Abstract
As part of a project aimed at developing models for photosystem II (PSII) in green plants, we have prepared a series of model compounds (7, 8, and 13). In these compounds, a photosensitizer, ruthenium(II) tris(bipyridyl) complex (to mimic the function of P680 in PSII), was covalently linked to a manganese(II) ion through different bridging ligands. The structures of the compounds were characterized by electron paramagnetic resonance measurements and electrospray ionization mass spectrometry. The interaction between the ruthenium and manganese moleties within the complex was probed by steady- state and time-resolved emission measurements. When the binuclear complexes are exposed to flash photolysis in the presence of an electron acceptor such as methylviologen (MV2+), it could be shown that after the initial electron transfer from the excited state of Ru(II) in compound 7, forming Ru(III) and MV+. , an intramolecular electron transfer from coordinated Mn(II) to the photogenerated Ru(III) occurred with a first-order rate constant of 1.8 x 105 s-1, regenerating Ru(II). This is believed to be the first supramolecular system where a manganese complex has been used as an electron donor to a photo-oxidized photosensitizer. Possible extensions to develop the manganese donor, and thus to approach the function of reaction center in PSII, are indicated.
| Original language | English |
|---|---|
| Pages (from-to) | 6996-7004 |
| Number of pages | 9 |
| Journal | Journal of the American Chemical Society |
| Volume | 119 |
| Issue number | 30 |
| DOIs | |
| Publication status | Published - Jul 30 1997 |
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Binuclear, ruthenium - manganese complexes as simple artificial models, for photosystem II in green plants. / Sun, Licheng; Berglund, Helena; Davydov, Roman; Norrby, Thomas; Hammarström, Leif; Korall, Peter; Börje, Anna; Philouze, Christian; Berg, Katja; Tran, Anh; Andersson, Michael; Stenhagen, Gunnar; Mårtensson, Jerker; Almgren, Mats; Styring, Stenbjörn; Åkermark, Björn.
In: Journal of the American Chemical Society, Vol. 119, No. 30, 30.07.1997, p. 6996-7004.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Binuclear, ruthenium - manganese complexes as simple artificial models, for photosystem II in green plants
AU - Sun, Licheng
AU - Berglund, Helena
AU - Davydov, Roman
AU - Norrby, Thomas
AU - Hammarström, Leif
AU - Korall, Peter
AU - Börje, Anna
AU - Philouze, Christian
AU - Berg, Katja
AU - Tran, Anh
AU - Andersson, Michael
AU - Stenhagen, Gunnar
AU - Mårtensson, Jerker
AU - Almgren, Mats
AU - Styring, Stenbjörn
AU - Åkermark, Björn
PY - 1997/7/30
Y1 - 1997/7/30
N2 - As part of a project aimed at developing models for photosystem II (PSII) in green plants, we have prepared a series of model compounds (7, 8, and 13). In these compounds, a photosensitizer, ruthenium(II) tris(bipyridyl) complex (to mimic the function of P680 in PSII), was covalently linked to a manganese(II) ion through different bridging ligands. The structures of the compounds were characterized by electron paramagnetic resonance measurements and electrospray ionization mass spectrometry. The interaction between the ruthenium and manganese moleties within the complex was probed by steady- state and time-resolved emission measurements. When the binuclear complexes are exposed to flash photolysis in the presence of an electron acceptor such as methylviologen (MV2+), it could be shown that after the initial electron transfer from the excited state of Ru(II) in compound 7, forming Ru(III) and MV+. , an intramolecular electron transfer from coordinated Mn(II) to the photogenerated Ru(III) occurred with a first-order rate constant of 1.8 x 105 s-1, regenerating Ru(II). This is believed to be the first supramolecular system where a manganese complex has been used as an electron donor to a photo-oxidized photosensitizer. Possible extensions to develop the manganese donor, and thus to approach the function of reaction center in PSII, are indicated.
AB - As part of a project aimed at developing models for photosystem II (PSII) in green plants, we have prepared a series of model compounds (7, 8, and 13). In these compounds, a photosensitizer, ruthenium(II) tris(bipyridyl) complex (to mimic the function of P680 in PSII), was covalently linked to a manganese(II) ion through different bridging ligands. The structures of the compounds were characterized by electron paramagnetic resonance measurements and electrospray ionization mass spectrometry. The interaction between the ruthenium and manganese moleties within the complex was probed by steady- state and time-resolved emission measurements. When the binuclear complexes are exposed to flash photolysis in the presence of an electron acceptor such as methylviologen (MV2+), it could be shown that after the initial electron transfer from the excited state of Ru(II) in compound 7, forming Ru(III) and MV+. , an intramolecular electron transfer from coordinated Mn(II) to the photogenerated Ru(III) occurred with a first-order rate constant of 1.8 x 105 s-1, regenerating Ru(II). This is believed to be the first supramolecular system where a manganese complex has been used as an electron donor to a photo-oxidized photosensitizer. Possible extensions to develop the manganese donor, and thus to approach the function of reaction center in PSII, are indicated.
UR - http://www.scopus.com/inward/record.url?scp=0030847092&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=0030847092&partnerID=8YFLogxK
U2 - 10.1021/ja962511k
DO - 10.1021/ja962511k
M3 - Article
AN - SCOPUS:0030847092
VL - 119
SP - 6996
EP - 7004
JO - Journal of the American Chemical Society
JF - Journal of the American Chemical Society
SN - 0002-7863
IS - 30
ER -