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 photosensitizer. Oxidation of the donors by intramolecular electron transfer from the photooxidized 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 reorganization 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)-photosensitizer was observed. Preliminary results suggest the possibility of photooxidizing manganese dimers in several steps, which is an important step towards water oxidation.
| Original language | English |
|---|---|
| Pages (from-to) | 57-69 |
| Number of pages | 13 |
| Journal | Catalysis Today |
| Volume | 58 |
| Issue number | 2 |
| DOIs | |
| Publication status | Published - May 12 2000 |
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ASJC Scopus subject areas
- Catalysis
- Process Chemistry and Technology
Cite this
Mimicking photosystem II reactions in artificial photosynthesis : Ru(II)-polypyridine photosensitizers linked to tyrosine and manganese electron donors. / Hammarström, Leif; Sun, Licheng; Åkermark, Björn; Styring, Stenbjörn.
In: Catalysis Today, Vol. 58, No. 2, 12.05.2000, p. 57-69.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Mimicking photosystem II reactions in artificial photosynthesis
T2 - Ru(II)-polypyridine photosensitizers linked to tyrosine and manganese electron donors
AU - Hammarström, Leif
AU - Sun, Licheng
AU - Åkermark, Björn
AU - Styring, Stenbjörn
PY - 2000/5/12
Y1 - 2000/5/12
N2 - 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 photosensitizer. Oxidation of the donors by intramolecular electron transfer from the photooxidized 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 reorganization 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)-photosensitizer was observed. Preliminary results suggest the possibility of photooxidizing manganese dimers in several steps, which is an important step towards water oxidation.
AB - 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 photosensitizer. Oxidation of the donors by intramolecular electron transfer from the photooxidized 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 reorganization 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)-photosensitizer was observed. Preliminary results suggest the possibility of photooxidizing manganese dimers in several steps, which is an important step towards water oxidation.
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U2 - 10.1016/S0920-5861(00)00242-X
DO - 10.1016/S0920-5861(00)00242-X
M3 - Article
VL - 58
SP - 57
EP - 69
JO - Catalysis Today
JF - Catalysis Today
SN - 0920-5861
IS - 2
ER -