A Computational Study on Structural and Electronic Properties of 1-(4-Chlorophenyl)-2-{[5-(4-Chlorophenyl)-1,2,3-Oxadiazol-2-Yl]Sulfanyl}Ethanone

2019 ◽  
Vol 892 ◽  
pp. 1-7
Author(s):  
Pek Lan Toh ◽  
Montha Meepripruk ◽  
Rosfayanti Rasmidi
Keyword(s):  
Density Functional ◽  
Computational Study ◽  
Molecular System ◽  
Population Analysis ◽  
Atomic Charge ◽  
Dft Method ◽  
Basis Sets ◽  
Hydrogen Atoms ◽  
Mulliken Population ◽  
Total Energies

In this paper, a first principle Density Functional Theory (DFT) method was conducted to study the geometric and electronic structures of 1-(4-chlorophenyl)-2-{[5-(4-chlorophenyl) -1,3,4-oxadiazol-2-yl] sulfanyl} ethanone, C16H10Cl2N2O2S. Using B3LYP level of theory with four basis sets of 6-31G**, 6-31++G**, 6-311G**, and 6-311++G**, the equilibrium structure of the title molecule was used to determine the total energies, Frontier molecular orbital’s energies, Mulliken atomic charges, and others. The computed findings present that four total energies obtained are close to each other, with the corresponding values of-59716.06 eV, -59709.42 eV, -59708.56 eV, and-59716.51 eV, respectively for B3LYP/6-31G**, B3LYP/6-31++G**, B3LYP/6-311G**, and B3LYP/6-311++G** methods. The calculated HOMO-LUMO energy gaps were predicted in the range of 4.001 eV - 4.089 eV. In this study, the atomic charge values of molecular system were also determined using Mulliken Population Analysis (MPA) approach. For DFT/B3LYP/6-311G** level of calculation, the computed results show that the atom of C8 accommodates the highest negative charge in the title molecular system. All the oxygen, nitrogen, and chloride atoms are having negative charges, whereas all the hydrogen atoms are having positive charges. In addition, the dipole moment value was also determined to be 1.4758 Debye by employing DFT/B3LYP/6-311G** level of theory.

scholarly journals First Principles Study on the Stability and Electronic Structures of 7,8-Dichloro-4-Oxo-4H-Chromene-3-Carbaldehyde

2016 ◽  
Vol 855 ◽  
pp. 31-36
Author(s):  
Pek Lan Toh ◽  
Montha Meepripruk ◽  
Lee Sin Ang ◽  
Shukri Sulaiman ◽  
Mohamed Ismail Mohamed-Ibrahim
Keyword(s):  
Electronic Structures ◽  
Density Functional ◽  
Molecular System ◽  
Population Analysis ◽  
Measurement Data ◽  
Geometry Optimization ◽  
Molecular Structures ◽  
Basis Sets ◽  
Mulliken Population ◽  
Homo Lumo

The molecular structures and electronic properties of 7,8-Dichloro-4-Oxo-4H-Chromene-3-Carbaldehyde, C10H4Cl2O3 have been studied using Density Functional Theory (DFT) method. The calculation of geometry optimization was conducted to find the local energy minimum of C10H4Cl2O3 molecular system. The equilibrium geometries were used to determine the HOMO-LUMO gaps, Mulliken atomic charges, and other electronic structures of C10H4Cl2O3. The significant findings from DFT/B3LYP functional within the basis sets of 6-31G**, 6-31++G**, 6-311G**, and 6-311++G** show that the optimized geometries of C10H4Cl2O3 are in good agreement with that of measurement data. To further investigate this, using a variety of basis sets (3-21G, 6-31G, 6-31++G, 6-31G**, 6-31++G**, 6-311G, 6-311++G, 6-311G**, and 6-311++G**), it is found that the calculated total energy values of C10H4Cl2O3 are close to each other. Similarly, the computed HOMO-LUMO energy gaps obtained are also close to each other. Using the scheme of Mulliken Population Analysis (MPA), the trend of findings are the same for both cases of B3LYP/6-31G and B3LYP/6-31G** level of calculations. For the method of B3LYP/6-31G, it is clearly found that C4 and C6 have the highest positively charge, with the corresponding values about +0.284 and +0.238, respectively. On the other hand, the charge values of +0.157 and +0.206 are found on Cl1 and Cl2 atoms. The atoms of O1, O2, and O3 have the negatively charges, with the values of about 0.398, -0.512, and -0.424, respectively. Similarly, in the case of DFT/B3LYP/6-31G** level of theory, the computed charge values of C2 and C4 are about +0.311 and +0.393, respectively. Furthermore, the Cl1 and Cl2 atoms have the positively charge values of about +0.043 and +0.070, whereas for the O1, O2, and O3 atoms, the charges values obtained are about -0.421, -0.467, and -0.498, respectively.

