Silylene Reaction with Acetylene: Elucidating the Mechanism by Theoretical Identification of a New Intermediate

2011 ◽  
Vol 36 (4) ◽  
pp. 323-328
Author(s):  
Yiling Bei ◽  
Qingyang Liu
Keyword(s):  
Kinetic Analysis ◽  
Density Function ◽  
Room Temperature ◽  
Function Theory ◽  
Reaction Pathway ◽  
Dft Method ◽  
Density Function Theory

The reaction of silylene with acetylene was observed by the density function theory (DFT) method at the 6 - 311 g (d,p) level. A new reaction pathway has been identified involving the tetra-conjugated: SiH2CH==CHH2Si:. Thermodynamic and kinetic analysis confirms the reaction to be spontaneous at room temperature. The new intermediate proposed in this work offers a resolution of the conundrum of the silylene/acetylene reaction.

Analysis of Ring-Opening Reaction between Bisphenol A and Epichlorohydrin by the Method of Quantum Chemical Calculating

2011 ◽  
Vol 221 ◽  
pp. 180-183 ◽  
Author(s):  
Jian Li ◽  
Xun Zhang Yu ◽  
Kai Zhang
Keyword(s):  
Bisphenol A ◽  
Density Function ◽  
Quantum Chemical ◽  
Ring Opening ◽  
Function Theory ◽  
Dft Method ◽  
Density Function Theory ◽  
Ring Opening Reaction ◽  
Calculation Results ◽  
Opening Process

The ring-opening reaction between bisphenol A and epichlorohydrin was calculated by Gaussian03. The Density Function Theory (DFT) method were employed to study the geometry structures of bisphenol A and epichlorohydrin and the product was obtained on the base of B3LYP/6-31G+ model in this paper. The transitional states (Ts1, Ts2) during the ring-opening process were found by TS method and the energy changing of the system was proved by IRC calculation. Results showed that the energy reduced by 64.37726kJ/mol during the ring-opening process. The product was confirmed to be thermodynamically stable.

Effect of Al, Ti and Cr Doping on Vanadium Dioxide (VO2) Analyzed by Density Function Theory (DFT) Method

2020 ◽  
Vol 20 (3) ◽  
pp. 1651-1659 ◽  
Author(s):  
Hongmei Zhu ◽  
Zhengjie Zhang ◽  
Xuchuan Jiang
Keyword(s):  
Electronic Structure ◽  
Band Gap ◽  
Density Function ◽  
Vanadium Dioxide ◽  
Function Theory ◽  
Dft Method ◽  
Density Function Theory ◽  
Atomic Scale ◽  
Elemental Doping ◽  
Cr Doping

Density function theory (DFT) method was developed and applied for fundamentally understanding the doping effect of various metals (Al, Ti and Cr) on vanadium dioxide (VO2). The substitution doping of Al, Ti and Cr in VO2 could lead to significant changes in electronic structure, band gap and optical property. Different from physical experiments, the DFT method could be utilized for fundamental understandings at an atomic scale. It was found via DFT calculations that: (i) Al doping caused a slightly distorted octahedron in monoclinic VO2(M), and narrowed the band gap of VO2(M) due to the upward shift of the valence band (VB), while Cr doping narrowed the band gap because of the downward shift of the conduction band (CB); (ii) Ti doping slightly widened the band gap of VO2(M); and (iii) the optical reflectivity of VO2(M) decreased after substitution doping low-valent metals (e.g., Al). This study will be beneficial for designing and controlling elemental doping to obtain metal oxide nanocomposites with unique band gap and electronic structure for thermochromic energy saving applications.

scholarly journals The Interaction between Graphene and Oxygen Atom

Open Physics ◽  
2016 ◽  
Vol 14 (1) ◽  
pp. 690-694 ◽  
Author(s):  
Yifan Hao ◽  
Xuejun Zhao ◽  
Xuedan Song ◽  
Hongjiang Li ◽  
Xiaobing Zhu ◽  
...  
Keyword(s):  
Reaction Mechanism ◽  
Oxygen Atom ◽  
Potential Energy ◽  
Potential Energy Surface ◽  
Density Function ◽  
Energy Surface ◽  
Function Theory ◽  
Dft Method ◽  
Density Function Theory ◽  
Basis Set

AbstractBased on the density function theory (DFT) method, the interaction between the graphene and oxygen atom is simulated by the B3LYP functional with the 6-31G basis set. Due to the symmetry of graphene (C54H18, D6h), a representative patch is put forward to represent the whole graphene to simplify the description. The representative patch on the surface is considered to gain the potential energy surface (PES). By the calculation of the PES, four possible stable isomers of the C54H18-O radical can be obtained. Meanwhile, the structures and energies of the four possible stable isomers, are further investigated thermodynamically, kinetically, and chemically. According to the transition states, the possible reaction mechanism between the graphene and oxygen atom is given.

scholarly journals Theoretical Investigation on Reaction Pathway, Biological Activity, Toxicity and NLO Properties of Diclofenac Drug and Its Ionic Carriers

2020 ◽  
pp. 936-951
Author(s):  
Mustafa M. Kadhim ◽  
Rehab M. Kubba
Keyword(s):  
Density Function ◽  
Function Theory ◽  
Reaction Pathway ◽  
Drug Carrier ◽  
Heat Of Formation ◽  
Density Function Theory ◽  
Basis Sets ◽  
Nlo Properties ◽  
Hartree Fock ◽  
The Common

