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A biomimetic approach to artificial photosynthesis: Ru(II)-polypyridine photo-sensitisers linked to tyrosine and manganese electron donors

Hammarström, Leif; Sun, Licheng; Åkermark, Björn and Styring, Stenbjörn LU (2001) In Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy 57(11). p.2145-2160
Abstract
The paper describes recent advances towards the construction of functional mimics of the oxygen evolving complex in photosystem II (PSII) that are coupled to photoinduced charge separation. Some key principles of PSII and artificial systems for light-induced charge accumulation are discussed. Systems are described where 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 photo-oxidised Ru(III) complex has been studied using optical flash photolysis and EPR experiments. A step-wise electron transfer Mn2(III,III)->tyrosine->Ru(III) has been demonstrated, in analogy to the reaction on the donor side... (More)
The paper describes recent advances towards the construction of functional mimics of the oxygen evolving complex in photosystem II (PSII) that are coupled to photoinduced charge separation. Some key principles of PSII and artificial systems for light-induced charge accumulation are discussed. Systems are described where 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 photo-oxidised Ru(III) complex has been studied using optical flash photolysis and EPR experiments. A step-wise electron transfer Mn2(III,III)->tyrosine->Ru(III) has been demonstrated, in analogy to the reaction on the donor side of PSII. 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 reactions in PSII is made. Finally, light-induced oxidation of a manganese dimer linked to a Ru(II)-photosensitiser has been observed. Preliminary results suggest the possibility of photo-oxidising manganese dimers in several steps, which is an important advancement towards water oxidation. (Less)
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organization
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type
Contribution to journal
publication status
published
subject
keywords
Artificial photosynthesis, Photosystem II, Electron transfer, Manganese, Ruthenium, Photochemistry
in
Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy
volume
57
issue
11
pages
2145 - 2160
publisher
Elsevier
external identifiers
  • scopus:0035860113
ISSN
1386-1425
DOI
10.1016/S1386-1425(01)00491-7
language
English
LU publication?
yes
id
121b0bea-655d-4e18-8cb6-a07152a63f99 (old id 124991)
date added to LUP
2007-07-05 11:38:43
date last changed
2018-01-07 09:31:38
@article{121b0bea-655d-4e18-8cb6-a07152a63f99,
  abstract     = {The paper describes recent advances towards the construction of functional mimics of the oxygen evolving complex in photosystem II (PSII) that are coupled to photoinduced charge separation. Some key principles of PSII and artificial systems for light-induced charge accumulation are discussed. Systems are described where 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 photo-oxidised Ru(III) complex has been studied using optical flash photolysis and EPR experiments. A step-wise electron transfer Mn2(III,III)->tyrosine->Ru(III) has been demonstrated, in analogy to the reaction on the donor side of PSII. 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 reactions in PSII is made. Finally, light-induced oxidation of a manganese dimer linked to a Ru(II)-photosensitiser has been observed. Preliminary results suggest the possibility of photo-oxidising manganese dimers in several steps, which is an important advancement towards water oxidation.},
  author       = {Hammarström, Leif and Sun, Licheng and Åkermark, Björn and Styring, Stenbjörn},
  issn         = {1386-1425},
  keyword      = {Artificial photosynthesis,Photosystem II,Electron transfer,Manganese,Ruthenium,Photochemistry},
  language     = {eng},
  number       = {11},
  pages        = {2145--2160},
  publisher    = {Elsevier},
  series       = {Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy},
  title        = {A biomimetic approach to artificial photosynthesis: Ru(II)-polypyridine photo-sensitisers linked to tyrosine and manganese electron donors},
  url          = {http://dx.doi.org/10.1016/S1386-1425(01)00491-7},
  volume       = {57},
  year         = {2001},
}