Theoretical study of the geometrical and electronic properties of Be2Mg+ n (n = 1–11) clusters

2019 ◽  
Vol 9 (7) ◽  
pp. 778-785 ◽  
Author(s):  
Ben-Chao Zhu ◽  
Zhang Yu ◽  
Wang Ping ◽  
Lu Zeng ◽  
Shuai Zhang
Keyword(s):  
Electronic Properties ◽  
Ground State ◽  
Density Functional ◽  
Population Analysis ◽  
Dft Method ◽  
Mulliken Population ◽  
Functional Theory ◽  
Fragmentation Energy ◽  
Average Binding Energy ◽  
Ground State Structures

By using Density Functional Theory (DFT) method at the B3LYP/6-311G level, the structures, stabilities, and electronic properties of cationic Be2Mg+ n (n = 1–11) clusters have been systematically studied. The optimized geometry show that the ground state structures of cationic Be2Mg+ n (n = 1–11) clusters favor 3D structures except n = 1, 2. Furthermore, the average binding energy E b, the second-order energy differences Δ2E, the fragmentation energy Ef and the HOMO-LUMO energy Egap of the ground state of cationic Be2Mg– n (n = 1–11) clusters are calculated, the final results indicate that Be2Mg+6 and Be2Mg+9 clusters have a higher stability than other clusters. Additionally, the NCP, NEC and Mulliken population analysis reveal that the charges in cationic Be2Mg+ n (n = 1–11) clusters transfer from Mg atom to Be atoms, and strong sp hybridizations are presented in Be atoms of Be2Mg+ n clusters. Finally, the polarizability analysis indicates that the nuclei and electronic clouds of clusters are affected by external field with the increase of cluster size.

X-ray and DFT Investigation of (E)-4-bromo-5-methoxy-2-((o-tolylimino)methyl)phenol Compound

2018 ◽  
pp. 454-461
Keyword(s):  
Density Functional ◽  
Theoretical Calculations ◽  
Population Analysis ◽  
Diffraction Method ◽  
Dft Method ◽  
Basis Set ◽  
X Ray Diffraction ◽  
Mulliken Population ◽  
Charge Delocalization ◽  
X Ray

(E)-4-bromo-5-methoxy-2-((o-tolylimino)methyl)phenol was investigated by experimental and theoretical methodologies. The solid state molecular structure was determined by X-ray diffraction method. All theoretical calculations were performed by density functional theory (DFT) method by using B3LYP/6-31G(d,p) basis set. The titled compound showed the preference of enol form, as supported by X-ray diffraction method. The geometric and molecular properties were compaired for both enol-imine and keto-amine forms for title compound. Stability of the molecule arises from hyperconjugative interactions, charge delocalization and intramolecular hydrogen bond has been analyzed using natural bond orbital (NBO) analysis. Mulliken population method and natural population analysis (NPA) have been studied. Also, condensed Fukui function and relative nucleophilicity indices calculated from charges obtained with orbital charge calculation methods (NPA). Molecular electrostatic potential (MEP) and non linear optical (NLO) properties are also examined.

