A Gas-Phase Can Mn4-n O4+ Cluster Model for the Oxygen-Evolving Complex of Photosystem II.
Angew Chem Int Ed Engl
; 58(25): 8504-8509, 2019 06 17.
Article
em En
| MEDLINE
| ID: mdl-30985054
ABSTRACT
One of the fundamental processes in nature, the oxidation of water, is catalyzed by a small CaMn3 O4 â
MnO cluster located in photosystem II (PS II). Now, the first successful preparation of a series of isolated ligand-free tetrameric Can Mn4-n O4+ (n=0-4) cluster ions is reported, which are employed as structural models for the catalytically active site of PS II. Gas-phase reactivity experiments with D2 O and H218 O in an ion trap reveal the facile deprotonation of multiple water molecules via hydroxylation of the cluster oxo bridges for all investigated clusters. However, only the mono-calcium cluster CaMn3 O4+ is observed to oxidize water via elimination of hydrogen peroxide. First-principles density functional theory (DFT) calculations elucidate mechanistic details of the deprotonation and oxidation reactions mediated by CaMn3 O4+ as well as the role of calcium.
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Base de dados:
MEDLINE
Assunto principal:
Oxigênio
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Cálcio
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Complexo de Proteína do Fotossistema II
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Manganês
Idioma:
En
Ano de publicação:
2019
Tipo de documento:
Article