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Title: The Catalytic Manganese Cluster: Organization of the Metal Ions

Abstract

The light-induced oxidation of water to O{sub 2} is catalyzed by a four-manganese atom cluster associated with Photosystem II (PS II). This chapter summarizes ongoing investigations of the oxidation state, the structure and the associated cofactors calcium and chloride of the catalytic Mn cluster using X-ray and electron paramagnetic resonance (EPR) spectroscopy. Manganese K-edge X-ray spectroscopy, K{beta} X-ray emission spectroscopy (XES), and extended X-ray absorption fine structure (EXAFS) studies have not only determined the oxidation states and structural features, but also changes that occur in oxidation state of the Mn cluster and in its structural organization during the accumulation of oxidizing equivalents leading to O{sub 2} formation. Combining X-ray spectroscopy information with X-ray diffraction studies, and consistent with the available EPR data, we have succeeded in limiting the range of likely structures of the Mn cluster. EXAFS studies at the strontium and calcium K-edges have provided evidence that the catalytic center is a Mn/Ca heteronuclear complex. Based on the X-ray spectroscopy data, models for the structure and a mechanism for O{sub 2} evolution are presented.

Authors:
 [1]
  1. (LBNL)
Publication Date:
Research Org.:
Argonne National Lab. (ANL), Argonne, IL (United States). Advanced Photon Source (APS)
Sponsoring Org.:
USDOE
OSTI Identifier:
1008412
Resource Type:
Book
Resource Relation:
Related Information: Photosystem II The Light-Driven Water: Plastoquinone Oxidoreductase
Country of Publication:
United States
Language:
ENGLISH
Subject:
14 SOLAR ENERGY; MANGANESE COMPOUNDS; MOLECULAR CLUSTERS; WATER; OXIDATION; PHOTOSYNTHESIS; CATALYTIC EFFECTS; CALCIUM; CHLORIDES; MOLECULAR STRUCTURE; MORPHOLOGICAL CHANGES; VALENCE

Citation Formats

Yachandra, V.K. The Catalytic Manganese Cluster: Organization of the Metal Ions. United States: N. p., 2007. Web.
Yachandra, V.K. The Catalytic Manganese Cluster: Organization of the Metal Ions. United States.
Yachandra, V.K. Fri . "The Catalytic Manganese Cluster: Organization of the Metal Ions". United States. doi:.
@article{osti_1008412,
title = {The Catalytic Manganese Cluster: Organization of the Metal Ions},
author = {Yachandra, V.K.},
abstractNote = {The light-induced oxidation of water to O{sub 2} is catalyzed by a four-manganese atom cluster associated with Photosystem II (PS II). This chapter summarizes ongoing investigations of the oxidation state, the structure and the associated cofactors calcium and chloride of the catalytic Mn cluster using X-ray and electron paramagnetic resonance (EPR) spectroscopy. Manganese K-edge X-ray spectroscopy, K{beta} X-ray emission spectroscopy (XES), and extended X-ray absorption fine structure (EXAFS) studies have not only determined the oxidation states and structural features, but also changes that occur in oxidation state of the Mn cluster and in its structural organization during the accumulation of oxidizing equivalents leading to O{sub 2} formation. Combining X-ray spectroscopy information with X-ray diffraction studies, and consistent with the available EPR data, we have succeeded in limiting the range of likely structures of the Mn cluster. EXAFS studies at the strontium and calcium K-edges have provided evidence that the catalytic center is a Mn/Ca heteronuclear complex. Based on the X-ray spectroscopy data, models for the structure and a mechanism for O{sub 2} evolution are presented.},
doi = {},
journal = {},
number = ,
volume = ,
place = {United States},
year = {Fri Feb 09 00:00:00 EST 2007},
month = {Fri Feb 09 00:00:00 EST 2007}
}

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