scholarly journals Theoretical Study on the Grafting Reaction of Maleimide Containing 2-Hydroxy-Benzophenone Onto Polyethylene

2021 ◽  
Author(s):  
hui Zhang ◽  
Chi Deng ◽  
Xia Du ◽  
Yan Shang ◽  
Hong Zhao ◽  
...  
Keyword(s):  
Density Functional ◽  
Theoretical Study ◽  
Minimum Energy ◽  
Ultra Violet ◽  
Dft Method ◽  
Functional Theory ◽  
Target Molecule ◽  
Grafting Reaction ◽  
Functional Additive ◽  
Reaction Channels

Abstract A theoretical study on the multi-channel hydrogen addition of maleimide containing 2-hydroxy-benzophenone onto polyethylene in Ultra-Violet (UV) radiation cross-linking process was carried out using density functional theory (DFT) method at the B3LYP/6-311+G(d,p) level. The energetic information and the minimum energy path (MEP) are calculated of nine reaction channels. The electrophilic addition reactions at two positions in the target molecule (maleimide containing 2-hydroxy-benzophenone) were investigated, where are on the C atom of C=C groups and on the O atom of C=O groups. Frontier MOs and NBO charge population of the target molecule have been analyzed in detail. As a result, the reaction site of C in C=C group is more active than the site of O in C=O groups. The target molecule can be used as a multi-functional additive candidate. The predicted mechanism may provide a theoretical basis for the real application of XLPE high voltage insulation cables.

scholarly journals Thyroxine: A Theoretical Study of the Vibrational and Electronic Properties

2020 ◽  
Vol 3 (1) ◽  
pp. 31-40
Author(s):  
Ricardo V. K. Rizzon ◽  
Zélia M. da Costa Ludwig ◽  
Ricardo V. K. Rizzon ◽  
Lucas Modesto da Costa ◽  
Valdemir Ludwig
Keyword(s):  
Density Functional Theory ◽  
Electronic Properties ◽  
Density Functional ◽  
Theoretical Study ◽  
Minimum Energy ◽  
Functional Theory ◽  
Structures And Properties ◽  
The Density Functional Theory ◽  
Infra Red ◽  
Simulation Results

Through this work, we systematically studied the structural, vibrational and electronic properties of the fundamental state of the isolated thyroxine(3,5,3’,5-tetraiodothyronine). The minimum energy structures and properties were obtained using the Density Functional Theory (DFT). Our simulation results were compared with experimental results, including infra-red and Raman spectroscopy with an emphasis on the properties of iodine atoms. The UV-vis spectrum calculated in this work is the first result of this model for the thyroxine molecule.

Adsorption behavior of O2 on vacancy-defected graphene with transition-metal dopants: A theoretical study

2018 ◽  
Vol 32 (27) ◽  
pp. 1850304 ◽  
Author(s):  
Qingxiao Zhou ◽  
Yongliang Yong ◽  
Xiangying Su ◽  
Weiwei Ju ◽  
Zhibing Fu ◽  
...  
Keyword(s):  
Transition Metal ◽  
Density Functional ◽  
Theoretical Study ◽  
Dft Method ◽  
Vacancy Defect ◽  
Functional Theory ◽  
Defect Sites ◽  
The Density Functional Theory ◽  
Adsorption Complexes ◽  
Mn Doped

The influence of vacancy and dopants on the adsorption of O2 molecule on graphene was explored by using the density functional theory (DFT) method. The results indicated that the presence of vacancy-defect improved the sensitivity of graphene toward the O2 molecule. Furthermore, the two O atoms of O2 molecule separately formed chemical bonds with C atoms at the defect sites. After introducing the transition-metal (TM) dopants, the O–O bond length of O2 molecule was enlarged by the adsorption on the surface of graphene. Furthermore, the Mn-doped adsorption complexes became magnetic, which was mainly contributed by the O-2p and Mn-3d orbitals.