New Chalcone Derivative: Synthesis, Characterization, Computational Studies and Antioxidant Activity

2019 ◽  
Vol 17 (1) ◽  
pp. 46-53
Author(s):  
Reşat Ustabaş ◽  
Nevin Süleymanoğlu ◽  
Namık Özdemir ◽  
Nuran Kahriman ◽  
Ersan Bektaş ◽  
...  
Keyword(s):  
Antioxidant Activity ◽  
Density Functional ◽  
Computational Study ◽  
Dft Method ◽  
Basis Set ◽  
Basis Sets ◽  
Isomeric Form ◽  
Compound I ◽  
Chalcone Derivative ◽  
Reducing Ability

A new chalcone derivative, called as 1-(4-(benzylideneamino)phenyl)-3-(furan-2-yl)prop-2- en-1-one (I), was synthezised and characterized by spectral methods (infrared (IR) and proton and carbon- 13 nuclear magnetic resonance (1H- and 13C-NMR) spectroscopy). A computational study was performed by the density functional theory (DFT) method. Spectral data of compound I optimized by using 6-311G(d,p) and 6-311++G(d,p) basis sets were obtained by 6-311++G(d,p) basis set. The E-Z isomerism for newly synthesized chalcone derivative was investigated by considering four isomeric form, E/E, E/Z, Z/E and Z/Z. The results show that, as assumed and thus named, the chalcone derivative is in the E/E form. In addition, quantum chemical parameters were calculated by using DFT method with 6-311++G(d,p) basis set. Antioxidant activity of compound I was determined by the ferric reducing ability of plasma (FRAP) and 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay methods. Compound I has low antioxidant activity.

Quantum Mechanical Study of Clean and H-Covered α-MoO3(100) Surface

2003 ◽  
Vol 02 (02) ◽  
pp. 245-256 ◽  
Author(s):  
A. Sayede ◽  
B. Khelifa ◽  
C. Mathieu ◽  
H. Aourag
Keyword(s):  
Electronic Properties ◽  
Density Functional ◽  
Population Analysis ◽  
Chemical Properties ◽  
Hydrogen Atoms ◽  
Mulliken Population ◽  
Hartree Fock ◽  
Mechanical Study ◽  
Quantum Mechanical Study ◽  
Local Electronic Structure

Structure and electronic properties of the α-MoO3(100) surface, as well as H adsorption on the α-MoO3(100) surface have been studied with periodic slab Hartree–Fock calculations. Gradient corrected density functional calculations have been performed in this study. The structure and electronic properties of the (100) surface are in agreement with experimental and previous theoretical results. Local electronic structure near the different surface oxygen sites are analyzed with Mulliken Population Analysis. The oxide is partially ionic and the symmetrically oxygens exhibit more ionic feature while the terminal oxygens are more covalent. Electrostatic potentials show broad negative minima above the terminal oxygen centers, which suggest that electrophilic adparticles, like H, resulting from surface reactions, will be attracted preferentially at these sites. The results of the H adsorption on the (100) surface are interpreted based on charge-transfer interactions between the surface and H species. It is found that terminal oxygen sites are the most stable binding site. Ionic relaxation of the α-MoO3(100) surface for the adsorption of hydrogen has no effect on the chemical properties and hydrogen atoms adsorbed favorably on the α-MoO3(100) surface at full coverage.

scholarly journals Modelling carbyne C12-ring calcium decorated for hydrogen storage

2018 ◽  
Vol 64 (6) ◽  
pp. 634 ◽  
Author(s):  
Luis Alberto Desales Guzmán ◽  
Juan Horacio Pacheco Sánchez ◽  
Frank Jhonatan Isidro Ortega ◽  
Genoveva García Rosales
Keyword(s):  
Hydrogen Storage ◽  
Density Functional ◽  
Population Analysis ◽  
Generalized Gradient ◽  
Mulliken Population ◽  
Functional Theory ◽  
Weight Percentage ◽  
Average Binding Energy ◽  
Total Energies ◽  
Materials Studio

