Modeling the Physical Properties of ZnO Nanoparticles with Selective Hydrogen Using DFT

2020 ◽  
pp. 2150011
Author(s):  
Bilal K. Al-Rawi ◽  
Safaa M. H. Aljanabi
Keyword(s):  
Bond Length ◽  
Vibration Frequency ◽  
Zno Nanoparticles ◽  
Density Functional ◽  
Energy Gap ◽  
Frequency Function ◽  
Functional Theory ◽  
Nanoparticle Surface ◽  
Homo And Lumo ◽  
The Impact

The impact of hydrogen on the conductivity and vibration for zinc oxide (ZnO) nanoparticles had implicated for nanoscale optoelectronic units. Infrared reflectance spectra for ZnO hydrogen-annealed nanoparticles were calculated at incidence. The theory of density functional theory is applied to the reflectance model and absorption spectra. There is an agreement between both the model suggesting that the nanoparticles have inhomogeneous carriers’ concentrations and the experimental results. A significant decrease in carrier concentration resulted from exposure to oxygen for several hours, according to the adsorption on the nanoparticle surface of negative oxygen molecules. Also, the density of states in deferent wurtzoid’s size has been studied. The experimental energy gap values of bulk ZnO, HOMO and LUMO levels as a function of the total Zn and O atoms number in ZnOH diamondoids were determined, as well as the bond length in deferent wurtzoid’s size where the experimental ZnO bond length at 1.9767 Å has been calculated. The tetrahedral angles in deferent wurtzoid’s size were studied, deferent wurtzoid’s size Reduced mass as a vibration frequency function and force constant as a function of vibrational frequency in deferent wurtzoid’s size were determined. A good result for infrared as a vibration frequency function in deferent wurtzoid’s size has been found, as well as Raman as a vibration frequency function in deferent wurtzoid’s size.

Molecular Investigations of the Newly Synthesized Azomethines as Antioxidants: Theoretical and Experimental Studies

2019 ◽  
Vol 19 (6) ◽  
pp. 419-433 ◽  
Author(s):  
Siyamak Shahab ◽  
Masoome Sheikhi ◽  
Liudmila Filippovich ◽  
Evgenij Dikusar ◽  
Anhelina Pazniak ◽  
...  
Keyword(s):  
Density Functional ◽  
Energy Gap ◽  
Experimental Studies ◽  
Antioxidant Property ◽  
Nbo Analysis ◽  
Antioxidant Potential ◽  
Functional Theory ◽  
Homo And Lumo ◽  
Intramolecular Hydrogen ◽  
Activity Mechanism

: In this study, the antioxidant property of new synthesized azomethins has been investigated as theoretical and experimental. Methods and Results: Density functional theory (DFT) was employed to investigate the Bond Dissociation Enthalpy (BDE), Mulliken Charges, NBO analysis, Ionization Potential (IP), Electron Affinities (EA), HOMO and LUMO energies, Hardness (η), Softness (S), Electronegativity (µ), Electrophilic Index (ω), Electron Donating Power (ω-), Electron Accepting Power (ω+) and Energy Gap (Eg) in order to deduce scavenging action of the two new synthesized azomethines (FD-1 and FD-2). Spin density calculations and NBO analysis were also carried out to understand the antioxidant activity mechanism. Comparison of BDE of FD-1 and FD-2 indicate the weal antioxidant potential of these structures. Conclusion: FD-1 and FD-2 have very high antioxidant potential due to the planarity and formation of intramolecular hydrogen bonds.

scholarly journals Spectroscopic and Electrochemical Investigations of New 5-oxo-2- Phenyloxazol-4(5H)-ylidene Based Triazine Derivatives

2019 ◽  
Vol 1 (1) ◽  
Keyword(s):  
Density Functional ◽  
Energy Gap ◽  
Electronic Absorption Spectra ◽  
Spectroscopic Properties ◽  
Functional Theory ◽  
Structural Framework ◽  
Triazine Derivatives ◽  
Homo And Lumo ◽  
Cyclic Voltammetry Analysis ◽  
Oxazolone Ring

The present study reports the two step synthesis of a novel oxazolone derivative, 4-((4,6-bis(4-((Z)-(5-oxo-2-phenyloxazol-4(5H)-ylidene) methyl)phenoxy)-1,3,5-triazin-2-yl) oxy) benzaldehyde (CBOZ (5)), containing two oxazolone ring substituted with central triazine nucleus in their structural framework. The structural and spectroscopic properties of synthesized CBOZ (5) were characterized by FTIR, 1HNMR, 13CNMR, and mass spectroscopic analysis. The UV-Vis absorption of CBOZ (5) showed a single absorption band at ~370 nm due to π-π* transition with the estimated energy gap of ~3.02 eV. Cyclic voltammetry analysis revealed that the synthesized CBOZ (5) obtained the HOMO and LUMO values of -5.87 eV and-2.85 eV, respectively. Density functional theory (DFT) studies were carried out to predict the electronic absorption spectra of CBOZ (5) and the obtained values were in excellent agreement with the experimental results.