Density functional theoretical study on the reaction mechanism of SiHF radical with HNCO

2014 ◽  
Vol 13 (07) ◽  
pp. 1450054 ◽  
Author(s):  
Li-Jie Hou ◽  
Bo-Wan Wu ◽  
Yan-Xia Han ◽  
Chao Kong ◽  
Dong-Ping Chen ◽  
...  
Keyword(s):  
Reaction Mechanism ◽  
Density Functional ◽  
Transition State Theory ◽  
Main Product ◽  
Theoretical Study ◽  
State Theory ◽  
Functional Theory ◽  
B3lyp Method ◽  
Reaction Channels ◽  
Thermodynamic And Kinetic Characters

The reaction mechanism of SiHF radical with HNCO has been investigated by the B3LYP method of density functional theory (DFT), while the geometries and harmonic vibration frequencies of reactants, intermediates, transition states and products have been calculated at the B3LYP/6-311++G** level. To obtain more precise energy result, stationary point energies were calculated at the CCSD(T)/6-311++G**//B3LYP/6-311++G** level. In temperature range of 100 K to 1900 K, the statistical thermodynamics and Eyring transition state theory with Winger correction are used to study the thermodynamic and kinetic characters of the channel with low energy barrier at 1.0 Atm. SiHF + HNCO → IM 8 → TS 8 → SiFNHCHO ( P 3) was the main channel with low potential energy in the singlet state, SiFNHCHO was the main product. The analyses for the combining interaction between SiHF radical and HNCO with the atom-in-molecules (AIM) theory have been performed. There are three reaction channels in the triplet.

scholarly journals Theoretical study on the Diels-Alder reaction of bromo-substituted 2H-pyrane-2-ones and some substituent vinyls

2015 ◽  
Vol 80 (9) ◽  
pp. 1139-1148
Author(s):  
Mina Haghdadi ◽  
Hamed Amani ◽  
Nasim Nab
Keyword(s):  
Density Functional ◽  
Theoretical Study ◽  
Alder Reaction ◽  
Diels Alder ◽  
Free Energies ◽  
Functional Theory ◽  
Concerted Mechanism ◽  
Diels Alder Reaction ◽  
Reaction Channels ◽  
Orbital Analysis

A DFT study of the reactivity, regio- and stereoselectivity of Diels-Alder reaction between 3-bromo, 5-bromo, and 3,5-dibromo-2(H)-pyran-2-ones and some weakly activated and unactivated alkenes has been carried out using density functional theory (DFT). Four possible reaction channels, which are related to the formation of meta- and para- and endo- and exo-cycloadducts have been explored and characterized. The energy and natural bond orbital analysis shows that the meta-regioselectivity on the exo pathway is preferred and follows an asynchronous concerted mechanism with a polar nature in all Diels-Alder cycloadditions. Moreover, the activation free energies of Diels-Alder cycloadditions of 3,5-dibromo-2(H)-pyran-2one are lower than 3- bromo-2(H)-pyran-2one and 5-bromo-2(H)-pyran-2one, which are in line with experimental observation. DFT-based reactivity indices clearly predict the regiochemistry of the isolated cycloadducts.

Theoretical Study on the Hydroboration of α,β-Unsaturated Carbonyl Compounds Catalyzed by Metal-Free Complex and Subsequent C−C Coupling with Acetonitrile

2021 ◽  
Author(s):  
Ling Zhu ◽  
Lin Zhang ◽  
Zuoyin Yang ◽  
Min Pu ◽  
Ming Lei
Keyword(s):  
Density Functional Theory ◽  
Reaction Mechanism ◽  
Carbonyl Compounds ◽  
Density Functional ◽  
Theoretical Study ◽  
Dft Method ◽  
Functional Theory ◽  
Metal Free

Herein density functional theory (DFT) method was employed to explore the reaction mechanism of selective hydroboration of α,β-unsaturated carbonyl compounds catalyzed by the metal-free complex, 1,3,2-diazaphospholene (DAP). The whole reaction...

