Uncovering the Role of Oxygen Atom Transfer in Ru-Based Catalytic Water Oxidation.
The realization of artificial photosynthesis carries the promise of cheap and abundant energy, however, significant advances in the rational design of water oxidation catalysts are required. Detailed information on the structure of the catalyst under reaction conditions and mechanisms of O-O bond fo...
| Publicado en: | Journal of the American Chemical Society Vol. 138; no. 48; pp. 15605 - 15617 |
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| Autores principales: | , , , , , , |
| Formato: | Artículo |
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American Chemical Society
12/7/2016
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| Materias: | |
| Acceso en línea: | Ver este registro en EBSCOhost |
| fields | @attributes: recordID: 1 pdfLink: plink: https://search.ebscohost.com/login.aspx?direct=true&db=hlh&AN=120088014&site=ehost-live header: @attributes: shortDbName: hlh uiTerm: 120088014 longDbName: Humanities International Complete uiTag: AN controlInfo: bkinfo: jinfo: jid: 00027863 ACS jtl: Journal of the American Chemical Society issn: 00027863 maglogo: N pubinfo: dt: 12/7/2016 vid: 138 iid: 48 pid: 997 pub: American Chemical Society artinfo: ui: 120088014 10.1021/jacs.6b08409 ppf: 15605 ppct: 12 formats: tig: atl: Uncovering the Role of Oxygen Atom Transfer in Ru-Based Catalytic Water Oxidation. aug: au: Moonshiram, Dooshaye Pineda-Galvan, Yuliana Erdman, Darren Palenik, Mark Zong, Ruifa Thummel, Randolph Pushkar, Yulia affil: Department of Physics and Astronomy, Purdue University, 525 Northwestern Avenue, West Lafayette, Indiana 47907, United States Chemical Sciences and Engineering Division, Argonne National Laboratory, 9700 S. Cass Avenue, Lemont, Illinois 60439, United States Code 6189, Chemistry Division, Naval Research Laboratory, 4555 Overlook Avenue SW, Washington, DC 20375, United States Department of Chemistry, University of Houston, Houston, Texas 77204-5003, United States su: Artificial photosynthesis Oxidation of water Density functional theory Electron paramagnetic resonance X-ray absorption Raman spectroscopy sug: subj: Artificial photosynthesis Oxidation of water Density functional theory Electron paramagnetic resonance X-ray absorption Raman spectroscopy ab: The realization of artificial photosynthesis carries the promise of cheap and abundant energy, however, significant advances in the rational design of water oxidation catalysts are required. Detailed information on the structure of the catalyst under reaction conditions and mechanisms of O-O bond formation should be obtained. Here, we used a combination of electron paramagnetic resonance (EPR), stopped flow freeze quench on a millisecond-second time scale, X-ray absorption (XAS), resonance Raman (RR) spectroscopy, and density functional theory (DFT) to follow the dynamics of the Ru-based single site catalyst, [Ru(NPM)(4-pic)(HO)] (NPM = 4-t-butyl-2,6-di(1',8'-naphthyrid-2'-yl)pyridine, pic = 4-picoline), under the water oxidation conditions. We report a unique EPR signal with g-tensor, g = 2.30, g = 2.18, and g = 1.83 which allowed us to observe fast dynamics of oxygen atom transfer from the Ru═O oxo species to the uncoordinated nitrogen of the NPM ligand. In few seconds, the NPM ligand modification results in [Ru(NPM-NO)(4-pic)(HO)] and [Ru(NPM-NO,NO)(4-pic)] complexes. A proposed [Ru(NPM)(4-pic)═O] intermediate was not detected under the tested conditions. We demonstrate that while the proximal base might be beneficial in O-O bond formation via nucleophilic water attack on an oxo species as shown by DFT, the noncoordinating nitrogen is impractical as a base in water oxidation catalysts due to its facile conversion to the N-O group. This study opens new horizons for understanding the real structure of Ru catalysts under water oxidation conditions and points toward the need to further investigate the role of the N-O ligand in promoting water oxidation catalysis. pubtype: Academic Journal doctype: Article src: R language: English refInfo: copyright: @attributes: flag: Y dt: @attributes: year: 2016 holdings: @attributes: islocal: N |
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