We computationally investigate the hydrogen storage properties of C12 carbyne structure decorated with one and up to six calcium (Ca) atoms adsorbed to outer surface. The calculations are carried out by density functional theory DFT with the generalized gradient approximation PW91 (Perdew and Wang) as implemented in the modeling and simulation Materials Studio software. Dmol3 is used to calculate, total energies, charge density HOMO-LUMO and Mulliken population analysis. Based on these results, up to six H2 molecules per Ca atom can be physisorbed with an average binding energy of 0.1272 eV per H2 molecule. The study is extended to a system with six calcium atoms, which can adsorb up to 36 H2 molecules. This leads to 15.87 weight percentage (wt %) for the gravimetric hydrogen storage capacity. According to these results, the calcium-coated carbyne C12 structure is a good candidate for hydrogen storage with application to fuel cells.

Quantum-Chemical Ab Initio Calculations on Inda- and Thallabenzene (C5H5In and C5H5Tl) and their Structural Isomers η5-C5H5In and η5-C5H5Tl

2018 ◽  
Vol 71 (3) ◽  
pp. 102
Author(s):  
Emma Persoon ◽  
Yuekui Wang ◽  
Gerhard Raabe
Keyword(s):  
Ab Initio ◽  
Quantum Chemical ◽  
Density Functional ◽  
Single Point ◽  
Normal Modes ◽  
Dft Method ◽  
Basis Sets ◽  
Triplet States ◽  
Structural Isomers ◽  
Td Dft

Quantum-chemical ab initio, time-independent, as well as time-dependent density functional theory (TD-DFT) calculations were performed on the so far elusive heterocycles inda- and thallabenzene (C5H5In and C5H5Tl), employing several different methods (MP2, CISD, CCSD, CCSD(T), BD, BD(T), QCISD, QCISD(T), CASSCF, DFT/B3LYP), effective core potentials, and different basis sets. While calculations on the MP2 level predict the ground states of the title compounds to be singlets with the first triplet states between 13 and 15 kcal mol−1 higher in energy, single point calculations with the QCISD(T), CCSD(T), and BD(T) methods at CCSD-optimized structures result in energy differences between the singlet and the triplet states in the range between 0.3 and 2.1 kcal mol−1 in favour of the triplet states. According to a CASSCF(8,8) calculation the triplets are also more stable by about 2.5–2.9 kcal mol−1. Calculations were also performed for the C5v-symmetric η5 structural isomers (cyclopentadienylindium, CpIn, and cyclopentadienylthallium, CpTl, Cp = C5H5) of the title compounds. At the highest level of theory employed in this study, C5H5In is between 79 and 88 kcal mol−1 higher in energy than CpIn, while this energy difference is even larger for thallabenzene where C5H5Tl is energetically between 94 and 102 kcal mol−1 above CpTl. In addition we report on the UV/vis spectra calculated with a TD-DFT method as well as on the spectra of the normal modes of C5H5In and C5H5Tl. Both types of spectra might facilitate identification of the title compounds eventually formed in photolysis or pyrolysis experiments.

scholarly journals Experimental and Density Functional Theory Characteristics of Ibrutinib, a Bruton’s Kinase Inhibitor Approved for Leukemia Treatment

2021 ◽  
Vol 2021 ◽  
pp. 1-8
Author(s):  
Ali I. Ismail
Keyword(s):  
Density Functional Theory ◽  
Density Functional ◽  
Kinase Inhibitor ◽  
Theoretical Calculations ◽  
Dft Method ◽  
Vibrational Frequencies ◽  
Basis Sets ◽  
Electronic Transitions ◽  
Functional Theory ◽  
Leukemia Treatment

