Electron transfers in graphitized HZSM-5 zeolite

2020 ◽  
Author(s):  
Alain Moissette ◽  
Isabelle Gener-Batonneau ◽  
Matthieu Hureau ◽  
Ludovic Pinard ◽  
Hervé Vezin ◽  
...  
Keyword(s):  
Guest Molecule ◽  
Zeolite P ◽  
Electron Transfers

In the present work, we report the electron transfers occurring after ionization of the guest molecule of t-stilbene incorporated in graphitized HZSM-5 zeolite and we compare these results with the...

Electron transfers in a TiO2-containing MOR zeolite: synthesis of the nanoassemblies and application using a probe chromophore molecule

2014 ◽  
Vol 16 (26) ◽  
pp. 13145-13155 ◽  
Author(s):  
A. Legrand ◽  
A. Moissette ◽  
M. Hureau ◽  
S. Casale ◽  
P. Massiani ◽  
...  
Keyword(s):  
Conduction Band ◽  
Guest Molecule ◽  
Zeolite Synthesis ◽  
Conductive Material ◽  
Electron Transfers

Ionization of a guest molecule occluded in a TiO2-containing zeolite and electron transfers to the conduction band of the conductive material placed nearby.

Conformational Stability, FMO, NMR, MEP and NBO Analysis of 2,5-Di-methyl-2,5-bis(methylthio)-1,4-dithiane and Dimethoxy compounds by DFT Approach

2021 ◽  
Vol 17 ◽  
Author(s):  
Nasrin Masnabadi
Keyword(s):  
Computational Methods ◽  
Electrostatic Potential ◽  
Conformational Stability ◽  
Nbo Analysis ◽  
Dft Methods ◽  
Geometrical Properties ◽  
Stereoelectronic Effect ◽  
Nmr Parameters ◽  
Electron Transfers ◽  
Stability Energy

Abstract: Conformational behaviors of 2,5-dimethoxy-2,5-dimethyl-1,4-dithiane (compound 1) and 2,5-dimethyl-2,5-bis (methylthio)-1,4-dithiane (compound 2) investigated by computational methods including B3LYP/6-311+G** and M06-2X/6-311+G** levels of theory and NBO analysis. The stereoelectronic effect of axial, axial (ax, ax) and equatorial, equa-torial (eq, eq) conformations were studied using NBO analysis. Using NBO analysis, the values of the stereoelectronic effects were calculated through the energy of stability associated with the electron transfers of compounds 1 and 2. The results showed that the eq, eq conformations of the studied compounds were more stable than their corresponding ax, ax conformations, and LP2X→σS1-C2 and LP2S→σ*C2-X electron transfers play important roles in the conformational be-havior of the studied compounds. The main purpose of the present work was to study the effects of stereoelectronic inter-actions and steric on the conformational superiority of the di-methoxy (compound 1) and di-thiomethyl compounds (com-pound 2). Thus, the values of resonance stability energy, non-diagonal elements, and orbital populations were investigated. Also, active electrophilic and nucleophilic centers were identified using fronting orbitals analysis obtained by DFT methods. The electrostatic potential maps of the title compounds were investigated at the B3LYP/6-311+G* level of theory. All of the NMR parameters and geometrical properties of both compounds were determined in this study.

scholarly journals Helarchaeota and co-occurring sulfate-reducing bacteria in subseafloor sediments from the Costa Rica Margin

2021 ◽  
Vol 1 (1) ◽  
Author(s):  
Rui Zhao ◽  
Jennifer F. Biddle
Keyword(s):  
Costa Rica ◽  
Metabolic Pathways ◽  
Phylogenetic Analyses ◽  
Sulfate Reducing Bacteria ◽  
Sulfate Reducing ◽  
Hydrocarbon Emission ◽  
Costa Rica Margin ◽  
Reducing Bacteria ◽  
Electron Transfers ◽  
Deep Sediments

