scholarly journals Zinc-Doped Boron Phosphide Nanocluster as Efficient Sensor for SO2

2020 ◽  
Vol 2020 ◽  
pp. 1-12 ◽  
Author(s):  
Shahid Hussain ◽  
Shahzad Ali Shahid Chatha ◽  
Abdullah Ijaz Hussain ◽  
Riaz Hussain ◽  
Muhammad Yasir Mehboob ◽  
...  
Keyword(s):  
Density Functional Theory ◽  
Density Functional ◽  
Frontier Molecular Orbital ◽  
Functional Theory ◽  
Global Indices ◽  
Boron Phosphide ◽  
Adsorption Energies ◽  
Molecular Orbital Analysis ◽  
Orbital Analysis ◽  
Optimized Geometries

Adsorption of SO2 on pure B12P12 and Zn-doped B12P12 is investigated through density functional theory methods. Zn adsorption on BP delivers four optimized geometries: B-Top, P-top, b64, and ring-enlarged geometry with adsorption energies of −57.12 kJ/mol, −14.50 kJ/mol, −22.94 kJ/mol, and −14.83 kJ/mol, respectively. The adsorption energy of SO2 on pristine boron phosphide is −14.92 kJ/mol. Interaction of SO2 with Zn-doped boron phosphide gives four different geometries with adsorption energies of −69.76 kJ/mol, −9.82 kJ/mol, −104.92 kJ/mol, and −41.87 kJ/mol. Geometric parameters such as dipole moment, QNBO, frontier molecular orbital analysis, PDOS, and global indices of reactivity are performed to visualize the changes in electronic properties of B12P12 after Zn and SO2 adsorption.

scholarly journals Molecular Modeling of Interactions between N-(Carboxymethyl)-N-tetradecylglycine and Fluorapatite

Minerals ◽  
2019 ◽  
Vol 9 (5) ◽  
pp. 278 ◽  
Author(s):  
Nan Nan ◽  
Yimin Zhu ◽  
Yuexin Han ◽  
Jie Liu
Keyword(s):  
Density Functional ◽  
Density Functional Theory Calculation ◽  
Service Condition ◽  
Frontier Molecular Orbital ◽  
Adsorption Ability ◽  
Functional Theory ◽  
Molecular Orbital Analysis ◽  
Theory Calculation ◽  
Orbital Analysis ◽  
Flotation Collector

In this study, a flotation collector N-(carboxymethyl)-N-tetradecylglycine (NCNT) was introduced for the purpose of energy-saving, and its adsorption ability on a fluorapatite (001) surface was investigated by density functional theory calculation. The results of frontier molecular orbital analysis of NCNT and adsorption energy between NCNT and fluorapatite (FAp) showed that NCNT possessed better activity and stronger interactions in the reagent–FAp system than oleic acid (OA). A simulation model revealed that the adsorption positions of NCNT on the fluorapatite surface are calcium atoms, at which NCNT chemisorbed on (001) fluorapatite surface via a bidentate geometry involving the formation of two Ca–O bonds. Flotation experiments verified that NCNT had a good recovery of 92.27% on FAp at pH 3.5, which was slightly lower than OA. Moreover, NCNT was used at 16 °C, which was much lower than the OA’s service condition (25 °C).

Understanding the singlet–triplet energy splittings in transition metal-capped carbon chains

2020 ◽  
Vol 22 (5) ◽  
pp. 2858-2869
Author(s):  
Peizhi Li ◽  
Zhipeng Yang ◽  
Zhong Zhang ◽  
Liang Pu ◽  
R. Bruce King
Keyword(s):  
Density Functional Theory ◽  
Transition Metal ◽  
Molecular Orbital ◽  
Density Functional ◽  
General Feature ◽  
Triplet Energy ◽  
Functional Theory ◽  
Carbon Chains ◽  
Molecular Orbital Analysis ◽  
Orbital Analysis

Density functional theory and molecular orbital analysis suggest that the odd–even alternation of singlet–triplet energy separations is a general feature of transition metal-capped carbon chains, determined primarily by the carbon chains.

scholarly journals Mechanistic investigations on Pinnick oxidation: a density functional theory study

2020 ◽  
Vol 7 (2) ◽  
pp. 191568 ◽  
Author(s):  
Aqeel A. Hussein ◽  
Azzam A. M. Al-Hadedi ◽  
Alaa J. Mahrath ◽  
Gamal A. I. Moustafa ◽  
Faisal A. Almalki ◽  
...  
Keyword(s):  
Density Functional Theory ◽  
Density Functional ◽  
Interaction Analysis ◽  
Computational Study ◽  
Aldehyde Group ◽  
Frontier Molecular Orbital ◽  
Intrinsic Reaction Coordinate ◽  
Reaction Step ◽  
Functional Theory ◽  
Molecular Orbital Analysis

A computational study on Pinnick oxidation of aldehydes into carboxylic acids using density functional theory (DFT) calculations has been evaluated with the (SMD)-M06-2X/aug-pVDZ level of theory, leading to an important understanding of the reaction mechanism that agrees with the experimental observations and explaining the substantial role of acid in driving the reaction. The DFT results elucidated that the first reaction step (FRS) proceeds in a manner where chlorous acid reacts with the aldehyde group through a distorted six-membered ring transition state to give a hydroxyallyl chlorite intermediate that undergoes a pericyclic fragmentation to release the carboxylic acid as a second reaction step (SRS). 1 H NMR experiments and simulations showed that hydrogen bonding between carbonyl and t -butanol is unlikely to occur. Additionally, it was found that the FRS is a rate-determining and thermoneutral step, whereas SRS is highly exergonic with a low energetic barrier due to the Cl(III) → Cl(II) reduction. Frontier molecular orbital analysis, intrinsic reaction coordinate, molecular dynamics and distortion/interaction analysis further supported the proposed mechanism.

