scholarly journals Diaryl Sulfide Derivatives as Potential Iron Corrosion Inhibitors: A Computational Study

Molecules ◽  
2021 ◽  
Vol 26 (20) ◽  
pp. 6312
Author(s):  
Morad M. El-Hendawy ◽  
Asmaa M. Kamel ◽  
Mahmoud M. A. Mohamed ◽  
Rabah Boukherroub ◽  
Jacek Ryl ◽  
...  
Keyword(s):  
Density Functional ◽  
Corrosion Inhibitors ◽  
Computational Study ◽  
Structural Factors ◽  
Iron Corrosion ◽  
Quantum Chemical Descriptors ◽  
Diaminodiphenyl Sulfone ◽  
The Density Functional Theory ◽  
Mc Simulation ◽  
Diaryl Sulfide

The present work aimed to assess six diaryl sulfide derivatives as potential corrosion inhibitors. These derivatives were compared with dapsone (4,4′-diaminodiphenyl sulfone), a common leprosy antibiotic that has been shown to resist the corrosion of mild steel in acidic media with a corrosion efficiency exceeding 90%. Since all the studied compounds possess a common molecular backbone (diphenyl sulfide), dapsone was taken as the reference compound to evaluate the efficiency of the remainder. In this respect, two structural factors were examined, namely, (i) the effect of replacement of the S-atom of diaryl sulfide by SO or SO2 group, (ii) the effect of the introduction of an electron-withdrawing or an electron-donating group in the aryl moiety. Two computational chemical approaches were used to achieve the objectives: the density functional theory (DFT) and the Monto Carlo (MC) simulation. First, B3LYP/6-311+G(d,p) model chemistry was employed to calculate quantum chemical descriptors of the studied molecules and their geometric and electronic structures. Additionally, the mode of adsorption of the tested molecules was investigated using MC simulation. In general, the adsorption process was favorable for molecules with a lower dipole moment. Based on the adsorption energy results, five diaryl sulfide derivatives are expected to act as better corrosion inhibitors than dapsone.

scholarly journals Application of β-Phosphorylated Nitroethenes in [3+2] Cycloaddition Reactions Involving Benzonitrile N-Oxide in the Light of a DFT Computational Study

Organics ◽  
2021 ◽  
Vol 2 (1) ◽  
pp. 26-37
Author(s):  
Karolina Zawadzińska ◽  
Karolina Kula
Keyword(s):  
Density Functional ◽  
Reaction Path ◽  
Computational Study ◽  
Cyano Group ◽  
Cycloaddition Reactions ◽  
Functional Theory ◽  
The Density Functional Theory ◽  
Reaction Channels ◽  
One Step ◽  
Step Mechanism

The regiochemistry of [3+2] cycloaddition (32CA) processes between benzonitrile N-oxide 1 and β-phosphorylated analogues of nitroethenes 2a–c has been studied using the Density Functional Theory (DFT) at the M062X/6-31+G(d) theory level. The obtained results of reactivity indices show that benzonitrile N-oxide 1 can be classified both as a moderate electrophile and moderate nucleophile, while β-phosphorylated analogues of nitroethenes 2a–c can be classified as strong electrophiles and marginal nucleophiles. Moreover, the analysis of CDFT shows that for [3+2] cycloadditions with the participation of β-phosphorylatednitroethene 2a and β-phosphorylated α-cyanonitroethene 2b, the more favored reaction path forms 4-nitro-substituted Δ2-isoxazolines 3a–b, while for a reaction with β-phosphorylated β-cyanonitroethene 2c, the more favored path forms 5-nitro-substituted Δ2-isoxazoline 4c. This is due to the presence of a cyano group in the alkene. The CDFT study correlates well with the analysis of the kinetic description of the considered reaction channels. Moreover, DFT calculations have proven the clearly polar nature of all analyzed [3+2] cycloaddition reactions according to the polar one-step mechanism.

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.

Mechanistic insight into the selective trans-1,4-polymerization of butadiene by terpyridine–iron(II) complexes — A computational study

2009 ◽  
Vol 87 (10) ◽  
pp. 1392-1405 ◽  
Author(s):  
Sven Tobisch
Keyword(s):  
Density Functional ◽  
Computational Study ◽  
Dft Method ◽  
Chain Growth ◽  
Functional Theory ◽  
The Density Functional Theory ◽  
Insertion Mechanism ◽  
Trans Regulation ◽  
Insight Into

