Change search
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf
A Dinuclear Ruthenium-Based Water Oxidation Catalyst: Use of Non-Innocent Ligand Frameworks for Promoting Multi-Electron Reactions
Stockholm University, Faculty of Science, Department of Organic Chemistry.
Stockholm University, Faculty of Science, Department of Organic Chemistry.
Stockholm University, Faculty of Science, Department of Organic Chemistry. Huazhong University of Science & Technology, People's Republic of China.
Stockholm University, Faculty of Science, Department of Organic Chemistry.
Show others and affiliations
2015 (English)In: Chemistry - A European Journal, ISSN 0947-6539, E-ISSN 1521-3765, Vol. 21, no 28, 10039-10048 p.Article in journal (Refereed) Published
Abstract [en]

Insight into how H2O is oxidized to O-2 is envisioned to facilitate the rational design of artificial water oxidation catalysts, which is a vital component in solar-to-fuel conversion schemes. Herein, we report on the mechanistic features associated with a dinuclear Ru-based water oxidation catalyst. The catalytic action of the designed Ru complex was studied by the combined use of high-resolution mass spectrometry, electrochemistry, and quantum chemical calculations. Based on the obtained results, it is suggested that the designed ligand scaffold in Ru complex 1 has a non-innocent behavior, in which metal-ligand cooperation is an important part during the four-electron oxidation of H2O. This feature is vital for the observed catalytic efficiency and highlights that the preparation of catalysts housing non-innocent molecular frameworks could be a general strategy for accessing efficient catalysts for activation of H2O.

Place, publisher, year, edition, pages
2015. Vol. 21, no 28, 10039-10048 p.
Keyword [en]
density functional calculations, electrochemistry, ligands, ruthenium, water splitting
National Category
Organic Chemistry
Research subject
Organic Chemistry
Identifiers
URN: urn:nbn:se:su:diva-119297DOI: 10.1002/chem.201406613ISI: 000357026700014OAI: oai:DiVA.org:su-119297DiVA: diva2:844208
Available from: 2015-08-04 Created: 2015-08-03 Last updated: 2017-12-04Bibliographically approved
In thesis
1. Development of Ruthenium Catalysts for Water Oxidation
Open this publication in new window or tab >>Development of Ruthenium Catalysts for Water Oxidation
2016 (English)Doctoral thesis, comprehensive summary (Other academic)
Abstract [en]

An increasing global energy demand requires alternative fuel sources. A promising method is artificial photosynthesis. Although, the artificial processes are different from the natural photosynthetic process, the basic principles are the same, i.e. to split water and to convert solar energy into chemical energy. The energy is stored in bonds, which can at a later stage be released upon combustion. The bottleneck in the artificial systems is the water oxidation. The aim of this research has been to develop catalysts for water oxidation that are stable, yet efficient. The molecular catalysts are comprised of organic ligands that ultimately are responsible for the catalyst structure and activity. These ligands are often based on polypyridines or other nitrogen-containing aromatic compounds. This thesis describes the development of molecular ruthenium catalysts and the evaluation of their ability to mediate chemical and photochemical oxidation of water. Previous work from our group has shown that the introduction of negatively charged groups into the ligand frameworks lowers the redox potentials of the metal complexes. This is beneficial as it makes it possible to drive water oxidation with [Ru(bpy)3]3+-type oxidants (bpy = 2,2’-bipyridine), which can be photochemically generated from the corresponding [Ru(bpy)3]2+ complex. Hence, all the designed ligands herein contain negatively charged groups in the coordination site for ruthenium.

The first part of this thesis describes the development of two mononuclear ruthenium complexes and the evaluation of these for water oxidation. Both complexes displayed low redox potentials, allowing for water oxidation to be driven either chemically or photochemically using the mild one-electron oxidant [Ru(bpy)3]3+.

The second part is a structure–activity relationship study on several analogues of mononuclear ruthenium complexes. The complexes were active for water oxidation and the redox potentials of the analogues displayed a linear relationship with the Hammet σmeta parameter. It was also found that the complexes form high-valent Ru(VI) species, which are responsible for mediating O–O bond formation.

The last part of the thesis describes the development of a dinuclear ruthenium complex and the catalytic performance for chemical and photochemical water oxidation. It was found that the complex undergoes O–O bond formation via a bridging peroxide intermediate, i.e. an I2M–type mechanism.

Place, publisher, year, edition, pages
Stockholm: Department of Organic Chemistry, Stockholm University, 2016. 67 p.
Keyword
homogeneous catalysis, O-O bond formation, photocatalysis, ruthenium, water oxidation
National Category
Organic Chemistry
Research subject
Organic Chemistry
Identifiers
urn:nbn:se:su:diva-134824 (URN)978-91-7649-508-7 (ISBN)978-91-7649-509-4 (ISBN)
Public defence
2016-12-09, Magnéli Hall, Arrhenius Laboratory, Svante Arrhenius väg 16 B, Stockholm, 10:00 (English)
Opponent
Supervisors
Available from: 2016-11-16 Created: 2016-10-19 Last updated: 2016-11-04Bibliographically approved

Open Access in DiVA

No full text

Other links

Publisher's full text

Search in DiVA

By author/editor
Laine, Tanja M.Kärkäs, Markus D.Liao, Rong-ZhenSiegbahn, Per E. M.Åkermark, Björn
By organisation
Department of Organic Chemistry
In the same journal
Chemistry - A European Journal
Organic Chemistry

Search outside of DiVA

GoogleGoogle Scholar

doi
urn-nbn

Altmetric score

doi
urn-nbn
Total: 66 hits
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf