scholarly journals Revealing the Intrinsic Peroxidase-Like Catalytic Mechanism of Heterogeneous Single-Atom Co–MoS2

2019 ◽  
Vol 11 (1) ◽  
Author(s):  
Ying Wang ◽  
Kun Qi ◽  
Shansheng Yu ◽  
Guangri Jia ◽  
Zhiliang Cheng ◽  
...  
Keyword(s):  
High Performance ◽  
Catalytic Mechanism ◽  
Single Atom ◽  
Theoretical Studies ◽  
The Novel ◽  
Peroxidase Mimic ◽  
Adsorption Energies ◽  
Experimental And Theoretical Studies ◽  
Transfer Mechanisms ◽  
Different Parts

AbstractThe single-atom nanozyme is a new concept and has tremendous prospects to become a next-generation nanozyme. However, few studies have been carried out to elucidate the intrinsic mechanisms for both the single atoms and the supports in single-atom nanozymes. Herein, the heterogeneous single-atom Co–MoS2 (SA Co–MoS2) is demonstrated to have excellent potential as a high-performance peroxidase mimic. Because of the well-defined structure of SA Co–MoS2, its peroxidase-like mechanism is extensively interpreted through experimental and theoretical studies. Due to the different adsorption energies of substrates on different parts of SA Co–MoS2 in the peroxidase-like reaction, SA Co favors electron transfer mechanisms, while MoS2 relies on Fenton-like reactions. The different catalytic pathways provide an intrinsic understanding of the remarkable performance of SA Co–MoS2. The present study not only develops a new kind of single-atom catalyst (SAC) as an elegant platform for understanding the enzyme-like activities of heterogeneous nanomaterials but also facilitates the novel application of SACs in biocatalysis.

scholarly journals Very Low Energy Collision Induced Vibrational Relaxation: An Overview

1983 ◽  
Vol 2 (3-4) ◽  
pp. 137-166 ◽  
Author(s):  
Stuart A. Rice ◽  
Charles Cerjan
Keyword(s):  
Vibrational Relaxation ◽  
Polyatomic Molecules ◽  
Low Energy ◽  
Quantum Mechanical ◽  
Theoretical Studies ◽  
The Novel ◽  
Energy Collision ◽  
Quantum Mechanical Treatment ◽  
Experimental And Theoretical Studies ◽  
Full Quantum

Recent experimental and theoretical studies of very low energy collision induced vibrational relaxation in diatomic and polyatomic molecules are surveyed. Emphasis is placed on the novel features of the very low energy process; these require a full quantum mechanical treatment of the collision to account for the observations.

Tri-metallic deltahedral Zintl ions: experimental and theoretical studies of the novel dimer [(Sn6Ge2Bi)2]4−

2012 ◽  
Vol 48 (29) ◽  
pp. 3524 ◽  
Author(s):  
Miriam M. Gillett-Kunnath ◽  
Alvaro Muñoz-Castro ◽  
Slavi C. Sevov
Keyword(s):  
Theoretical Studies ◽  
The Novel ◽  
Zintl Ions ◽  
Experimental And Theoretical Studies

scholarly journals Theoretical Studies of the Self Cleavage Pistol Ribozyme Mechanism

2021 ◽  
Author(s):  
Natalia Serrano-Aparicio ◽  
Katarzyna Świderek ◽  
Iñaki Tuñón ◽  
Vicent Moliner ◽  
Joan Bertran
Keyword(s):  
Active Site ◽  
Catalytic Mechanism ◽  
Computational Study ◽  
Md Simulations ◽  
Canonical System ◽  
The Self ◽  
Artificial Enzymes ◽  
Theoretical Studies ◽  
Mechanism Analysis ◽  
Experimental And Theoretical Studies

AbstractRibozymes are huge complex biological catalysts composed of a combination of RNA and proteins. Nevertheless, there is a reduced number of small ribozymes, the self-cleavage ribozymes, that are formed just by RNA and, apparently, they existed in cells of primitive biological systems. Unveiling the details of these “fossils” enzymes can contribute not only to the understanding of the origins of life but also to the development of new simplified artificial enzymes. A computational study of the reactivity of the pistol ribozyme carried out by means of classical MD simulations and QM/MM hybrid calculations is herein presented to clarify its catalytic mechanism. Analysis of the geometries along independent MD simulations with different protonation states of the active site basic species reveals that only the canonical system, with no additional protonation changes, renders reactive conformations. A change in the coordination sphere of the Mg2+ ion has been observed during the simulations, which allows proposing a mechanism to explain the unique mode of action of the pistol ribozyme by comparison with other ribozymes. The present results are at the center of the debate originated from recent experimental and theoretical studies on pistol ribozyme.

The Stabilizing Effect of Pre-Equilibria: A Trifluoromethyl Complex as CF2 Reservoir in Catalytic Olefin Difluorocarbenation

2020 ◽  
Author(s):  
Thomas Louis-Goff ◽  
Huu Vinh Trinh ◽  
Eileen Chen ◽  
Arnold L. Rheingold ◽  
Christian Ehm ◽  
...  
Keyword(s):  
High Selectivity ◽  
Side Reactions ◽  
Theoretical Studies ◽  
Attractive Feature ◽  
Catalyst Recovery ◽  
Wide Range ◽  
Stabilizing Effect ◽  
Experimental And Theoretical Studies

A new, efficient, catalytic difluorocarbenation of olefins to give 1,1-difluorocyclopropanes is presented. The catalyst, an organobismuth complex, uses TMSCF<sub>3</sub> as a stoichiometric difluorocarbene source. We demonstrate both the viability and robustness of this reaction over a wide range of alkenes and alkynes, including electron-poor alkenes, to generate the corresponding 1,1-difluorocyclopropanes and 1,1-difluorocyclopropenes. Ease of catalyst recovery from the reaction mixture is another attractive feature of this method. In depth experimental and theoretical studies showed that the key difluorocarbene-generating step proceeds through a bismuth non-redox synchronous mechanism generating a highly reactive free CF<sub>2</sub> in an endergonic pre-equilibrium. It is the reversibility when generating the difluorocarbene that accounts for the high selectivity, while minimizing CF<sub>2</sub>-recombination side-reactions.

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