TY - JOUR
T1 - Mimicking electron transfer reactions in photosystem II
T2 - Synthesis and photochemical characterization of a ruthenium(II) tris(bipyridyl) complex with a covalently linked tyrosine
AU - Magnuson, Ann
AU - Berglund, Helena
AU - Korall, Peter
AU - Hammarström, Leif
AU - Åkermark, Björn
AU - Styring, Stenbjörn
AU - Sun, Licheng
PY - 1997/12/4
Y1 - 1997/12/4
N2 - In the natural photosynthetic reaction center photosystem II, absorption of a photon leads to photooxidation of the primary electron donor:P680, which subsequently retrieves electrons from a tyrosyl residue, functioning as an interface to the oxygen-evolving manganese complex. In a first step toward mimicking these reactions, we have made a Ru(II)-polypyridine complex with an attached tyrosyl moiety. The photoexcited ruthenium complex played the role of P680 and was first oxidized by external accepters. Combined transient absorbance and EPR studies provided evidence that the Ru(III) formed was reduced by intramolecular electron transfer from the attached tyrosine, with a rate constant of 5 x 104 s-1. Thus we show that a tyrosine radical could be formed by light-induced electron transfer reactions, and we indicate future directions for developing a closer analogy with the photosystem II reactions.
AB - In the natural photosynthetic reaction center photosystem II, absorption of a photon leads to photooxidation of the primary electron donor:P680, which subsequently retrieves electrons from a tyrosyl residue, functioning as an interface to the oxygen-evolving manganese complex. In a first step toward mimicking these reactions, we have made a Ru(II)-polypyridine complex with an attached tyrosyl moiety. The photoexcited ruthenium complex played the role of P680 and was first oxidized by external accepters. Combined transient absorbance and EPR studies provided evidence that the Ru(III) formed was reduced by intramolecular electron transfer from the attached tyrosine, with a rate constant of 5 x 104 s-1. Thus we show that a tyrosine radical could be formed by light-induced electron transfer reactions, and we indicate future directions for developing a closer analogy with the photosystem II reactions.
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U2 - 10.1021/ja972161h
DO - 10.1021/ja972161h
M3 - Article
AN - SCOPUS:0030784901
VL - 119
SP - 10720
EP - 10725
JO - Journal of the American Chemical Society
JF - Journal of the American Chemical Society
SN - 0002-7863
IS - 44
ER -