Key roles of electron cloud density and configuration in the adsorption of sulfonamide antibiotics on carbonaceous materials: Molecular dynamics and quantum chemical investigations

2021 ◽  
Vol 536 ◽  
pp. 147757 ◽  
Author(s):  
Quan Chen ◽  
Xi Wang ◽  
Peng Yi ◽  
Peng Zhang ◽  
Lijuan Zhang ◽  
...  
Keyword(s):  
Molecular Dynamics ◽  
Quantum Chemical ◽  
Electron Cloud ◽  
Carbonaceous Materials ◽  
Sulfonamide Antibiotics ◽  
Cloud Density

Prediction of Alkanolamine pKa Values by Combined Molecular Dynamics Free Energy Simulations and ab initio Calculations

2019 ◽  
Author(s):  
Javad Noroozi ◽  
William Smith
Keyword(s):  
Molecular Dynamics ◽  
Free Energy ◽  
Ab Initio Calculations ◽  
Gas Phase ◽  
Quantum Chemical ◽  
Phase Reaction ◽  
Pka Values ◽  
Gas Phase Reaction ◽  
Reaction Free Energy ◽  
Energy Simulations

We use molecular dynamics free energy simulations in conjunction with quantum chemical calculations of gas phase reaction free energy to predict alkanolamines pka values. <br>

Progress in preparation and characterization of silylene iron, cobalt and nickel complexes

2021 ◽  
Author(s):  
Wenjing Yang ◽  
Yanhong Dong ◽  
Hongjian Sun ◽  
Xiaoyan Li
Keyword(s):  
Nickel Complexes ◽  
Electron Cloud ◽  
Synthesis And Characterization ◽  
Iron Cobalt ◽  
Cloud Density ◽  
Cobalt And Nickel

The synthesis and characterization of Fe, Co and Ni complexes supported by silylene ligands in recent ten years are summarized. Due to the decrease of electron cloud density on Si...

Investigation of the interfacial behavior of organics on sulfide semiconductor surfaces by quantum chemical calculations and molecular dynamics simulations

2021 ◽  
Author(s):  
Haiding Zhu ◽  
Xuefeng Ren ◽  
Shengxiang Yan ◽  
Xingyou Liang ◽  
Liguo Gao ◽  
...  
Keyword(s):  
Molecular Dynamics ◽  
Molecular Dynamics Simulations ◽  
Quantum Chemical Calculations ◽  
Organic Pollutants ◽  
Quantum Chemical ◽  
Semiconductor Surfaces ◽  
Interfacial Behavior ◽  
The World ◽  
Dynamics Simulations

The presence of organic pollutants in the world is harmful to our existence and the environment.

Computational Study for Molecular Properties of Some of the Isolated Chemicals from Leaves Extract of Guiera Senegalensis as Aluminium Corrosion Inhibitor

2021 ◽  
Vol 13 (1) ◽  
Author(s):  
A. M. Ayuba ◽  
◽  
M. Abubakar ◽  
Keyword(s):  
Molecular Dynamics ◽  
Quantum Chemical ◽  
Energy Gap ◽  
Computational Study ◽  
Physical Adsorption ◽  
Chemical Constituents ◽  
Molecular Size ◽  
Structural Features ◽  
Inhibitor Molecule ◽  
Fukui Indices

The present work describes the computational methods for the corrosion inhibition of aluminium using three selected chemical constituents (5-methyldihydroflavasperone, 5-methylflavasperone and methoxylated naphthyl butanone) reportedly obtained from the leaves extract of Guirea senegalensis. Quantum chemical calculations including EHOMO, ELUMO, energy gap (ΔE), electronegativity (χ), global hardness (η) and fraction of electrons transfer from the inhibitor molecule to the aluminium surface (ΔN) were calculated. The local reactive sites through Fukui indices which explain the effect of structural features of these components in relation to electrophilic and nucleophilic point of attack were evaluated. The similarities in quantum chemical parameters for the compounds obtained revealed that the adsorption strengths of the molecules will be mostly determined by molecular size rather than electronic structure parameters. Fukui indices showed that the point of interaction of inhibitor molecule with the Al(l10) surface were through aromatic carbon atom rich in pi-electrons and oxygen atom of the alkanone functional group in the inhibitor molecules. Molecular dynamics simulations describing the adsorption behavior of the inhibitor molecule on Al(110) surface through Forcite quench molecular dynamics were carried out. The compounds were found to all obey the mechanism of physical adsorption because of their relatively low adsorption energies.

Simulation of Thermal Stability and Friction: A Lubricant Confined Between Monolayers of Wear Inhibitors on Iron Oxide

1998 ◽  
Vol 543 ◽  
Author(s):  
T. Çağin ◽  
Y. Zhou ◽  
E. S. Yamaguchi ◽  
R. Frazier ◽  
A. Ho ◽  
...  
Keyword(s):  
Molecular Dynamics ◽  
Thermal Stability ◽  
Quantum Chemical ◽  
Md Simulations ◽  
Atomic Level ◽  
The Self ◽  
Self Assembled Monolayer ◽  
Thermal Stabilities ◽  
Frictional Forces ◽  
Thermal Stability Of

AbstractTo understand antiwear phenomena in motor engines at the atomic level and provide evidence inselecting future ashless wear inhibitors, we studied the thermal stability of the self-assembled monolayer(SAM) model for dithiophosphate (DTP) and dithiocarbamate (DTC) molecules on the iron oxidesurface using molecular dynamics. The interactions for DTP, DTC and Fe2O3 are evaluated based on aforce field derived from fitting to ab initio quantum chemical calculations of dimethyl DTP (and DTC)and Fe(OH)2(H2O)2-DTP (DTC) clusters. MD simulations at constant-NPT are conducted to assesrelative thermal stabilities of the DTP and DTC with different pendant groups (n-propyl, i-propyl, npentyl.and i-pentyl). To investigate frictional process, we employ a steady state MD method, in whichone of the Fe2O3 slabs maintained at a constant linear velocity. We obtain the time averaged normaland frictional forces from the interatomic forces. Then, we calculated the friction coefficient at theinterface between SAMs of DTP and the confined lubricant, hexadecane, to assess the shear stability ofDTPs with different pendant groups.

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