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.
| Original language | English |
|---|---|
| Pages (from-to) | 2145-2160 |
| Number of pages | 16 |
| Journal | Spectrochimica Acta - Part A Molecular and Biomolecular Spectroscopy |
| Volume | 57 |
| Issue number | 11 |
| DOIs | |
| Publication status | Published - Sep 14 2001 |
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Keywords
- Artificial photosynthesis
- Electron transfer
- Manganese
- Photochemistry
- Photosystem II
- Ruthenium
ASJC Scopus subject areas
- Spectroscopy
Cite this
A biomimetic approach to artificial photosynthesis : Ru(II)-polypyridine photo-sensitisers linked to tyrosine and manganese electron donors. / Hammarström, L.; Sun, L.; Åkermark, B.; Styring, S.
In: Spectrochimica Acta - Part A Molecular and Biomolecular Spectroscopy, Vol. 57, No. 11, 14.09.2001, p. 2145-2160.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - A biomimetic approach to artificial photosynthesis
T2 - Ru(II)-polypyridine photo-sensitisers linked to tyrosine and manganese electron donors
AU - Hammarström, L.
AU - Sun, L.
AU - Åkermark, B.
AU - Styring, S.
PY - 2001/9/14
Y1 - 2001/9/14
N2 - 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.
AB - 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.
KW - Artificial photosynthesis
KW - Electron transfer
KW - Manganese
KW - Photochemistry
KW - Photosystem II
KW - Ruthenium
UR - http://www.scopus.com/inward/record.url?scp=0035860113&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=0035860113&partnerID=8YFLogxK
U2 - 10.1016/S1386-1425(01)00491-7
DO - 10.1016/S1386-1425(01)00491-7
M3 - Article
VL - 57
SP - 2145
EP - 2160
JO - Spectrochimica Acta - Part A: Molecular and Biomolecular Spectroscopy
JF - Spectrochimica Acta - Part A: Molecular and Biomolecular Spectroscopy
SN - 1386-1425
IS - 11
ER -