AbstractDeep sediments host many archaeal lineages, including the Asgard superphylum which contains lineages predicted to require syntrophic partnerships. Our knowledge about sedimentary archaeal diversity and their metabolic pathways and syntrophic partners is still very limited. We present here new genomes of Helarchaeota and the co-occurring sulfate-reducing bacteria (SRB) recovered from organic-rich sediments off Costa Rica Margin. Phylogenetic analyses revealed three new metagenome-assembled genomes (MAGs) affiliating with Helarchaeota, each of which has three variants of the methyl-CoM reductase-like (MCR-like) complex that may enable them to oxidize short-chain alkanes anaerobically. These Helarchaeota have no multi-heme cytochromes but have Group 3b and Group 3c [NiFe] hydrogenases, and formate dehydrogenase, and therefore have the capacity to transfer the reducing equivalents (in the forms of hydrogen and formate) generated from alkane oxidation to external partners. We also recovered five MAGs of SRB affiliated with the class of Desulfobacteria, two of which showed relative abundances (represented by genome coverages) positively correlated with those of the three Helarchaeota. Genome analysis suggested that these SRB bacteria have the capacity of H2 and formate utilization and could facilitate electron transfers from other organisms by means of these reduced substances. Their co-occurrence and metabolic features suggest that Helarchaeota may metabolize synergistically with some SRB, and together exert an important influence on the carbon cycle by mitigating the hydrocarbon emission from sediments to the overlying ocean.

Gating control effect facilitates excellent gas selectivity in a novel Na-SSZ-27 zeolite

2021 ◽  
Vol 57 (34) ◽  
pp. 4170-4173
Author(s):  
Chao Zhao ◽  
Jiamin Yuan ◽  
Xiaomin Tang ◽  
Wei Chen ◽  
Xianfeng Yi ◽  
...  
Keyword(s):  
Control Effect ◽  
Crucial Effect ◽  
Gas Selectivity ◽  
Zeolite P

A novel Na-SSZ-27 zeolite was demonstrated to possess excellent H2/CO2 diffusion selectivity due to the crucial effect of the “gating control” of the 8-ring windows.

scholarly journals Hydrogen Inter-Cage Hopping and Cage Occupancies inside Hydrogen Hydrate: Molecular-Dynamics Analysis

2020 ◽  
Vol 11 (1) ◽  
pp. 282
Author(s):  
Yogeshwaran Krishnan ◽  
Mohammad Reza Ghaani ◽  
Arnaud Desmedt ◽  
Niall J. English
Keyword(s):  
Molecular Dynamics ◽  
Energy Barrier ◽  
Guest Molecule ◽  
Arrhenius Equation ◽  
Dynamics Simulation ◽  
Type Ii ◽  
Large Cage ◽  
Guest Molecules ◽  
Simulation Time ◽  
Average Occupancy

The inter-cage hopping in a type II clathrate hydrate with different numbers of H2 and D2 molecules, from 1 to 4 molecules per large cage, was studied using a classical molecular dynamics simulation at temperatures of 80 to 240 K. We present the results for the diffusion of these guest molecules (H2 or D2) at all of the different occupations and temperatures, and we also calculated the activation energy as the energy barrier for the diffusion using the Arrhenius equation. The average occupancy number over the simulation time showed that the structures with double and triple large-cage H2 occupancy appeared to be the most stable, while the small cages remained with only one guest molecule. A Markov model was also calculated based on the number of transitions between the different cage types.

scholarly journals Ni–rGO–zeolite nanocomposite: An efficient heterogeneous catalyst for one–pot synthesis of triazoles in water

2021 ◽  
Author(s):  
Prasun Choudhury ◽  
Shreyasi Chattopadhyay ◽  
Goutam De ◽  
Basudeb Basu
Keyword(s):  
Heterogeneous Catalyst ◽  
Y Zeolite ◽  
One Pot ◽  
Important Group ◽  
One Pot Synthesis ◽  
Nanocomposite Catalyst ◽  
Zeolite P ◽  
Efficient Heterogeneous Catalyst

An important group of pharmaceutical material, 1,2,3-triazoles has been synthesised using a Ni-based nanocomposite catalyst (Ni–rGO–zeolite) through azide alkyne cycloaddition (NiAAC). First, GO-zeolite hybrid was prepared through protonation of Na-Y-zeolite...

scholarly journals Guest Molecule-Responsive Functional Calcium Phosphonate Frameworks for Tuned Proton Conductivity

2014 ◽  
Vol 136 (15) ◽  
pp. 5731-5739 ◽  
Author(s):  
Montse Bazaga-García ◽  
Rosario M. P. Colodrero ◽  
Maria Papadaki ◽  
Piotr Garczarek ◽  
Jerzy Zoń ◽  
...  
Keyword(s):  
Proton Conductivity ◽  
Guest Molecule

Correction to Hydrogen-Bond Relays in Concerted Proton–Electron Transfers

2013 ◽  
Vol 46 (8) ◽  
pp. 1910-1910
Author(s):  
Julien Bonin ◽  
Cyrille Costentin ◽  
Marc Robert ◽  
Jean-Michel Savéant ◽  
Cédric Tard
Keyword(s):  
Hydrogen Bond ◽  
Electron Transfers
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