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Mimicking photosystem II reactions in artificial photosynthesis: Ru(II)-polypyridine photosensitisers linked to tyrosine and manganese electron donors

Hammarström, Leif; Sun, Licheng; Åkermark, Björn and Styring, Stenbjörn LU (2000) In Catalysis Today 58(2-3). p.57-69
Abstract
The paper describes a project aiming at constructing functional mimics of the oxygen evolving complex in photosystem II, coupled to photoinduced charge separation. Biomimetic electron donors, manganese complexes and tyrosine, have been linked to a Ru(II)-polypyridine photosensitiser. Oxidation of the donors by intramolecular electron transfer from the photooxidised Ru(III) complex was demonstrated using optical flash photolysis and EPR experiments. A step-wise electron transfer Mn(III,III)->tyrosine->Ru(III) was demonstrated, in analogy to the reaction on the donor side of photosystem II. Electron transfer from the tyrosine to Ru(III) was coupled to tyrosine deprotonation. This resulted in a large reorganisation energy and thus a... (More)
The paper describes a project aiming at constructing functional mimics of the oxygen evolving complex in photosystem II, coupled to photoinduced charge separation. Biomimetic electron donors, manganese complexes and tyrosine, have been linked to a Ru(II)-polypyridine photosensitiser. Oxidation of the donors by intramolecular electron transfer from the photooxidised Ru(III) complex was demonstrated using optical flash photolysis and EPR experiments. A step-wise electron transfer Mn(III,III)->tyrosine->Ru(III) was demonstrated, in analogy to the reaction on the donor side of photosystem II. Electron transfer from the tyrosine to Ru(III) was coupled to tyrosine deprotonation. This resulted in a large reorganisation energy and thus a slow reaction rate, unless the tyrosine was hydrogen bonded or already deprotonated. A comparison with analogous reaction in photosystem II is made. Finally, light-induced oxidation of a manganese dimer linked to a Ru(II)-photosensitiser was observed. Preliminary results suggest the possibility of photooxidising manganese dimers in several steps, which is an important step towards water oxidation. (Less)
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organization
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type
Contribution to journal
publication status
published
subject
keywords
Electron transfer, Manganese, Ruthenium, Photochemistry, Artificial photosynthesis, Photosystem II
in
Catalysis Today
volume
58
issue
2-3
pages
57 - 69
publisher
Elsevier
external identifiers
  • scopus:0033740821
ISSN
0920-5861
DOI
10.1016/S0920-5861(00)00242-X
language
English
LU publication?
yes
id
9314cf73-c8d6-4917-a4a9-0017d6e56855 (old id 125104)
date added to LUP
2007-07-05 11:35:03
date last changed
2017-04-30 13:14:22
@article{9314cf73-c8d6-4917-a4a9-0017d6e56855,
  abstract     = {The paper describes a project aiming at constructing functional mimics of the oxygen evolving complex in photosystem II, coupled to photoinduced charge separation. Biomimetic electron donors, manganese complexes and tyrosine, have been linked to a Ru(II)-polypyridine photosensitiser. Oxidation of the donors by intramolecular electron transfer from the photooxidised Ru(III) complex was demonstrated using optical flash photolysis and EPR experiments. A step-wise electron transfer Mn(III,III)->tyrosine->Ru(III) was demonstrated, in analogy to the reaction on the donor side of photosystem II. Electron transfer from the tyrosine to Ru(III) was coupled to tyrosine deprotonation. This resulted in a large reorganisation energy and thus a slow reaction rate, unless the tyrosine was hydrogen bonded or already deprotonated. A comparison with analogous reaction in photosystem II is made. Finally, light-induced oxidation of a manganese dimer linked to a Ru(II)-photosensitiser was observed. Preliminary results suggest the possibility of photooxidising manganese dimers in several steps, which is an important step towards water oxidation.},
  author       = {Hammarström, Leif and Sun, Licheng and Åkermark, Björn and Styring, Stenbjörn},
  issn         = {0920-5861},
  keyword      = {Electron transfer,Manganese,Ruthenium,Photochemistry,Artificial photosynthesis,Photosystem II},
  language     = {eng},
  number       = {2-3},
  pages        = {57--69},
  publisher    = {Elsevier},
  series       = {Catalysis Today},
  title        = {Mimicking photosystem II reactions in artificial photosynthesis: Ru(II)-polypyridine photosensitisers linked to tyrosine and manganese electron donors},
  url          = {http://dx.doi.org/10.1016/S0920-5861(00)00242-X},
  volume       = {58},
  year         = {2000},
}