Structure and redox properties of the water-oxidation catalyst [(bpy)2(OH2)RuORu(OH2)(bpy)2]4+

Gilbert, John A.; Eggleston, Drake S.; Murphy, W. Rorer; Geselowitz, David B.; Gersten, Susan W.; Hodgson, Derek J.; Meyer, Thomas J.

doi:10.1021/ja00299a017

Cited by 505 publications

(528 citation statements)

References 6 publications

(8 reference statements)

Supporting

Mentioning

497

Contrasting

Unclassified

Order By: Relevance

“…Finally, a great deal of work has been done to design heterogeneous systems that catalyze water oxidation. 2 ] +4 (where bpy is 2,2'-bipyridine) (1) is the first example of a homogeneous water oxidation catalyst [51,52]. Meyer et al reported (1) in the early 1980's as a water-oxidation catalyst capable of a moderate number of turnovers ( Table 1).…”

Section: Functional Modelsmentioning

confidence: 99%

See 1 more Smart Citation

Functional models for the oxygen-evolving complex of photosystem II

Cady

Crabtree

Brudvig

2008

Coordination Chemistry Reviews

388

255

View full text Add to dashboard Cite

In the last ten years, a number of advances have been made in the study of the oxygen-evolving complex (OEC) of photosystem II (PSII). Along with this new understanding of the natural system has come rapid advance in chemical models of this system. The advance of PSII model chemistry is seen most strikingly in the area of functional models where the few known systems available when this topic was last reviewed has grown into two families of model systems. In concert with this work, numerous mechanistic proposals for photosynthetic water oxidation have been proposed. Here, we review the recent efforts in functional model chemistry of the oxygen-evolving complex of photosystem II.

show abstract

Section: Functional Modelsmentioning

confidence: 99%

“…Complex 1 has yielded water-oxidation catalysis by using a number of different primary oxidants including Co 3+ [62], Ce IV [52,63,64], and electrochemical oxidation [51,52,57,61,65]. Using these one-electron oxidant systems has enabled the identification of every oxidation state of 1 between (III,III) and (V,V) [61].…”

Section: Oxo-bridged Ruthenium Dimers-thementioning

confidence: 99%

Functional models for the oxygen-evolving complex of photosystem II

Cady

Crabtree

Brudvig

2008

Coordination Chemistry Reviews

388

255

View full text Add to dashboard Cite

show abstract

“…Geometric constraints imposed by the ancillary ligands and the m-oxo bridge prevent oxygen atoms from attaining the correct geometry to form an O-O bond. It has been estimated that rotation about the m-O bond to yield an eclipsed geometry of the M-O vectors still places the O atoms 3.2 Å apart (Gilbert et al 1985). Coupling at this distance would require a significant distortion or the participation of water to mediate the radical coupling.…”

Section: Experimental Realization Of Metal-oxo Cofactors In Differentmentioning

confidence: 99%

A ligand field chemistry of oxygen generation by the oxygen-evolving complex and synthetic active sites

Betley

Surendranath

Childress

et al. 2007

Phil. Trans. R. Soc. B

View full text Add to dashboard Cite

Oxygen-oxygen bond formation and O 2 generation occur from the S 4 state of the oxygen-evolving complex (OEC). Several mechanistic possibilities have been proposed for water oxidation, depending on the formal oxidation state of the Mn atoms. All fall under two general classifications: the AB mechanism in which nucleophilic oxygen (base, B) attacks electrophilic oxygen (acid, A) of the Mn 4 Ca cluster or the RC mechanism in which radical-like oxygen species couple within OEC. The critical intermediate in either mechanism involves a metal oxo, though the nature of this oxo for AB and RC mechanisms is disparate. In the case of the AB mechanism, assembly of an even-electron count, high-valent metal-oxo proximate to a hydroxide is needed whereas, in an RC mechanism, two odd-electron count, high-valent metal oxos are required. Thus the two mechanisms give rise to very different design criteria for functional models of the OEC active site. This discussion presents the electron counts and ligand geometries that support metal oxos for AB and RC O-O bond-forming reactions. The construction of architectures that bring two oxygen functionalities together under the purview of the AB and RC scenarios are described.