Understanding the molecular mechanism of the stereoselective conversion of N-trialkylsilyloxy nitronates into bicyclic isoxazoline derivatives

2021 ◽  
Author(s):  
Agnieszka Kącka-Zych ◽  
Radomir Jasinski
Keyword(s):  
Density Functional Theory ◽  
Molecular Mechanism ◽  
Electron Density ◽  
Density Functional ◽  
Dft Method ◽  
Functional Theory ◽  
Molecular Electron ◽  
Molecular Electron Density Theory

Conversion of N-trialkylsilyloxy nitronates into bicyclic isoxazoline derivatives has been explored using Density Functional Theory (DFT) method within the context of the Molecular Electron Density Theory (MEDT) at the B97XD(PCM)/6-311G(d,p)...

scholarly journals Boron-Decorated Pillared Graphene as the Basic Element for Supercapacitors: An Ab Initio Study

2021 ◽  
Vol 11 (8) ◽  
pp. 3496
Author(s):  
Dmitry A. Kolosov ◽  
Olga E. Glukhova
Keyword(s):  
Density Functional ◽  
Dft Method ◽  
Heat Of Formation ◽  
Basic Element ◽  
Supercapacitor Electrode ◽  
Functional Theory ◽  
Icosahedral Clusters ◽  
New Material ◽  
Principle Density Functional Theory ◽  
Specific Quantum

In this work, using the first-principle density functional theory (DFT) method, we study the properties of a new material based on pillared graphene and the icosahedral clusters of boron B12 as a supercapacitor electrode material. The new composite material demonstrates a high specific quantum capacitance, specific charge density, and a negative value of heat of formation, which indicates its efficiency. It is shown that the density of electronic states increases during the addition of clusters, which predictably leads to an increase in the electrode conductivity. We predict that the use of a composite based on pillared graphene and boron will increase the efficiency of existing supercapacitors.

scholarly journals Theoretical Study of Zirconium Isomorphous Substitution into Zeolite Frameworks

Molecules ◽  
2019 ◽  
Vol 24 (24) ◽  
pp. 4466
Author(s):  
Duichun Li ◽  
Bin Xing ◽  
Baojun Wang ◽  
Ruifeng Li
Keyword(s):  
Acid Site ◽  
Density Functional ◽  
Theoretical Study ◽  
Atomic Radius ◽  
Acid Sites ◽  
Isomorphous Substitution ◽  
Dispersion Correction ◽  
Brønsted Acidity ◽  
Functional Theory ◽  
Brönsted Acidity

Systematic periodic density functional theory computations including dispersion correction (DFT-D) were carried out to determine the preferred location site of Zr atoms in sodalite (SOD) and CHA-type topology frameworks, including alumino-phosphate-34 (AlPO-34) and silico-alumino-phosphate-34 (SAPO-34), and to determine the relative stability and Brönsted acidity of Zr-substituted forms of SOD, AlPO-34, and SAPO-34. Mono and multiple Zr atom substitutions were considered. The Zr substitution causes obvious structural distortion because of the larger atomic radius of Zr than that of Si, however, Zr-substituted forms of zeolites are found to be more stable than pristine zeolites. Our results demonstrate that in the most stable configurations, the preferred favorable substitutions of Zr in substituted SOD have Zr located at the neighboring sites of the Al-substituted site. However, in the AlPO-34 and SAPO-34 frameworks, the Zr atoms are more easily distributed in a dispersed form, rather than being centralized. Brönsted acidity of substituted zeolites strongly depends on Zr content. For SOD, substitution of Zr atoms reduces Brönsted acidity. However, for Zr-substituted forms of AlPO-34 and SAPO-34, Brönsted acidity of the Zr-O(H)-Al acid sites are, at first, reduced and, then, the presence of Zr atoms substantially increased Brönsted acidity of the Zr-O(H)-Al acid site. The results in the SAPO-34-Zr indicate that more Zr atoms substantially increase Brönsted acidity of the Si-O(H)-Al acid site. It is suggested that substituted heteroatoms play an important role in regulating and controlling structural stability and Brönsted acidity of zeolites.

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