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The first room‐temperature X‐ray absorption spectra of higher oxidation states of the tetra‐manganese complex of photosystem II
Author(s) -
Haumann Michael,
Grabolle Markus,
Neisius Thomas,
Dau Holger
Publication year - 2002
Publication title -
febs letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.593
H-Index - 257
eISSN - 1873-3468
pISSN - 0014-5793
DOI - 10.1016/s0014-5793(02)02237-8
Subject(s) - manganese , chemistry , photosystem ii , absorption (acoustics) , absorption spectroscopy , absorption edge , spectral line , analytical chemistry (journal) , photochemistry , extended x ray absorption fine structure , materials science , photosynthesis , optics , physics , band gap , biochemistry , optoelectronics , organic chemistry , chromatography , astronomy , composite material
The manganese (Mn) complex of photosystem II catalyzes water oxidation. For the first time, its advancement through the reaction cycle was monitored by time‐resolved X‐ray absorption measurements at the Mn K‐edge at room temperature. The complex was stepped through its four oxidation states by nano‐second‐laser flashes applied to samples exposed to the X‐ray beam. Time courses of the X‐ray fluorescence intensity were recorded during a flash sequence. Extended X‐ray absorption fine‐structure spectra were recorded with the S 1 , S 2 , and S 3 oxidation states highly populated. The room temperature data is compatible with the formation of a third di‐μ‐oxo bridge between two Mn atoms upon the S 2 →S 3 transition.