[TM13@Bi20]− clusters in three-shell icosahedral matryoshka structure: being as superatoms

RSC Advances ◽  
2015 ◽  
Vol 5 (112) ◽  
pp. 92134-92143 ◽  
Author(s):  
C. Y. Kou ◽  
L. Zhuang ◽  
G. Q. Wang ◽  
H. Cui ◽  
H. K. Yuan ◽  
...  
Keyword(s):  
Density Functional Theory ◽  
Density Functional ◽  
Dft Method ◽  
Functional Theory ◽  
The Density Functional Theory

Using the density functional theory (DFT) method, three-shell icosahedral matryoshka [TM13@Bi20]− clusters (TM = 3d, 4d) have been systematically examined to explore the possibility of clusters being as superatoms.

First principles analysis of oxygen vacancy formation and migration in Sr2BMoO6 (B = Mg, Co, Ni)

RSC Advances ◽  
2016 ◽  
Vol 6 (38) ◽  
pp. 31968-31975 ◽  
Author(s):  
Shuai Zhao ◽  
Liguo Gao ◽  
Chunfeng Lan ◽  
Shyam S. Pandey ◽  
Shuzi Hayase ◽  
...  
Keyword(s):  
Density Functional Theory ◽  
Oxygen Vacancy ◽  
First Principles ◽  
Density Functional ◽  
Dft Method ◽  
Double Perovskites ◽  
Functional Theory ◽  
Oxygen Vacancy Formation ◽  
The Density Functional Theory ◽  
And Migration

In this work, we present a detailed first-principles investigation on the stoichiometric and oxygen-deficient structures of double perovskites, Sr2BMoO6 (B = Mg, Co and Ni), using the density functional theory (DFT) method.

scholarly journals Chloroquine drug and Graphene complex for treatment of COVID-19

2020 ◽  
Author(s):  
Saeedeh Mohammadi ◽  
Mohammad Esmailpour ◽  
Mina Mohammadi
Keyword(s):  
Density Functional Theory ◽  
Density Functional ◽  
Energy Gap ◽  
Dft Method ◽  
Complex State ◽  
Functional Theory ◽  
The Density Functional Theory ◽  
Structural And Electrical Properties ◽  
Suitable Structure ◽  
Drug Complex

Abstract This paper is a new step in helping the treatment of coronavirus by improving the performance of chloroquine drug. For this purpose, we propose a complex of chloroquine drug with graphene nanoribbon (GNR) scheme. We compute the structural and electrical properties and absorption of chloroquine (C18H26ClN3) and GNR complex using the density functional theory (DFT) method. By creating a drug and GNR complex, the density of states of electrons increases and the energy gap decreases compared to the chloroquine. Also, using absorption calculations and spectrums such as infrared and UV-Vis spectra, we showed that GNR is a suitable structure for creating chloroquine drug complex. Our results show that the dipole moment, global softness and electrophilicity for the drug complex increases compared to the non-complex state. Our calculations can be useful for increasing performance and reducing the side effects of chloroquine, and thus can be effective in treating coronavirus.

scholarly journals Theoretical Calculations on the Mechanism of Enantioselective Copper(I)-Catalyzed Addition of Enynes to Ketones

Catalysts ◽  
2018 ◽  
Vol 8 (9) ◽  
pp. 359 ◽  
Author(s):  
Hanwei Li ◽  
Mingliang Luo ◽  
Guohong Tao ◽  
Song Qin
Keyword(s):  
Density Functional Theory ◽  
Steric Hindrance ◽  
Phenyl Ring ◽  
Density Functional ◽  
Theoretical Calculations ◽  
Dft Method ◽  
Catalytic Cycle ◽  
Functional Theory ◽  
The Density Functional Theory ◽  
Chiral Systems

Computational investigations on the bisphospholanoethane (BPE)-ligated Cu-catalyzed enantioselective addition of enynes to ketones were performed with the density functional theory (DFT) method. Two BPE-mesitylcopper (CuMes) catalysts, BPE-CuMes and (S,S)-Ph-BPE–CuMes, were employed to probe the reaction mechanism with the emphasis on stereoselectivity. The calculations on the BPE-CuMes system indicate that the active metallized enyne intermediate acts as the catalyst for the catalytic cycle. The catalytic cycle involves two steps: (1) ketone addition to the alkene moiety of the metallized enyne; and (2) metallization of the enyne followed by the release of product with the recovery of the active metallized enyne intermediate. The first step accounts for the distribution of the products, and therefore is the stereo-controlling step in chiral systems. In the chiral (S,S)-Ph-BPE–CuMes system, the steric hindrance is vital for the distribution of products and responsible for the stereoselectivity of this reaction. The steric hindrance between the phenyl ring of the two substrates and groups at the chiral centers in the ligand skeleton is identified as the original of the stereoselectivity for the titled reaction.