The density functional theory (DFT) method has been employed to unravel mechanistic intricacies of the 1,4-polymerization of 1,3-butadiene mediated by the [(η3-RC3H4)FeII(C15H11N3)(η2-C4H6)]+ terpyridine–iron(II) active catalyst species. The π-allyl-insertion mechanism is operative for chain growth, whilst the alternative σ-allyl-insertion mechanism has been explicitly demonstrated as being inoperable. This study elucidates the mechanism of cis–trans regulation and unveils the factors that govern the observed high trans-1,4 stereoselectivity, in particular, the discriminative role of allylic isomerization. An atactic trans-1,4-polydiene is expected from polymerization of a terminally monosubstituted butadiene, the experimental results of which have not been reported thus far.

scholarly journals Computational Study on Substituteds-Triazine Derivatives as Energetic Materials

2012 ◽  
Vol 9 (2) ◽  
pp. 583-592 ◽  
Author(s):  
Vikas D. Ghule ◽  
S. Radhakrishnan ◽  
Pandurang M. Jadhav ◽  
Surya P. Tewari
Keyword(s):  
Thermal Stability ◽  
Energetic Materials ◽  
Density Functional ◽  
Crystal Packing ◽  
Computational Study ◽  
Heats Of Formation ◽  
Dissociation Energies ◽  
The Density Functional Theory ◽  
Triazine Derivatives ◽  
Derivatives Of

s-Triazine is the essential candidate of many energetic compounds due to its high nitrogen content, enthalpy of formation and thermal stability. The present study explores s-triazine derivatives in which different -NO2, -NH2and -N3substituted azoles are attached to the triazine ring via C-N linkage. The density functional theory is used to predict geometries, heats of formation and other energetic properties. Among the designed compounds, -N3derivatives show very high heats of formation. The densities for designed compounds were predicted by using the crystal packing calculations. Introduction of -NO2group improves density as compared to -NH2and -N3, their order of increasing density can be given as NO2>N3>NH2. Analysis of the bond dissociation energies for C-NO2, C-NH2and C-N3bonds indicates that substitutions of the -N3and -NH2group are favorable for enhancing the thermal stability ofs-triazine derivatives. The nitro and azido derivatives of triazine are found to be promising candidates for the synthetic studies.

scholarly journals Structural characterization of kaempferol: a spectroscopic and computational study

2019 ◽  
Vol 38 (1) ◽  
pp. 49 ◽  
Author(s):  
Dejan Milenković ◽  
Jasmina M Dimitrić Marković ◽  
Dušan Dimić ◽  
Svetlana Jeremić ◽  
Dragan Amić ◽  
...  
Keyword(s):  
Density Functional ◽  
Computational Study ◽  
Chemical Shifts ◽  
Absolute Error ◽  
Nbo Analysis ◽  
Basis Set ◽  
Functional Theory ◽  
The Density Functional Theory ◽  
Spectroscopic Characteristics

Calculations based on the density functional theory, with the B3LYP functional and the 6-311++G(d,p) basis set, were performed with the aim of confirming the molecular structure and spectroscopic characteristics of kaempferol, a naturally occurring flavonoid molecule. The electronic structure of kaempferol was examined using NBO analysis. The assigning of the experimentally obtained IR and Raman spectra was performed after the best-fit-based comparison with theoretical spectra. The 13C and 1H NMR experimental spectra were related to the theoretically obtained values of the chemical shifts determined by the GIAO method. The correlation coefficient and the average absolute error values proved B3LYP-D3 to be an adequate method in describing the NMR parameters of kaempferol. Molecular docking analysis was carried out in order to identify the potency of inhibition of the title molecule against human procalcitonin. The inhibition activity was obtained for 10 conformations of ligand inside the protein.

Tritium adsorption in the lithium vacancy of Li2ZrO3: A first principles study

2018 ◽  
Vol 29 (10) ◽  
pp. 1850103
Author(s):  
Kun Li ◽  
Wen Yang ◽  
Wei-Hua Wang ◽  
Yong-Tang Li
Keyword(s):  
Density Functional ◽  
Computational Study ◽  
Fundamental Problem ◽  
Density Functional Theory Calculations ◽  
Intrinsic Defect ◽  
Release Process ◽  
Functional Theory ◽  
Theoretical Support ◽  
The Density Functional Theory ◽  
Lithium Vacancy

Tritium adsorption in the irradiation defects of the Li2ZrO3 is a fundamental problem to understand the tritium behavior during the release process. A comprehensive computational study of tritium/helium adsorption in the lithium vacancy of bulk Li2ZrO3 is presented by the density functional theory calculations. The most stable tritium adsorption position has been found and it is determined by the neighboring lithium–oxygen interactions. The results reveal that the intrinsic defect is the lithium vacancy with one electron and it transforms to be the neutral state after a tritium atom is adsorbed. Moreover, helium is adsorbed almost in the center of lithium vacancy without bonding with surrounding oxygen atoms, which could diffuse easily in the bulk Li2ZrO3. Therefore, we predict that the intrinsic Li vacancy tends to adsorb a positive ion T[Formula: see text] other than a neutral T atom. Our results provide theoretical support to understand the T behavior in the Li2ZrO3 crystal.

