Theoretical study of the oxidation mechanisms of naphthalene initiated by hydroxyl radicals: the O2 addition reaction pathways

2015 ◽  
Vol 17 (20) ◽  
pp. 13719-13732 ◽  
Author(s):  
A. Shiroudi ◽  
M. S. Deleuze ◽  
S. Canneaux
Keyword(s):  
Hydroxyl Radicals ◽  
Ground State ◽  
Density Functional ◽  
Theoretical Study ◽  
Addition Reaction ◽  
Reaction Pathways ◽  
Functional Theory ◽  
Exchange Correlation ◽  
Oxidation Mechanisms ◽  
Electronic Ground

Atmospheric oxidation of the naphthalene–OH adduct [C10H8OH]˙ (R1) by molecular oxygen in its triplet electronic ground state has been studied using density functional theory along with the B3LYP, ωB97XD, UM05-2x and UM06-2x exchange–correlation functionals.

Theoretical Study of Ethylene Addition to O=W(=CH2)(CH3)2

2007 ◽  
Vol 62 (3) ◽  
pp. 367-372 ◽  
Author(s):  
Robin Haunschild ◽  
Gernot Frenking
Keyword(s):  
Density Functional ◽  
Theoretical Study ◽  
Activation Barrier ◽  
Reaction Pathways ◽  
Theoretical Studies ◽  
Stable Isomer ◽  
Functional Theory ◽  
B3lyp Level ◽  
Rhenium Compound ◽  
Favorable Reaction

Quantum chemical calculations using density functional theory at the B3LYP level of theory were carried out to investigate the reaction pathways for the addition of ethylene to WO(CH3)2(CH2) (W1). The results are compared to those of previous theoretical studies of the ethylene addition to OsO3(CH2) (Os1) and ReO2(CH3)(CH2) (Re1). The theoretically predicted reactions pathways exhibit significant differences. The energetically most favourable reaction of the tungsten system W1 is the [2+2]W,C addition across theW=C double bond yielding the metallacyclobutane W3a which then rearranges to the slightly more stable isomer W3b. The [2+2]Re,C addition of the rhenium compound yielding the metallacyclobutane Re3a has the lowest activation barrier for the ethylene addition to the rhenium system, but the reaction is endothermic while the exothermic formation of the more stable isomer Re3b has a much higher activation barrier. The [3+2]C,O addition Os1+C2H4→Os2 is the thermodynamically most favorable reaction of the osmium compound.

MAGNETIC MAP OF MnNi ALLOYED MONOLAYER ON Cu(001) SUBSTRATE: AB-INITIO CALCULATIONS

2010 ◽  
Vol 09 (06) ◽  
pp. 619-622
Author(s):  
BOTHINA A. HAMAD
Keyword(s):  
Density Functional ◽  
Theoretical Study ◽  
Magnetic Moments ◽  
Generalized Gradient ◽  
Functional Theory ◽  
Exchange Correlation ◽  
Generalized Gradient Approximation ◽  
Exchange Correlation Potential ◽  
The Density Functional Theory ◽  
Correlation Potential

In this work, a theoretical study of the structural, electronic and magnetic properties are presented for Mn 0.5 Ni 0.5 alloyed overlayer adsorbed on Cu (001) surface. The calculations were performed using the density functional theory (DFT) and the exchange-correlation potential was treated by the generalized gradient approximation (GGA). The system was fully relaxed except for the central layer, which yields to outward relaxations and inward Mn and Ni surface atoms, respectively in the ferromagnetic and antiferromagnetic configurations. The in-plane ferromagnetic configuration was found to be more stable than the antiferromagnetic one by 25 meV/atom. The local magnetic moments of Mn atoms were found to be about 4 μ B , whereas those of the Ni atoms where found to be 0.46 μ B .

scholarly journals London dispersion forces without density distortion: a path to first principles inclusion in density functional theory

2020 ◽  
Vol 224 ◽  
pp. 145-165
Author(s):  
Derk Pieter Kooi ◽  
Paola Gori-Giorgi
Keyword(s):  
Ground State ◽  
First Principles ◽  
Density Functional ◽  
Dispersion Forces ◽  
Density Functionals ◽  
Functional Theory ◽  
Exchange Correlation ◽  
State Densities ◽  
London Dispersion ◽  
London Dispersion Forces

We analyse a path to construct density functionals for the dispersion interaction energy from an expression in terms of the ground state densities and exchange–correlation holes of the isolated fragments.

scholarly journals Theoretical study on the reaction mechanism of “ligandless” Ni-catalyzed hydrodesulfurization of aryl sulfide

RSC Advances ◽  
2017 ◽  
Vol 7 (81) ◽  
pp. 51475-51484 ◽  
Author(s):  
Sheng Fang ◽  
Meiyan Wang ◽  
Jingjing Liu ◽  
Bingwen Li ◽  
Jing-yao Liu
Keyword(s):  
Density Functional Theory ◽  
Reaction Mechanism ◽  
Density Functional ◽  
Theoretical Study ◽  
Reaction Pathways ◽  
Competitive Reaction ◽  
Functional Theory ◽  
Aryl Sulfide