DFT Study on Geometric and Electronic Structures Properties of Dye Sensitizers

2015 ◽  
Vol 748 ◽  
pp. 197-200
Author(s):  
Mei Juan Cao ◽  
Zhi Cheng Sun ◽  
Lu Hai Li ◽  
Yuan Bin She ◽  
Zuo Lin Yang ◽  
...  
Keyword(s):  
Electronic Transport ◽  
Electronic Structures ◽  
Energy Barrier ◽  
Density Functional ◽  
Energy Gap ◽  
Frontier Molecular Orbital ◽  
Central Metal ◽  
Functional Theory ◽  
Homo And Lumo ◽  
Porphyrin Core

A series of porphyrin sensitizers with different central metal ions (PMn, PFe, PCo, PNi, PCu, and PZn) have been studied based on density functional theory (DFT). The geometric structure of the dyes was optimized and the frontier molecular orbital were calculated. The result shows that the LUMO levels of PFe, PNi and PZn were much lower than that of PMn, PCo and PCu, which suggest a lower energy barrier for electron transfer from the donor to the acceptor tunneling. Furthermore, the energy gap of HOMO and LUMO for PFe was only 0.81 eV, it indicates a significant red shift of the absorption spectrum. The LUMO of PMn, PNi, PCu and PZn were mainly decocalized on the porphyrin core and the bridge moiety, which was beneficial to electronic transport.

scholarly journals (E)-1-(Benzo[d][1,3]dioxol-5-yl)-3-([2,2′-bithiophen]-5-yl)prop-2-en-1-one: crystal structure, UV–Vis analysis and theoretical studies of a new π-conjugated chalcone

2019 ◽  
Vol 75 (5) ◽  
pp. 632-637
Author(s):  
Ainizatul Husna Anizaim ◽  
Muhamad Fikri Zaini ◽  
Muhammad Adlan Laruna ◽  
Ibrahim Abdul Razak ◽  
Suhana Arshad
Keyword(s):  
Density Functional ◽  
Energy Gap ◽  
Weak Interactions ◽  
Basis Set ◽  
Molecular Orbital Calculations ◽  
Functional Theory ◽  
Compound C ◽  
Homo And Lumo ◽  
Experimental Values ◽  
Homo Lumo

In the title compound, C18H12O3S2, synthesized by the Claisen–Schmidt condensation method, the essentially planar chalcone unit adopts an s-cis configuration with respect to the carbonyl group within the ethylenic bridge. In the crystal, weak C—H...π interactions connect the molecules into zigzag chains along the b-axis direction. The molecular structure was optimized geometrically using Density Functional Theory (DFT) calculations at the B3LYP/6–311 G++(d,p) basis set level and compared with the experimental values. Molecular orbital calculations providing electron-density plots of HOMO and LUMO molecular orbitals and molecular electrostatic potentials (MEP) were also computed both with the DFT/B3LYP/6–311 G++(d,p) basis set. The experimental energy gap is 3.18 eV, whereas the theoretical HOMO–LUMO energy gap value is 2.73 eV. Hirshfeld surface analysis was used to further investigate the weak interactions present.