Ibrutinib, a Bruton’s tyrosine kinase that plays an essential role in the B-cell development and cancer cells, has been recently approved to treat chronic, lymphocytic, and other types of leukemia. This study focused on investigating ibrutinib by its electronic transitions, vibrational frequencies, and electrospray mass spectra. The experimental peaks for electronic spectrum were found at 248.0 and 281.0 nm, whereas the νC = 0 stretching frequency was found at 1652.4 and 1639.19 cm−1. These experimental properties were compared with the corresponding theoretical calculations in which density functional theory was applied. The optimized structure was obtained with the calculations using a hybrid function (B3LYP) and high-level basis sets [6-311G++(d,p)]. Most of the calculated vibrational frequencies showed a relatively good agreement with the experimental ones. The electronic transitions of ibrutinib calculated using time-dependent DFT method were performed at two different solvation methods: PCM and SMD. The mass spectrum of ibrutinib, its fragments, and its isotopic pattern agreed well with the expected spectra.

scholarly journals Novel Insights into the Hydroxylation Behaviors of α-Quartz (101) Surface and its Effects on the Adsorption of Sodium Oleate

Minerals ◽  
2019 ◽  
Vol 9 (7) ◽  
pp. 450 ◽  
Author(s):  
Zhang ◽  
Xu ◽  
Hu ◽  
He ◽  
Tian ◽  
...  
Keyword(s):  
Sodium Oleate ◽  
Density Functional ◽  
Population Analysis ◽  
Water Molecules ◽  
Mulliken Population ◽  
Flotation Reagents ◽  
Functional Theory ◽  
Rigorous Study ◽  
Adsorption Energies ◽  
Hydroxylated Surface

A scientific and rigorous study on the adsorption behavior and molecular mechanism of collector sodium oleate (NaOL) on a Ca2+-activated hydroxylated α-quartz surface was performed through experiments and density functional theory (DFT) simulations. The rarely reported hydroxylation behaviors of water molecules on the α-quartz (101) surface were first innovatively and systematically studied by DFT calculations. Both experimental and computational results consistently demonstrated that the adsorbed calcium species onto the hydroxylated structure can significantly enhance the adsorption of oleate ions, resulting in a higher quartz recovery. The calculated adsorption energies confirmed that the adsorbed hydrated Ca2+ in the form of Ca(H2O)3(OH)+ can greatly promote the adsorption of OL− on hydroxylated quartz (101). In addition, Mulliken population analysis together with electron density difference analysis intuitively illustrated the process of electron transfer and the Ca-bridge phenomenon between the hydroxylated surface and OL− ions. This work may offer new insights into the interaction mechanisms existing among oxidized minerals, aqueous medium, and flotation reagents.

scholarly journals Synthesis, X-Ray Crystallography, Thermal Analysis, and DFT Studies of Ni(II) Complex with 1-Vinylimidazole Ligand

2014 ◽  
Vol 2014 ◽  
pp. 1-9 ◽  
Author(s):  
Fatih Şen ◽  
Ramazan Şahin ◽  
Muharrem Dinçer ◽  
Ömer Andaç ◽  
Murat Taş
Keyword(s):  
Density Functional ◽  
Computational Study ◽  
Basis Sets ◽  
Mulliken Charge ◽  
Monoclinic Space Group ◽  
X Ray Diffraction ◽  
Dft Methods ◽  
X Ray ◽  
X Ray Crystallography ◽  
The Density Functional Theory

The paper presents a combined experimental and computational study of hexa(1-vinylimidazole)Ni(II) perchlorate complex. The complex was prepared in the laboratory and crystallized in the monoclinic space group P21/n with a=8.442(5), b=13.686(8), c=16.041(9) Å, α=γ=90, β=96.638(5), and Z=1. The complex has been characterized structurally (by single-crystal X-Ray diffraction) and its molecular structure in the ground state has been calculated using the density functional theory (DFT) methods with 6-31G(d) and LanL2DZ basis sets. Thermal behaviour and stability of the complex were studied by TGA/DTA analyses. Besides, the nonlinear optical effects (NLO), molecular electrostatic potential (MEP), frontier molecular orbitals (FMO), and the Mulliken charge distribution were investigated theoretically.

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