show abstract

“…In the past decades, a number of experimental and theoretical studies (11)(12)(13)(14)(15)(16)(17)(18)(19)(20)(21)(22)(23)(24)(25)(26)(27)(28)(29) have been performed to design artificial photosynthetic systems that mimic native PSII systems. Many binuclear transition-metal catalysts such as LðH 2 OÞM-O-MðOH 2 ÞL or LðH 2 OÞM-BL-MðOH 2 Þ (where L and BL are nonbridging and bridging organic ligands, respectively) were prepared and characterized for their catalytic properties toward water oxidation (11)(12)(13)(14)(15)(16)(17)(18)(19)(20)(21).…”

mentioning

confidence: 99%

Similarities of artificial photosystems by ruthenium oxo complexes and native water splitting systems

Tanaka

Isobe

Yamanaka

et al. 2012

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

View full text Add to dashboard Cite

The nature of chemical bonds of ruthenium(Ru)-quinine(Q) complexes, mononuclear ½RuðtrpyÞð3,5-t-Bu 2 QÞðOH 2 Þ ðClO 4 Þ 2 (trpy ¼ 2,2 0 : 6 0 ,2 0 0 -terpyridine, 3,5-di-tert-butyl-1,2-benzoquinone) (1), and binuclear ½Ru 2 ðbtpyanÞð3,6-di-Bu 2 QÞ 2 ðOH 2 Þ 2þ ðbtpyan ¼ 1,8-bisð2,2 0 : 6 0 ,2 0 0 -terpyrid-4 0 -ylÞanthracene, 3,6-t-Bu 2 Q ¼ 3,6-di-tertbutyl-1,2-benzoquinone) (2), has been investigated by broken-symmetry (BS) hybrid density functional (DFT) methods. BS DFT computations for the Ru complexes have elucidated that the closed-shell structure (2b) Ru(II)-Q complex is less stable than the open-shell structure (2bb) consisting of Ru(III) and semiquinone (SQ) radical fragments. These computations have also elucidated eight different electronic and spin structures of tetraradical intermediates that may be generated in the course of water splitting reaction. The Heisenberg spin Hamiltonian model for these species has been derived to elucidate six different effective exchange interactions (J) for four spin systems. Six J values have been determined using total energies of the eight (or seven) BS solutions for different spin configurations. The natural orbital analyses of these BS DFTsolutions have also been performed in order to obtain natural orbitals and their occupation numbers, which are useful for the lucid understanding of the nature of chemical bonds of the Ru complexes. Implications of the computational results are discussed in relation to the proposed reaction mechanisms of water splitting reaction in artificial photosynthesis systems and the similarity between artificial and native water splitting systems.four redox center | manganese clusters | water oxidation | oxyl radical | O-O bond formation P hotosynthesis is one of the most important chemical processes on our planet. Extensive experimental studies (1-6) on the process have revealed that oxygenic photosynthesis involves several protein-cofactor complexes embedded in the photosynthetic thylakoid membranes of plants, green algae, and cyanobacteria. Among these complexes, photosystem II (PSII) has a prominent role because it catalyzes the oxidation of water (, which is the prerequisite for all aerobic life. The main cyclic process to catalyze the water-oxidation consists of successive four steps, which is referred to as the Kok cycle (6). During this process, the oxygen-evolving complex (OEC), the catalyst of the water oxidation reaction, takes five oxidation states (S 0 -S 4 ). The OEC in PSII contains an inorganic cluster consisting of four manganese ions and one calcium ion that are bridged by at least five oxygens; the active site is therefore expressed with the CaMn 4 O 5 cluster (3) (5). Very recently, the electronic structure and reactivity of 3 (7-10) have been elucidated based on the new high-resolution X-ray structure (5).In the past decades, a number of experimental and theoretical studies (11-29) have been performed to design artificial photosynthetic systems that mimic native PSII systems. Many binuclear transition-metal catalysts s...

show abstract

Structure and redox properties of the water-oxidation catalyst [(bpy)2(OH2)RuORu(OH2)(bpy)2]4+

Cited by 505 publications

References 6 publications

Functional models for the oxygen-evolving complex of photosystem II

Functional models for the oxygen-evolving complex of photosystem II

A ligand field chemistry of oxygen generation by the oxygen-evolving complex and synthetic active sites

Similarities of artificial photosystems by ruthenium oxo complexes and native water splitting systems

Contact Info

Product

Resources

About