Functional models for the oxygen-evolving complex of photosystem II

Cady, Clyde W.; Crabtree, Robert H.; Brudvig, Gary W.

doi:10.1016/j.ccr.2007.06.002

Cited by 384 publications

(264 citation statements)

References 111 publications

(196 reference statements)

Supporting

Mentioning

254

Contrasting

Unclassified

Order By: Relevance

“…A few examples of these molecular catalysts are described below as they have been reviewed in detail recently. 20 To date, Ru is the most widely used transition metal in water oxidation molecular catalysts. Ru complexes typically form stable metal-ligand bonds, which increase the stability of the reactive intermediates involved in water oxidation.…”

Section: Bio-inspired Molecular Catalystsmentioning

confidence: 99%

Molecular water-oxidation catalysts for photoelectrochemical cells

et al. 2009

View full text Add to dashboard Cite

Photoelectrochemical cells that efficiently split water into oxygen and hydrogen, "the fuel of the future", need to combine robust water oxidation catalysts at the anode (2H(2)O -> O-2 + 4H(+) + 4e(-)) with hydrogen reduction catalysts at the cathode (2H(+) + 2e(-) -> H-2). Both sets of catalysts will, ideally, operate at low overpotentials and employ light-driven or light-assisted processes. In this Perspective article, we focus on significant efforts to develop solid state materials and molecular coordination complexes as catalyst for water oxidation. We briefly review the field with emphasis on the various molecular catalysts that have been developed and then examine the activity of molecular catalysts in water oxidation following their attachment to conducting electrodes. For such molecular species to be useful in a solar water-splitting device it is preferable that they are securely and durably affixed to an electrode surface. We also consider recent developments aimed at combining the action of molecular catalysts with light absorption so that light driven water oxidation may be achieved. Photoelectrochemical cells that efficiently split water into oxygen and hydrogen, "the fuel of the future", need to combine robust water oxidation catalysts at the anode (2H 2 O → O 2 + 4H + + 4e -) with hydrogen reduction catalysts at the cathode (2H + + 2e -→ H 2 ). Both sets of catalysts will, ideally, operate at low overpotentials and employ light-driven or light-assisted processes. In this Perspective article, we focus on significant efforts to develop solid state materials and molecular coordination complexes as catalyst for water oxidation. We briefly review the field with emphasis on the various molecular catalysts that have been developed and then examine the activity of molecular catalysts in water oxidation following their attachment to conducting electrodes. For such molecular species to be useful in a solar water-splitting device it is preferable that they are securely and durably affixed to an electrode surface. We also consider recent developments aimed at combining the action of molecular catalysts with light absorption so that light driven water oxidation may be achieved.

show abstract

Section: Bio-inspired Molecular Catalystsmentioning

confidence: 99%

Molecular water-oxidation catalysts for photoelectrochemical cells

et al. 2009

View full text Add to dashboard Cite

show abstract

“…catalysis ͉ redox mediator ͉ electron transfer W ater oxidation is a key reaction in photosynthesis, the basis for most of life as we know it (1)(2)(3)(4)(5)(6)(7)(8). It is also a central reaction in artificial photosynthesis, an example being solardriven splitting of water into hydrogen and oxygen, 2 H 2 O 3 O 2 ϩ 2 H 2 (9)(10)(11).…”

mentioning

confidence: 99%

Mediator-assisted water oxidation by the ruthenium “blue dimer”cis,cis-[(bpy)₂(H₂O)RuORu(OH₂)(bpy)₂]⁴⁺

Concepcion

Jurss

Templeton

et al. 2008

Proc. Natl. Acad. Sci. U.S.A.

