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Mimicking electron transfer reactions in photosystem II: Synthesis and photochemical characterization of a ruthenium(II) tris(bipyridyl) complex with a covalently linked tyrosine

Magnuson, Ann LU ; Berglund, H; Korall, P; Hammarstrom, L; Akermark, B; Styring, Stenbjörn LU and Sun, LC (1997) In Journal of the American Chemical Society 119(44). p.10720-10725
Abstract
In the natural photosynthetic reaction center photosystem II, absorption of a photon leads to photooxidation of the primary electron donor P-680, 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 P-680 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 10(4) s(-1). Thus we show that a tyrosine... (More)
In the natural photosynthetic reaction center photosystem II, absorption of a photon leads to photooxidation of the primary electron donor P-680, 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 P-680 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 10(4) 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. (Less)
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author
organization
publishing date
type
Contribution to journal
publication status
published
subject
keywords
PHOTOSYNTHETIC OXYGEN EVOLUTION, Y-Z, MANGANESE CLUSTER, EXCITED-STATES, MODEL, METAL
in
Journal of the American Chemical Society
volume
119
issue
44
pages
10720 - 10725
publisher
The American Chemical Society
external identifiers
  • scopus:0030784901
ISSN
1520-5126
DOI
10.1021/ja972161h
language
English
LU publication?
yes
id
8dae25b6-af44-46b9-9e8b-fb160b203a7e (old id 127082)
date added to LUP
2007-07-06 10:51:33
date last changed
2017-10-08 04:27:08
@article{8dae25b6-af44-46b9-9e8b-fb160b203a7e,
  abstract     = {In the natural photosynthetic reaction center photosystem II, absorption of a photon leads to photooxidation of the primary electron donor P-680, 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 P-680 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 10(4) 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.},
  author       = {Magnuson, Ann and Berglund, H and Korall, P and Hammarstrom, L and Akermark, B and Styring, Stenbjörn and Sun, LC},
  issn         = {1520-5126},
  keyword      = {PHOTOSYNTHETIC OXYGEN EVOLUTION,Y-Z,MANGANESE CLUSTER,EXCITED-STATES,MODEL,METAL},
  language     = {eng},
  number       = {44},
  pages        = {10720--10725},
  publisher    = {The American Chemical Society},
  series       = {Journal of the American Chemical Society},
  title        = {Mimicking electron transfer reactions in photosystem II: Synthesis and photochemical characterization of a ruthenium(II) tris(bipyridyl) complex with a covalently linked tyrosine},
  url          = {http://dx.doi.org/10.1021/ja972161h},
  volume       = {119},
  year         = {1997},
}