Exploring the impact of hydrostatic pressure on the structural, electronic and mechanical properties of ZrNiPb half-Heusler alloy: A DFT approach

2018 ◽  
Vol 32 (23) ◽  
pp. 1850248
Author(s):  
M. I. Babalola ◽  
B. I. Adetunji ◽  
B. E. Iyorzor ◽  
A. Yaya
Keyword(s):  
Mechanical Properties ◽  
Heusler Alloy ◽  
Poisson’S Ratio ◽  
Density Functional ◽  
Energy Gap ◽  
Poisson's Ratio ◽  
Generalized Gradient ◽  
Functional Theory ◽  
The Density Functional Theory ◽  
The Impact

The structural, electronic, elastic and mechanical properties of ZrNiPb half-Heusler alloy under pressure ranging from 0 to 25 GPa have been studied using the density functional theory within the generalized gradient approximation (GGA). The results of ambient condition were in good agreement with the available theoretical and experimental data. Our electronic structure and density of state results show that ZrNiPb is an indirect bandgap semiconductor half-Heusler alloy with a narrow energy gap of 0.375 eV. Based on the calculated elastic constants (C[Formula: see text], C[Formula: see text] and C[Formula: see text]), Young’s modulus (E), Poisson’s ratio ([Formula: see text]), Shear modulus (G), Zener anisotropy factor (A) and brittle-ductile behaviors under pressure have been discussed. The calculated Poisson’s ratio shows that ZrNiPb undergoes a relatively small volume change during uniaxial deformation. We show that the chemical bonds in ZrNiPb are stronger due to the high value of C[Formula: see text].

Dissymmetric Bay-Functionalized Perylenediimides

Synlett ◽  
2018 ◽  
Vol 29 (13) ◽  
pp. 1693-1699 ◽  
Author(s):  
Prabhpreet Singh ◽  
Kapil Kumar ◽  
Gaurav Bhargava ◽  
Subodh Kumar
Keyword(s):  
Density Functional Theory ◽  
Density Functional ◽  
Energy Gap ◽  
Twist Angle ◽  
Density Functional Theory Calculations ◽  
Two Dimensional ◽  
Functional Theory ◽  
Donor Acceptor ◽  
Homo And Lumo ◽  
Transfer Properties

We report the synthesis of perylenediimide (PDI)-based ­donor–acceptor hybrids through dissymmetric bay functionalization of PDIs. The dissymmetric bay-functionalized di- and trisubstituted PDIs were characterized by using one- and two-dimensional NMR spectroscopy. Density functional theory calculations revealed (i) an energy gap between the HOMO and LUMO in the range 2.14–2.34 eV, beneficial for charge-transfer properties; and (ii) a twist angle between the two naphthalene units in the range 17–26°, which might be beneficial for disruption of co-facial stacking of the PDI.

Spectroscopic investigations and DFT studies of synthesized 4-acetamidophenyl 3,4,5-trimethoxybenzoate and 4-acetyl phenyl 3,4,5-trimethoxybenzoate a novel conjugate of gallic acid

2020 ◽  
Vol 17 ◽  
Author(s):  
Sangeeta Srivastava ◽  
Nadeem Ahmad Ansari ◽  
Sadaf Aleem
Keyword(s):  
Gallic Acid ◽  
Density Functional ◽  
Energy Gap ◽  
Basis Set ◽  
Major Constituent ◽  
Orbital Energy ◽  
Reactivity Descriptors ◽  
Homo And Lumo ◽  
Electrophilic Reactivity ◽  
Global And Local

: Gallic acid is abundantly found in amla (Phyllanthus emblica), a deciduous of the family phyllanthaceae. Gallic acid, the major constituent of the plant was methylated to 3,4,5 trimethoxy gallic acid, which then underwent steglich esterification first with paracetamol and then with 4-hydroxy acetophenone to yield 4-acetamidophenyl 3,4,5-trimethoxybenzoate and 4-acetyl phenyl 3,4,5-trimethoxybenzoate “respectively”. 1H NMR, 13C NMR, UV, FT-IR and mass spectroscopy were used to characterize the synthesized compounds. Density functional theory (B3YLP) using 6-31G (d,p) basis set have been used for quantum chemical calculations. AIM (Atom in molecule) approach depicted weak molecular interactions within the molecules whereas the reactive site and reactivity within the molecule were examined by global and local reactivity descriptors. The HOMO and LUMO energies and frontier orbital energy gap were calculated by time dependant DFT approach using IEFPCM model. Small value for HOMO–LUMO energy gap indicated that easier charge transfer occurs within compound 4. The nucleophilic and electrophilic reactivity were determined by MEP (molecular electrostatic potential) experiment. Polarizability, dipole moment, and first hyperpolarizability values were calculated to depict the NLO (nonlinear optical) property of both the synthesized compounds. The antimicrobial activity was also carried out and broad spectrum antibacterial activity against several strains of bacteria and certain unicellular fungi were exhibited by synthesized compound 3.