DENSITY FUNCTIONAL THEORY STUDY ON THE MECHANISM OF TRIMETHYLAMINE-CATALYZED BAYLIS–HILLMAN REACTION

2010 ◽  
Vol 09 (supp01) ◽  
pp. 65-75 ◽  
Author(s):  
JING LI ◽  
WAN-YI JIANG
Keyword(s):  
Density Functional Theory ◽  
Density Functional ◽  
Dft Method ◽  
Polarizable Continuum Model ◽  
Functional Theory ◽  
Reaction Barrier ◽  
Hydrogen Shift ◽  
Rate Determining Step ◽  
The Density Functional Theory ◽  
Polarizable Continuum

The trimethylamine-catalyzed Baylis–Hillman reaction of formaldehyde and vinylaldehyde has been studied with the density functional theory (DFT) method of B3LYP/6-31+G(d,p). In the gas phase, the reaction involves an amine–formaldehyde–vinylaldehyde trimolecular addition transition structure followed by rate-determining intramolecular 1,3-hydrogen shift. When a bulk solvent effect of water was considered with conductor-like polarizable continuum model (CPCM), the reaction was found to follow the sequence of Michael-addition of amine to vinylaldehyde (step 1), addition of formaldehyde (step 2), and 1,3-hydrogen shift (step 3), with the 1,3-hydrogen shift as rate-determining. The overall reaction barrier is significantly reduced. When a molecule of water is involved in the reaction, the 1,3-hydrogen shift is significantly promoted so that the rate-determining step becomes the C–C bond formation. The calculated overall reaction barrier is in agreement with experimental observations.

scholarly journals CALCULATION OF THE ELECTRONIC STRUCTURE OF SOME EPOXY MOLECULES BY THE DFT METHOD

2021 ◽  
pp. 32-34
Author(s):  
V. A. Babkin ◽  
D. S. Andreev ◽  
E. S. Titova ◽  
A. V. Ignatov ◽  
R. O. Boldyrev ◽  
...  
Keyword(s):  
Density Functional Theory ◽  
Electronic Structure ◽  
Quantum Chemical Calculation ◽  
Quantum Chemical ◽  
Density Functional ◽  
Dft Method ◽  
Chemical Calculation ◽  
Functional Theory ◽  
The Density Functional Theory

In this work, we performed a quantum-chemical calculation of some epoxy molecules: 1,2-epoxy-butene, 1,2-epoxy-2-methylpropane, 1,2 epoxyethane by the density functional theory DFT. An optimized geometric and electronic structure of these compounds is obtained. It was found that the studied epoxides belong to the class of very weak СH-acids (pKa = 28-30).

scholarly journals A DFT reinvestigation of chemo- and stereoselectivity epoxidation from α- and ɣ-trans himachalene with meta Chloroperoxybenzoic acid

2019 ◽  
Vol 9 (2) ◽  
pp. 133-141
Author(s):  
Abdelhak Ouled Aitouna ◽  
Lahoucine Bahsis ◽  
Hicham Ben El Ayouchia ◽  
Ahmed Chekroun ◽  
Redouan Hammal ◽  
...  
Keyword(s):  
Density Functional Theory ◽  
Double Bond ◽  
Density Functional ◽  
Dft Method ◽  
Conceptual Density Functional Theory ◽  
Functional Theory ◽  
Reactivity Indices ◽  
Epoxidation Reaction ◽  
The Density Functional Theory ◽  
Shed Light

In this work the epoxidation reaction of the α- and ɣ-trans himachalene in the presence of meta chloroperoxybenzoic acid (m-CPBA) has been studied within the Density Functional Theory (DFT) method at the B3LYP/6-311G(d,p) level in dichloromethane as a solvent, in order to shed light on the chemo- and stereoselectivity in the course of the reaction. Analysis of the Conceptual Density Functional Theory (CDFT) reactivity indices indicate that the m-CPBA will behave as electrophilic while α- and ɣ-trans himachalene will behave as a nucleophile and the attacks observed experimentally are correctly predicted by the electrophilic Pk + and nucleophilic Pk - Parr functions. The two reactive paths associated with chemo and stereoselectivity approach modes of m-CPBA on C=C reactive sites in α and ɣ-trans himachalene have been analyzed. They showed that m-CPBA reacted as electrophile whereas α- and ɣ- trans himachalene as a nucleophile. The Monoepoxidation of α- and ɣ- trans himachalene leads to the formation of two stereoisomers, on the most substituted double bond "C=C», one of the two is a majority. The diepoxidation reaction of α- and ɣ- trans h