114

View full text Add to dashboard Cite

Light-driven water oxidation occurs in oxygenic photosynthesis in photosystem II and provides redox equivalents directed to photosystem I, in which carbon dioxide is reduced. Water oxidation is also essential in artificial photosynthesis and solar fuelforming reactions, such as water splitting into hydrogen and oxygen (2 H2O ؉ 4 h 3 O2 ؉ 2 H2) or water reduction of CO2 to methanol (2 H2O ؉ CO2 ؉ 6 h 3 CH3OH ؉ 3/2 O2), or hydrocarbons, which could provide clean, renewable energy. The ''blue ruthenium dimer,'' cis,cis-[(bpy)2(H2O)Ru III ORu III (OH2)(bpy)2] 4؉ , was the first well characterized molecule to catalyze water oxidation. On the basis of recent insight into the mechanism, we have devised a strategy for enhancing catalytic rates by using kinetically facile electron-transfer mediators. Rate enhancements by factors of up to Ϸ30 have been obtained, and preliminary electrochemical experiments have demonstrated that mediator-assisted electrocatalytic water oxidation is also attainable.catalysis ͉ redox mediator ͉ electron transfer W ater oxidation is a key reaction in photosynthesis, the basis for most of life as we know it (1-8). It is also a central reaction in artificial photosynthesis, an example being solardriven splitting of water into hydrogen and oxygen, 2 H 2 O 3 O 2 ϩ 2 H 2 (9-11). In natural photosynthesis, water oxidation occurs at photosystem II (PSII) through the Kok cycle after absorption of four photons. Detailed insight into how this reaction occurs is emerging on the basis of theoretical and spectroscopic studies and recent x-ray diffraction and extended x-ray absorption fine structure results to 3.0-Å resolution (12)(13)(14).Given the demands of the half reaction, 2 H 2 O 3 O 2 ϩ 4 H ϩ ϩ 4e Ϫ , with requirements for both 4e Ϫ /4H ϩ loss and OOO bond formation, water oxidation is difficult to achieve at a single catalyst site or cluster. In addition to PSII, water oxidation is also catalyzed by the ruthenium ''blue dimer'' cis,cis-[(bpy) 2 (H 2 O)Ru III ORu III (OH 2 )(bpy) 2 ] 4ϩ (bpy is 2,2Ј-bipyridine) and structurally related derivatives (15-21) (Fig. 1). Other catalysts based on iridium and ruthenium complexes and in rutheniumcontaining polyoxometalates have been reported recently (22-25).The low oxidation state Ru III -O-Ru III form of the ruthenium blue dimer undergoes oxidative activation by proton-coupled electron transfer (PCET) in which stepwise loss of electrons and protons occurs. PCET is essential, because it allows for the buildup of multiple oxidative equivalents at a single site or cluster without building up positive charge (21, 26). As shown by the results of pH-dependent electrochemical studies (16), loss of 4e Ϫ /4H ϩ occurs to give a reactive, transient intermediate followed by O 2 evolution.In the absence of a serendipitous discovery, mechanistic knowledge is required for the design of robust, long-lived catalysts for water oxidation. Such knowledge is also important for the microscopic reverse reaction, oxygen reduction to water, which occurs at the cathode (reducing e...

show abstract

“…A proposal mechanism was reported by Brudvig group for the reaction (Fig. 6) (Cady et al, 2008). Recently, Brudvig's group have reported the attachment of [(OH 2 )(terpy)Mn III (μ-O) 2 Mn IV (terpy)(OH 2 )] 3+ onto TiO 2 nanoparticles via direct adsorption.…”

Section: Functional Models For Biological Water Oxidizing Complexmentioning

confidence: 99%

“…There are a few manganese complexes that produce oxygen in the presence of different oxidants (Cady et al, 2008;Yagi & Kaneko, 2001;Ruttinger & Dismukes 1997). It is important to know that even if the oxidants may do donate O-atoms that end up in the product oxygen, can nevertheless play an important role in identifying potentially useful catalytic components for water photolysis and electrolysis.…”

Section: Functional Models For Biological Water Oxidizing Complexmentioning

confidence: 99%

See 1 more Smart Citation

Manganese Compounds as Water Oxidizing Catalysts in Artificial Photosynthesis

Najafpour¹

2012

Artificial Photosynthesis

View full text Add to dashboard Cite

Functional models for the oxygen-evolving complex of photosystem II

Cited by 384 publications

References 111 publications

Molecular water-oxidation catalysts for photoelectrochemical cells

Molecular water-oxidation catalysts for photoelectrochemical cells

Mediator-assisted water oxidation by the ruthenium “blue dimer”cis,cis-[(bpy)₂(H₂O)RuORu(OH₂)(bpy)₂]⁴⁺

Manganese Compounds as Water Oxidizing Catalysts in Artificial Photosynthesis

Contact Info

Product

Resources

About

Functional models for the oxygen-evolving complex of photosystem II

Cited by 384 publications

References 111 publications

Molecular water-oxidation catalysts for photoelectrochemical cells

Molecular water-oxidation catalysts for photoelectrochemical cells

Mediator-assisted water oxidation by the ruthenium “blue dimer”cis,cis-[(bpy)2(H2O)RuORu(OH2)(bpy)2]4+

Manganese Compounds as Water Oxidizing Catalysts in Artificial Photosynthesis

Contact Info

Product

Resources

About

Mediator-assisted water oxidation by the ruthenium “blue dimer”cis,cis-[(bpy)₂(H₂O)RuORu(OH₂)(bpy)₂]⁴⁺