scholarly journals Exo⇔Endo Isomerism, MEP/DFT, XRD/HSA-Interactions of 2,5-Dimethoxybenzaldehyde: Thermal, 1BNA-Docking, Optical, and TD-DFT Studies

Molecules ◽  
2020 ◽  
Vol 25 (24) ◽  
pp. 5970
Author(s):  
Nabil Al-Zaqri ◽  
Mohammed Suleiman ◽  
Anas Al-Ali ◽  
Khaled Alkanad ◽  
Karthik Kumara ◽  
...  
Keyword(s):  
Density Functional ◽  
Energy Gap ◽  
Structural Parameters ◽  
Population Analysis ◽  
Xrd Analysis ◽  
X Ray Diffraction ◽  
Optical Energy Gap ◽  
Functional Theory ◽  
Reactivity Descriptors ◽  
Td Dft

The exo⇔endo isomerization of 2,5-dimethoxybenzaldehyde was theoretically studied by density functional theory (DFT) to examine its favored conformers via sp2–sp2 single rotation. Both isomers were docked against 1BNA DNA to elucidate their binding ability, and the DFT-computed structural parameters results were matched with the X-ray diffraction (XRD) crystallographic parameters. XRD analysis showed that the exo-isomer was structurally favored and was also considered as the kinetically preferred isomer, while several hydrogen-bonding interactions detected in the crystal lattice by XRD were in good agreement with the Hirshfeld surface analysis calculations. The molecular electrostatic potential, Mulliken and natural population analysis charges, frontier molecular orbitals (HOMO/LUMO), and global reactivity descriptors quantum parameters were also determined at the B3LYP/6-311G(d,p) level of theory. The computed electronic calculations, i.e., TD-SCF/DFT, B3LYP-IR, NMR-DB, and GIAO-NMR, were compared to the experimental UV–Vis., optical energy gap, FTIR, and 1H-NMR, respectively. The thermal behavior of 2,5-dimethoxybenzaldehyde was also evaluated in an open atmosphere by a thermogravimetric–derivative thermogravimetric analysis, indicating its stability up to 95 °C.

scholarly journals An Evaluation of the Impact of the Amount of Potassium Hydroxide on the Porous Structure Development of Activated Carbons

Materials ◽  
2021 ◽  
Vol 14 (8) ◽  
pp. 2045
Author(s):  
Mirosław Kwiatkowski ◽  
Elżbieta Broniek ◽  
Vanessa Fierro ◽  
Alain Celzard
Keyword(s):  
Density Functional Theory ◽  
Porous Structure ◽  
Potassium Hydroxide ◽  
Density Functional ◽  
Activated Carbons ◽  
Chemical Activation ◽  
Appropriate Technology ◽  
Functional Theory ◽  
Homogeneous Surface ◽  
The Impact

This paper presents the results of an evaluation of the impact of the amount of potassium hydroxide on the obtained porous structure of the activated carbons derived from the shells of pistachios, hazelnuts, and pecans by carbonization and subsequent chemical activation with potassium hydroxide by different adsorption methods: Brunauer–Emmett–Teller, Dubinin–Raduskevich, the new numerical clustering-based adsorption analysis, Quenched Solid Density Functional Theory, and 2D-Non-linear Density Functional Theory for Heterogeneous Surfaces, applied to nitrogen adsorption isotherms at −196 °C. Based on the conducted research, a significant potential for the production of activated carbons from waste materials, such as nut shells, has been demonstrated. All the activated carbons obtained in the present study at the activator/char mass ratio R = 4 exhibited the most developed porous structure, and thus very good adsorption properties. However, activated carbons obtained from pecan shells deserve special attention, as they were characterized by the most homogeneous surface among all the samples analyzed, i.e., by a very desirable feature in most adsorption processes. The paper demonstrates the necessity of using different methods to analyze the porous structure of activated carbons in order to obtain a complete picture of the studied texture. This is because only a full spectrum of information allows for correctly selecting the appropriate technology and conditions for the production of activated carbons dedicated to specific industrial applications. As shown in this work, relying only on the simplest methods of adsorption isotherm analysis can lead to erroneous conclusions due to lack of complete information on the analyzed porous structure. This work thus also explains how and why the usual characterizations of the porous structure of activated carbons derived from lignocellulosic biomass should not be taken at face value. On the contrary, it is advisable to cross reference several models to get a precise idea of the adsorbent properties of these materials, and therefore to propose the most suitable production technology, as well as the conditions of the preparation process.

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