A Density Functional Theory Study on the Ring-Opening Polymerization of D-Lactide Catalyzed by a Bifunctional-Thiourea Catalyst

2009 ◽  
Vol 62 (2) ◽  
pp. 157 ◽  
Author(s):  
Rong-Xiu Zhu ◽  
Ruo-Xi Wang ◽  
Dong-Ju Zhang ◽  
Cheng-Bu Liu
Keyword(s):  
Density Functional Theory ◽  
Ring Opening ◽  
Density Functional ◽  
Population Analysis ◽  
Density Functional Theory Calculations ◽  
Ring Opening Polymerization ◽  
Acyl Transfer ◽  
Frontier Molecular Orbital ◽  
Functional Theory ◽  
Elimination Pathway

The thiourea-catalyzed methanolysis of d-lactide, a model system for the initiation and propagation of the organocatalyzed ring-opening polymerization (ROP) of lactide, has been studied by performing density functional theory calculations. Both the catalyzed and uncatalyzed reactions are explored along two possible pathways: one involves the stepwise addition–elimination pathway and the other is related to the concerted pathway. It is found that the reaction without the presence of the catalyst is difficult because the barrier involved is as high as 176 kJ mol–1. With the aid of a thiourea catalyst, the barrier is reduced to 88 kJ mol–1 with a preference for the stepwise addition–elimination mechanism over the concerted one. The role of the catalyst has been rationalized by analyzing the frontier molecular orbital interactions between the catalyst and substrates and by performing natural population analysis. Finally, another mechanism involving acyl transfer is discussed for the thiourea-catalyzed ROP.

CH2O Adsorption on M (M = Li, Mg and Al) Atom Deposited ZnO Nano-Cage: DFT Study

2018 ◽  
Vol 786 ◽  
pp. 384-392 ◽  
Author(s):  
Hussein Y. Ammar
Keyword(s):  
Density Functional Theory ◽  
Bond Length ◽  
Density Functional ◽  
Functional Theory ◽  
The Density Functional Theory ◽  
Structural And Electronic Properties ◽  
Formaldehyde Molecule ◽  
Electronic Configurations ◽  
Adsorption Energies ◽  
Homo Lumo

The structural and electronic properties of Li, Mg and Al deposited ZnO nanocages and their effects on the adsorption of formaldehyde molecule have been investigated using the density functional theory (DFT) computations. To understand the behavior of the adsorbed CH2O molecule on the ZnO nanocage, results of DFT calculations of the M-deposited nanocages (M=Li, Mg and Al), as well as complex systems consisting of the adsorbed CH2O molecule on M-deposited ZnO nanocage were reported. The results presented include adsorption energies, bond lengths, electronic configurations, density of states and molecular orbitals. It was found that, the most energetically stable adsorption configurations of CH2O molecule on the bare ZnO leads to 12% dilation in C=O bond length of CH2O and 14% decrease in HOMO-LUMO gap of ZnO cluster. The most energetically stable adsorption configurations of CH2O molecule on Li, Mg and Al-deposited ZnO lead to 4%, 4% and 11% dilation in C=O bond length of CH2O and-0.66, -45 and , +66% change in HOMO-LUMO gap of ZnO nanocages, respectively. The interaction between CH2O with bare ZnO and M-deposited ZnO nanocages is attributed to charge transfer mechanism. These results may be meaningful for CH2O degradation and detection.

scholarly journals Stability and magnetic properties of isomorphous substituted Si7-xMnx+

2018 ◽  
Vol 56 (1) ◽  
pp. 64
Author(s):  
Nguyen Thanh Tung ◽  
Nguyen Thi Mai ◽  
Ngo Tuan Cuong
Keyword(s):  
Density Functional Theory ◽  
Magnetic Properties ◽  
Magnetic Moment ◽  
Density Functional ◽  
Basis Set ◽  
Pentagonal Bipyramid ◽  
Functional Theory ◽  
Electronic Configurations ◽  
Method Of Density Functional ◽  
Optimized Geometries

The optimized geometries, stability, and magnetic properties of cationic clusters Si7+, Si6Mn+, and Si5Mn2+ have been determined by the method of density functional theory using the B3P86/6-311+G(d) functional/basis set. Their electronic configurations have been analyzed to understand the influence of substituting Si atoms by Mn atoms on the structural and magnetic aspects of Si7+. It is shown that the manganese dopant does not alter the structure of the silicon host but significantly changes its stability and magnetism. In particular, while the magnetic moment of Si7+ is 1 mB, Si5Mn2+ exhibits a strong magnetic moment of 9 mB and that of Si6Mn+ takes a relatively high value of 4 mB. Among studied clusters, the pentagonal bipyramid Si5Mn2+ is assigned as the most stable one.

Nitrogen induced phosphorene formation on the boron phosphide (111) surface: a density functional theory study

RSC Advances ◽  
2016 ◽  
Vol 6 (110) ◽  
pp. 108621-108626 ◽  
Author(s):  
J. Guerrero-Sánchez ◽  
M. Lopez-Fuentes ◽  
F. Sánchez-Ochoa ◽  
Noboru Takeuchi ◽  
Gregorio H. Cocoletzi
Keyword(s):  
Density Functional Theory ◽  
Dft Calculations ◽  
Density Functional ◽  
Density Functional Theory Study ◽  
Functional Theory ◽  
Boron Phosphide

Nitrogen induced phosphorene formation on top of the BP (111) surface is investigated using periodic density functional theory (DFT) calculations.

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