Relative energies among proton-shifted S2 isomers in the photosystem II revealed by DLPNO coupled cluster and hybrid DFT calculations. Proton transfer coupled spin transitions of the CaMn4Ox cluster in OEC of PSII

2022 ◽  
pp. 139357
Author(s):  
Koichi Miyagawa ◽  
Mitsuo Shoji ◽  
Hiroshi Isobe ◽  
Takashi Kawakami ◽  
Takahito Nakajima ◽  
...  
Keyword(s):  
Photosystem Ii ◽  
Proton Transfer ◽  
Dft Calculations ◽  
Coupled Cluster ◽  
Spin Transitions

Unexpected concerted two-proton transfer for amination of formic acid to formamide catalysed by Mn bipyridinol complexes

2018 ◽  
Vol 8 (22) ◽  
pp. 5735-5739 ◽  
Author(s):  
Xiuli Yan ◽  
Hongyu Ge ◽  
Xinzheng Yang
Keyword(s):  
Proton Transfer ◽  
Dft Calculations ◽  
Formic Acid ◽  
Transfer Mechanism

DFT calculations reveal a concerted two-proton transfer mechanism for the activation of diethylamine and formic acid, as well as the formation of formamide and water catalysed by Mn bipyridinol complexes.

1H–31P HETCOR NMR elucidates the nature of acid sites in zeolite HZSM-5 probed with trimethylphosphine oxide

2019 ◽  
Vol 55 (84) ◽  
pp. 12635-12638 ◽  
Author(s):  
Carlos Bornes ◽  
Mariana Sardo ◽  
Zhi Lin ◽  
Jeffrey Amelse ◽  
Auguste Fernandes ◽  
...  
Keyword(s):  
Proton Transfer ◽  
Dft Calculations ◽  
Acid Sites ◽  
Transfer Mechanism ◽  
Structural Insight ◽  
Insight Into

2D 1H–31P NMR and DFT calculations extend the understanding of TMPO:Brønsted complexes formed at HZSM-5 zeolite surfaces, providing structural insight into the proton-transfer mechanism.

scholarly journals Rigidly hydrogen-bonded water molecules facilitate proton transfer in photosystem II

2020 ◽  
Vol 22 (28) ◽  
pp. 15831-15841
Author(s):  
Naoki Sakashita ◽  
Hiroshi Ishikita ◽  
Keisuke Saito
Keyword(s):  
Photosystem Ii ◽  
Proton Transfer ◽  
Water Molecules ◽  
Hydrogen Bonded

In the channel of photosystem II, rigidly hydrogen-bonded water molecules facilitate the Grotthuss-like proton transfer, whereas flexible water molecules prevent proton transfer in the channel of aquaporin.

scholarly journals Bicarbonate rescues damaged proton-transfer pathway in photosystem II

2019 ◽  
Vol 1860 (8) ◽  
pp. 611-617 ◽  
Author(s):  
Gourab Banerjee ◽  
Ipsita Ghosh ◽  
Christopher J. Kim ◽  
Richard J. Debus ◽  
Gary W. Brudvig
Keyword(s):  
Photosystem Ii ◽  
Proton Transfer

Charge Recombination and Proton Transfer in Manganese-Depleted Photosystem II†

Biochemistry ◽  
1997 ◽  
Vol 36 (49) ◽  
pp. 15294-15302 ◽  
Author(s):  
Fabrice Rappaport ◽  
Jérôme Lavergne
Keyword(s):  
Photosystem Ii ◽  
Proton Transfer ◽  
Charge Recombination

Intermolecular proton transfer in cyclic carbonate synthesis from epoxide and carbon dioxide catalyzed by azaphosphatranes: a DFT mechanistic study

RSC Advances ◽  
2015 ◽  
Vol 5 (16) ◽  
pp. 12382-12386 ◽  
Author(s):  
Zhiqiang Zhang ◽  
Liancai Xu ◽  
Wenkai Feng
Keyword(s):  
Carbon Dioxide ◽  
Proton Transfer ◽  
Dft Calculations ◽  
Cyclic Carbonate ◽  
Solvent Free ◽  
Mechanistic Study ◽  
Cyclic Carbonates ◽  
Intermolecular Proton Transfer

The activity of azaphosphatranes, novel types of non-metal and solvent-free catalysts for the synthesis of cyclic carbonates from epoxides and CO2, is unraveled by DFT calculations.

scholarly journals Electron, proton and hydrogen–atom transfers in photosynthetic water oxidation

2002 ◽  
Vol 357 (1426) ◽  
pp. 1383-1394 ◽  
Author(s):  
Cecilia Tommos
Keyword(s):  
Photosystem Ii ◽  
Proton Transfer ◽  
Water Oxidation ◽  
Oxidation Mechanism ◽  
Bulk Solution ◽  
Hydrogen Atoms ◽  
Redox Active ◽  
Hydrogen Atom Transfers ◽  
Reduce Carbon Dioxide ◽  
Photosynthetic Water Oxidation

When photosynthetic organisms developed so that they could use water as an electron source to reduce carbon dioxide, the stage was set for efficient proliferation. Algae and plants spread globally and provided the foundation for our atmosphere and for O 2 –based chemistry in biological systems. Light–driven water oxidation is catalysed by photosystem II, the active site of which contains a redox–active tyrosine denoted Y Z , a tetramanganese cluster, calcium and chloride. In 1995, Gerald Babcock and co–workers presented the hypothesis that photosynthetic water oxidation occurs as a metallo–radical catalysed process. In this model, the oxidized tyrosine radical is generated by coupled proton/electron transfer and re–reduced by abstracting hydrogen atoms from substrate water or hydroxide–ligated to the manganese cluster. The proposed function of Y Z requires proton transfer from the tyrosine site upon oxidation. The oxidation mechanism of Y Z in an inhibited and O 2 –evolving photosystem II is discussed. Domino–deprotonation from Y Z to the bulk solution is shown to be consistent with a variety of data obtained on metal–depleted samples. Experimental data that suggest that the oxidation of Y Z in O 2 –evolving samples is coupled to proton transfer in a hydrogen–bonding network are described. Finally, a dielectric–dependent model for the proton release that is associated with the catalytic cycle of photosystem II is discussed.

The proton transfer process observed in the structure analysis and DFT calculations of (E)-2-ethoxy-6-[(2-methoxyphenylimino)methyl]phenol

2010 ◽  
Vol 21 (4) ◽  
pp. 681-690 ◽  
Author(s):  
Hande Petek ◽  
Çiğdem Albayrak ◽  
Mustafa Odabaşoğlu ◽  
İsmet Şenel ◽  
Orhan Büyükgüngör
Keyword(s):  
Proton Transfer ◽  
Dft Calculations ◽  
Structure Analysis ◽  
Transfer Process ◽  
Proton Transfer Process
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