of reactive intermediate species such as superoxide, hydrogen peroxide and hydroxyl radicals. In order to use nature's solution for the design of artificial catalysts that split water, it is important to understand the mechanism of the reaction. The recently published X-ray crystal structures of cyanobacterial PSII complexes provide information on the structure of the Mn and Ca ions, the redox-active tyrosine called Y Z and the surrounding amino acids that comprise the O 2 -evolving complex (OEC). The emerging structure of the OEC provides constraints on the different hypothesized mechanisms for O 2 evolution. The water oxidation mechanism of PSII is discussed in the light of biophysical and computational studies, inorganic chemistry and X-ray crystallographic information.

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Air Oxidation of a Five-Coordinate Mn(III) Dimer to a High-Valent Oxomanganese(V) Complex

Cited by 135 publications

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Water oxidation chemistry of photosystem II

Water oxidation chemistry of photosystem II

Synthesis, Structure and Characterisation of a New Trinuclear Di‐μ‐phenolato‐μ‐carboxylato Mn^IIIMn^IIMn^III Complex with a Bulky Pentadentate Ligand: Chemical Access to Mononuclear Mn^IV–OH Entities

Water oxidation chemistry of photosystem II

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Air Oxidation of a Five-Coordinate Mn(III) Dimer to a High-Valent Oxomanganese(V) Complex

Cited by 135 publications

References 0 publications

Water oxidation chemistry of photosystem II

Water oxidation chemistry of photosystem II

Synthesis, Structure and Characterisation of a New Trinuclear Di‐μ‐phenolato‐μ‐carboxylato MnIIIMnIIMnIII Complex with a Bulky Pentadentate Ligand: Chemical Access to Mononuclear MnIV–OH Entities

Water oxidation chemistry of photosystem II

Contact Info

Product

Resources

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Synthesis, Structure and Characterisation of a New Trinuclear Di‐μ‐phenolato‐μ‐carboxylato Mn^IIIMn^IIMn^III Complex with a Bulky Pentadentate Ligand: Chemical Access to Mononuclear Mn^IV–OH Entities