Density Functional Theory Investigation and Detonation Characterization of DNPDNAZ

2014 ◽  
Vol 997 ◽  
pp. 264-267
Author(s):  
Hong Ya Li ◽  
Tian Tian Zhang
Keyword(s):  
Density Functional Theory ◽  
Density Functional ◽  
Dft Method ◽  
Detonation Pressure ◽  
Functional Theory ◽  
The Density Functional Theory ◽  
Equivalent Equation ◽  
Molecular Reactivity ◽  
Density Results

N-2’,4’-dinitrophenyl-3,3-dinitroazetidine (DNPDNAZ) is an important derivative of 3,3-dinitroazetidine (DNAZ). The density functional theory (DFT) method of the Amsterdam density functional (ADF) was used to calculate the geometry and frequencies. The detonation velocity (D) and detonation pressure (P) of DNPDNAZ were estimated using the nitrogen equivalent equation according to the experimental density. Results showed that the initial decomposition step of DNPDNAZ is the loss of NO2from C2 and N1 is the point of molecular reactivity,DandPare 7364.42 m·s-1and 23.75 GPa, respectively.

Synthesis of [Re2Cl4(O)2(µ-O)(3,5-lut)4] and investigation of its structure via X-ray and spectroscopic measurements and DFT calculations

2014 ◽  
Vol 68 (5) ◽  
Author(s):  
Sławomir Michalik ◽  
Jan Małecki ◽  
Natalia Młynarczyk
Keyword(s):  
Density Functional Theory ◽  
Density Functional ◽  
Computational Study ◽  
Dft Method ◽  
Time Dependent ◽  
Electronic Transitions ◽  
X Ray Diffraction ◽  
Functional Theory ◽  
X Ray ◽  
The Density Functional Theory

AbstractA combined experimental and computational study of the dinuclear rhenium(V) complex containing (ReO)2(µ-O) core is presented in this article. The solid-state [Re2Cl4(O)2(µ-O)(3,5-lut)4] (3,5-lut = 3,5-dimethylpyridine) complex was characterised structurally (by single crystal X-ray diffraction) and spectroscopically (by IR, NMR, UV-VIS). The electronic structure was examined using the density functional theory (DFT) method. The spin-allowed electronic transitions were calculated using the time-dependent DFT method, and the UV-VIS spectrum was discussed.

Density functional theory investigations on the coordination of Pa(v) with N,N-dialkylamide

2020 ◽  
Vol 44 (22) ◽  
pp. 9477-9484
Author(s):  
Jun Ma ◽  
Chuting Yang ◽  
Jun Han ◽  
Sheng Hu ◽  
Haizhu Yu ◽  
...  
Keyword(s):  
Aqueous Solution ◽  
Density Functional Theory ◽  
Density Functional ◽  
Dft Method ◽  
Functional Theory ◽  
The Density Functional Theory ◽  
Shed Light

The density functional theory (DFT) method was used to study the coordination of a series of N,N-dialkylamides with Pa(v) to shed light on the inherent principles for screening amide extractants of Pa(v) from aqueous solution.

DFT-PCM STUDIES OF THE SOLVENT EFFECTS ON THE ABSORPTION PROPERTIES OF DCM

2006 ◽  
Vol 05 (04) ◽  
pp. 957-965 ◽  
Author(s):  
BO-CHENG WANG ◽  
CHIN-KUEN TAI
Keyword(s):  
Density Functional Theory ◽  
Density Functional ◽  
Solvent Polarity ◽  
Dft Method ◽  
Polarizable Continuum Model ◽  
Maximum Absorption ◽  
Functional Theory ◽  
The Density Functional Theory ◽  
Td Dft ◽  
Solvent Environment

In this paper, we have performed the optimized structures of the red emitting material, 4-(dicyanomethylene)-2-methyl-6-[p-(dimethyl amino) styryl]-4H-pyran (DCM), with different polarity solvent environments by using the density functional theory (DFT) method, B3LYP/6-31G*. The time-dependent density functional theory (TD-DFT) and the polarizable continuum model (PCM) have been used to obtain the optical properties in the solvent environment. It has been observed that when the solvent polarity increases, the DCM molecule exhibits the red shift in the maximum absorption wavelength [Formula: see text] and enhances the oscillator strength (f). The solvent polarity also enhances the electron transfer ability from the electron-donating dimethylamine group (-N(CH3)2) to the electron-withdrawing =C(CN)2 group. The S 0 → S 1 transition of DCM is found to be π–π*. The maximum absorption wavelengths [Formula: see text] of different solvent environments are found to be consistent with the reported experimental results.

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