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 ◽  
...  
2018 ◽  
Vol 8 (22) ◽  
pp. 5735-5739 ◽  
Author(s):  
Xiuli Yan ◽  
Hongyu Ge ◽  
Xinzheng Yang

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.


2019 ◽  
Vol 55 (84) ◽  
pp. 12635-12638 ◽  
Author(s):  
Carlos Bornes ◽  
Mariana Sardo ◽  
Zhi Lin ◽  
Jeffrey Amelse ◽  
Auguste Fernandes ◽  
...  

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.


2020 ◽  
Vol 22 (28) ◽  
pp. 15831-15841
Author(s):  
Naoki Sakashita ◽  
Hiroshi Ishikita ◽  
Keisuke Saito

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.


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

Biochemistry ◽  
1997 ◽  
Vol 36 (49) ◽  
pp. 15294-15302 ◽  
Author(s):  
Fabrice Rappaport ◽  
Jérôme Lavergne

RSC Advances ◽  
2015 ◽  
Vol 5 (16) ◽  
pp. 12382-12386 ◽  
Author(s):  
Zhiqiang Zhang ◽  
Liancai Xu ◽  
Wenkai Feng

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.


2002 ◽  
Vol 357 (1426) ◽  
pp. 1383-1394 ◽  
Author(s):  
Cecilia Tommos

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.


2010 ◽  
Vol 21 (4) ◽  
pp. 681-690 ◽  
Author(s):  
Hande Petek ◽  
Çiğdem Albayrak ◽  
Mustafa Odabaşoğlu ◽  
İsmet Şenel ◽  
Orhan Büyükgüngör

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