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.

Computational study of the optical properties of ZnS nanoparticles

2015 ◽  
Vol 1738 ◽  
Author(s):  
M. M. Sigalas
Keyword(s):  
Density Functional Theory ◽  
Optical Properties ◽  
Density Functional ◽  
Computational Study ◽  
Time Dependent ◽  
Generalized Gradient ◽  
Zns Nanoparticles ◽  
Functional Theory ◽  
Generalized Gradient Approximation ◽  
The Density Functional Theory

ABSTRACTUsing the density functional theory (DFT) and time dependent DFT, within the generalized gradient approximation (GGA), the electronic and optical properties of stoichiometric (ZnS)n nanoparticles (NP) were calculated. The dependence of the gap on the size (n) of the nanoparticle will be presented. The effect of replacing S atoms with P, Se or Te atoms in the (ZnS)n nanoparticles and its influence in the gap will be also shown.

Computational study on the mechanism of the three-component reaction of dimethylacetylene dicarboxylate and triphenylphosphine with 2-acetylbutyrolactone

2015 ◽  
Vol 93 (6) ◽  
pp. 666-672 ◽  
Author(s):  
Mina Haghdadi ◽  
Sakineh Asghari ◽  
Samaneh Ramezani
Keyword(s):  
Density Functional ◽  
Wittig Reaction ◽  
Computational Study ◽  
Density Functional Theory Method ◽  
Functional Theory ◽  
Phosphorus Ylide ◽  
Intramolecular Wittig Reaction ◽  
Ring Opening Reaction ◽  
The Density Functional Theory ◽  
Three Component Reaction

The molecular mechanism of the three-component reaction of triphenylphosphine, dialkyl acetylene dicarboxylate, and 2-acetylbutyrolactone to synthesize the stabilized phosphorus ylide and 1,3-butadiene derivative via the intramolecular Wittig reaction has been investigated using the density functional theory method at the B3LYP/6-31G level of theory. Two possible reaction pathways have been characterized in detail to form the cyclobutene intermediate and in the next step; the cyclobutene intermediate undergoes the conrotatory ring-opening reaction to produce the 1,3-butadiene derivative along two possible pathways. The calculated results indicate that two pathways (pathways II and II-a) are the most energy favorable among all of the pathways, so they occur more than do the others. Moreover, the phosphorus ylide is more stable than the corresponding 1,3-butadiene, demonstrating that the intramolecular Wittig reaction could not easily occur at room temperature, which is in agreement with the experimental results.

Computational study on zinc porphyrin analogs for use in dye-sensitized solar cells

2014 ◽  
Vol 18 (05) ◽  
pp. 406-415 ◽  
Author(s):  
Hong-Qiang Xia ◽  
Jie Chen ◽  
Fu-Quan Bai ◽  
Hong-Xing Zhang
Keyword(s):  
Absorption Spectra ◽  
Density Functional ◽  
Computational Study ◽  
Dye Sensitized Solar Cells ◽  
Absorption Enhancement ◽  
Zinc Porphyrin ◽  
The Density Functional Theory ◽  
Td Dft ◽  
Sensitized Solar Cells ◽  
Porphyrin Analogs

The density functional theory (DFT) and time-dependent DFT (TD-DFT) approaches have been applied to obtain the optimized geometries, electronic structures, molecular orbitals and absorption spectra of a series of meso-substituted zinc porphyrin analogs with phenyl and thiophene groups as the π bridging unit and cyanoacrylic acid as the acceptor unit. The results showed that the introduction of thiophene group increases the orbital splitting and changes the absorption spectra properties significantly. It is indicated that when there is only one thiophene group included in the π bridge, the oscillator strength of B absorption band is much stronger. The increasing length of thiophene chain just changes the scope of specific absorption enhancement. The effect of attaching an additional electron-donating group diphenylamine instead of phenyl to the porphyrin core also has been shown. It is found that the diphenylamine group reduces the band gap, and leads to facile intramolecular charge transfer from diphenylamine and porphyrin ring unit to acceptor unit. These kinds of zinc porphyrin analogs have the LUMO energy close to the conduction band of TiO 2 and more red-shifted absorption spectrum compared with phenyl substituted analogs.

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