The reaction mechanism of Ni(COD)2 catalyzed hydrodesulfurization of aryl sulfide PhSMe with HSiMe3 has been predicted to have two competitive reaction pathways, with or without PhSMe spectator ligand, by using density functional theory methods.

scholarly journals A theoretical study on the regio- and stereoselectivity of [3+2] cycloaddition of 2-(trifluoroacetyl)vinyl ethyl ether to 2-arylidene-5-oxopyrazolidin-2-ium-1-ides

2018 ◽  
Vol 83 (3) ◽  
pp. 285-303
Author(s):  
Mina Haghdadi ◽  
Nasim Nab
Keyword(s):  
Gas Phase ◽  
Ethyl Ether ◽  
Density Functional ◽  
Theoretical Study ◽  
Reaction Pathways ◽  
Dft Methods ◽  
Functional Theory ◽  
Remarkable Effect ◽  
Phase Selectivity ◽  
Good Agreement

[3+2] Cycloaddition reactions of 2-(trifluoroacetyl)vinyl ethyl ether (1) to substituted and unsubstitued 2-arylidene-5-oxopyrazolidin-2-ium-1-ides (2a?e) were studied using density functional theory (DFT) methods at the cc-pVDZ level. The mechanistic details of these reactions, especially with respect to regio- and stereoselectivity, were analyzed. Analysis of the relative energies that are associated with the different reaction pathways indicated that the presence of the trifluoroacetyl group in the dipolarophile and substituents on the aryl ring in the dipolar have a remarkable effect on selectivity. In addition, it was found that the ortho?endo pathway with the lowest activation energy is preferred, which is in good agreement with the experimental data. Moreover, the elimination of ethanol from the [3+2] cycloadducts and the formation of bicyclic pyrazolidinones are explained in order to give a total description of the complete domino processes. The inclusion of solvent effects increased the activation energies and the exothermic character of the cycloadducts, but did not change the gas phase selectivity. The DFT-based reactivity indices clearly predicted the experimental regiochemistry.

scholarly journals First principles calculations of the electronic and dielectric properties of λ-Ta2O5

TecnoLógicas ◽  
2018 ◽  
Vol 21 (43) ◽  
pp. 43-52 ◽  
Author(s):  
Camilo Valencia-Balvín ◽  
Santiago Pérez-Walton ◽  
Jorge M. Osorio-Guillén
Keyword(s):  
Density Functional Theory ◽  
First Principles ◽  
Density Functional ◽  
Theoretical Study ◽  
Wide Bandgap ◽  
First Principles Calculations ◽  
Functional Theory ◽  
Wide Bandgap Semiconductor ◽  
Exchange Correlation ◽  
Good Agreement

Ta2O5 is a wide-bandgap semiconductor that offers interesting applications in microwavecommunications, mainly related to the manufacture of filters and resonators whosesize is inversely proportional to the dielectric constant of the material. For that reason, inthis work we present a theoretical study, based on density functional theory (using PBEsoland hybrid HSE06 exchange-correlation functionals), of the electronic and dielectricproperties of the orthorhombic model -Ta2O5. We found that this model has a direct gap of2.09 and 3.7 eV with PBEsol and HSE06, respectively. Furthermore, the calculated staticdielectric constant, 51, is in good agreement with the reported values of other phases of thissemiconductor.

Second order hyperpolarizability of triphenylamine based organic sensitizers: a first principle theoretical study

RSC Advances ◽  
2016 ◽  
Vol 6 (79) ◽  
pp. 75242-75250 ◽  
Author(s):  
M. Prakasam ◽  
P. M. Anbarasan
Keyword(s):  
Density Functional Theory ◽  
Ground State ◽  
Density Functional ◽  
Theoretical Study ◽  
Time Dependent ◽  
First Principle ◽  
Functional Theory ◽  
Metal Free ◽  
Td Dft ◽  
Organic Sensitizers

Designed metal-free dyes have been investigated by Density Functional Theory (DFT) and Time-Dependent DFT (TD-DFT) to evaluate the ground state and excited state geometries of triphenylamine-based organic sensitizers.

Electronic shell structure of antimony cluster

1992 ◽  
Vol 70 (12) ◽  
pp. 1205-1208
Author(s):  
B. N. Onwuagba
Keyword(s):  
Binding Energy ◽  
Ground State ◽  
Density Functional ◽  
Magic Numbers ◽  
Local Spin Density Approximation ◽  
Correlation Effects ◽  
Jellium Model ◽  
Functional Theory ◽  
Exchange Correlation ◽  
Relative Binding

The ground-state properties of antimony clusters are investigated in the framework of density functional theory. The exchange correlation effects were included in the local spin density approximation and a spherical jellium model is used to calculate the total energy, binding energy, relative binding-energy change, and ionization potential with a view to understanding the mechanism leading to the magic-numbers exhibited by this class of higher valence clusters.

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