Oxidation State Changes of the Mn4Ca Cluster in PhotosystemII
A detailed electronic structure of the Mn4Ca cluster isrequired before two key questions for understanding the mechanism ofphotosynthetic water oxidation can be addressed. They are whether allfour oxidizing equivalents necessary to oxidize water to O2 accumulate onthe four Mn ions of the OEC, or do some ligand-centered oxidations takeplace before the formation and release of O2 during the S3 ->[S4]->S0 transition, and what are the oxidation state assignments for theMn during S-state advancement. X-ray absorption and emissi onspectroscopy of Mn, including the newly introduced resonant inelasticX-ray scattering spectroscopy have been used to address these questions.The present state of understanding of the electronic structure andoxidation state changes of the Mn4Ca cluster in all the S-states,particularly in the S2 to S3 transition, derived from these techniques isdescribed in this review.
- Research Organization:
- Ernest Orlando Lawrence Berkeley NationalLaboratory, Berkeley, CA (US)
- Sponsoring Organization:
- USDOE Director, Office of Science; National Institutes ofHealth
- DOE Contract Number:
- AC02-05CH11231
- OSTI ID:
- 923650
- Report Number(s):
- LBNL--62490; BnR: 400412000
- Journal Information:
- Photosynthesis Research, Journal Name: Photosynthesis Research Journal Issue: 3 Vol. 92; ISSN PHRSDI; ISSN 0166-8595
- Country of Publication:
- United States
- Language:
- English
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