The present study included the use of the approximate semi-experimental method, the time-independent density function theory (unrestricted), the time-dependent density function theory, and Hartree-Fock method to calculate the reaction pathway of the anti-inflammatory drug diclofenac with its common ionic carriers (sodium and potassium). The basis sets used were STO-3G, 3-21G, 6-31G, and 6-311G. The drug was studied with two new proposed carrier ions (lithium and calcium) which were compared with common carriers. The calculations included the optimized geometrical structure and some physical properties such as standard heat of formation, dipole moment, total energies, and analytical spectra of IR, UV-VIS and 1H NMR. The biological and toxicological activities and the nonlinear optical (NLO) properties were also studied theoretically for the drug and for its proposed and common carriers. All calculations were performed using Gaussian-09 program. The results of the proposed carriers were compared with the common carriers in terms of activation energies, transition states, and products. This study is considered as a step to develop diclofenac prodrugs and find new carriers for diclofenac. The proposed lithium showed a good result and a potential for use as a drug carrier. The results also showed the convergence of the values of the common carriers (Na, K) and those of the proposed carrier (Ca), with their preference over it.

Analysis of the Ring-Closing of Chloride Polyether Polyol by the Method of Quantum Chemical Calculating

2010 ◽  
Vol 160-162 ◽  
pp. 630-633
Author(s):  
Jian Li ◽  
Xun Zhang Yu ◽  
Kai Zhang
Keyword(s):  
Total Energy ◽  
Density Function ◽  
Quantum Chemical ◽  
Function Theory ◽  
Transition States ◽  
Dft Method ◽  
Density Function Theory ◽  
Calculation Results ◽  
Polyether Polyol ◽  
Oxygen Bond

The ring-closing reaction of chloride polyether polyol was calculated by Gaussian03 software. The Density Function Theory (DFT) method were employed to study the geometry structures of chloride polyether polyol and the product was obtained on the base of B3LYP/6-31G+ model in this paper. The transitional states (Ts1, Ts2) during the ring-closing process were found by TS method and the energy changing of the system was proved by IRC calculation. Results showed that the ring-closing of chloride polyether polyol had two transition states: hydrogen transferring and the formation of new carbon-oxygen bond. The total energy of reactants was -1459.99627a.u and product is -1460.31170 a.u. The energy of the system was reduced by 175.47621kJ/mol. The ring-closing of chloride polyether polyol was exothermic and stable in thermodynamics.

scholarly journals Synthesis and Characterisation of Copper(II) Complexes with Tridentate NNO Functionalized Ligand: Density Function Theory Study, DNA Binding Mechanism, Optical Properties, and Biological Application

2014 ◽  
Vol 2014 ◽  
pp. 1-13 ◽  
Author(s):  
Madhumita Hazra ◽  
Tanushree Dolai ◽  
Akhil Pandey ◽  
Subrata Kumar Dey ◽  
Animesh Patra
Keyword(s):  
Density Function ◽  
Antimicrobial Agents ◽  
Function Theory ◽  
Free Ligand ◽  
Fluorescence Emission ◽  
Building Blocks ◽  
Density Function Theory ◽  
Calf Thymus Dna ◽  
Spectroscopic Techniques ◽  
Calf Thymus

The photo physical properties of two mononuclear pentacoordinated copper(II) complexes formulated as [Cu(L)(Cl)(H2O)] (1) and [Cu(L)(Br)(H2O)] (2)HL = (1-[(3-methyl-pyridine-2-ylimino)-methyl]-naphthalen-2-ol) were synthesized and characterized by elemental, physicochemical, and spectroscopic methods. The density function theory calculations are used to investigate the electronic structures and the electronic properties of ligand and complex. The interactions of copper(II) complexes towards calf thymus DNA were examined with the help of absorption, viscosity, and fluorescence spectroscopic techniques at pH 7.40. All spectroscopy's result indicates that complexes show good binding activity to calf thymus DNA through groove binding. The optical absorption and fluorescence emission properties of microwires were characterized by fluorescence microscope. From a spectroscopic viewpoint, all compounds strongly emit green light in the solid state. The microscopy investigation suggested that microwires exhibited optical waveguide behaviour which are applicable as fluorescent nanomaterials and can be used as building blocks for miniaturized photonic devices. Antibacterial study reveals that complexes are better antimicrobial agents than free Schiff base due to bacterial cell penetration by chelation. Moreover, the antioxidant study of the ligand and complexes is evaluated by using 1,1-diphenyl-2-picrylhydrazyl (DPPH) free-radical assays, which demonstrate that the complexes are of higher antioxidant activity than free ligand.

exo- and endo-Complexes of Fe(0) with Carbon Allotropic Modifications on the Example of Fullerene С60: a Density Function Theory Study

2021 ◽  
Vol 91 (5) ◽  
pp. 828-834
Author(s):  
K. V. Zaitsev ◽  
A. Yu. Oprunenko ◽  
I. P. Gloriozov ◽  
M. S. Nechaev ◽  
Yu. F. Oprunenko ◽  
...  
Keyword(s):  
Density Function ◽  
Function Theory ◽  
Density Function Theory ◽  
Allotropic Modifications
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