Effect of external electric field on the adsorption of ethylene oxide on pristine and Al-doped coronenes: A DFT study

2018 ◽  
Vol 17 (05) ◽  
pp. 1850032 ◽  
Author(s):  
Tooba Afshari ◽  
Mohsen Mohsennia
Keyword(s):  
Ethylene Oxide ◽  
Electric Fields ◽  
Electronic Structures ◽  
Density Functional ◽  
Molecular Electrostatic Potential ◽  
Band Gap Energy ◽  
Basis Set ◽  
Mulliken Charge ◽  
Functional Theory ◽  
Energy Formula

The adsorption interactions between ethylene oxide (EO) molecule and pristine and aluminum-doped coronene (Al-coronene) were studied in the presence and absence of perpendicular external electric fields (EFs) with strengths [Formula: see text], [Formula: see text] and [Formula: see text] a.u. using density functional theory (DFT) calculations. The geometry optimizations and adsorption calculations were carried out by employing 6-31[Formula: see text]G** basis set. The changes in geometric and electronic structures after the adsorption were investigated to characterize the sensitivity of pristine and Al-coronene toward EO molecules. For all the studied systems, adsorption energies ([Formula: see text], band gap energy ([Formula: see text], Mulliken charge transfer, molecular electrostatic potential (MEP) and density of electron state (DOS) were calculated and discussed. According to the obtained results, the high impact of the applied EFs on the adsorption characteristics of EO molecules on the pristine and Al-doped coronenes showed that applying EF is a good strategy for enhancing the EO adsorption capability of the pristine and Al-doped coronenes, improving the potential application of coronene-based sensors for detection of EO in trace amounts.

scholarly journals Transition metals doped ZnO nanocluster for ethylene oxide detection: A DFT study

2019 ◽  
Vol 42 (1) ◽  
pp. 113-120 ◽  
Author(s):  
Tooba Afshari ◽  
Mohsen Mohsennia
Keyword(s):  
Transition Metals ◽  
Ethylene Oxide ◽  
Density Functional ◽  
Band Gap Energy ◽  
Mulliken Charge ◽  
Electronic Interaction ◽  
Functional Theory ◽  
Potential Applicability ◽  
Gas Molecules ◽  
Doped Zno

Abstract Density functional theory (DFT) studies at B3LYP/6-31G (d) (Becke, 3-parameter, Lee-Yang-Parr) level were performed to evaluate adsorption interactions between ethylene oxide (EO) molecule, and pristine and transition metals (TM) (i.e., Sc, Ti, V, Cr, Mn, Fe, Co, Ni, and Cu) doped ZnO nanocluster (TM-doped Zn12O12). The adsorption energy (Ead), band gap energy (Eg), Mulliken charge transfer (QT) and molecular electrostatic potential (MEP) were calculated to examine the sensitivity of the Zn12O12 and its TM-doped forms toward EO detection. It was found that in contrast to the pristine Zn12O12, the electronic properties of TM-doped Zn12O12 were sharply sensitive to the presence of EO gas molecules. The results revealed that among the studied TM-doped Zn12O12, Cr- and V-doped Zn12O12 have great potential applicability as EO sensor, due to their highest Eg change (ΔEg) values, after the EO adsorption. Moreover, the density of state (DOS) calculations confirmed that strong electronic interaction between Cr- and V-doped Zn12O12 and EO molecules can makes them interesting empirical candidate for detection and adsorptive removal of EO gas molecules.

scholarly journals Electronic structures and photovoltaic properties of a novel phthalocyanine and titanium dioxide phthalocyanine for dye sensitized-solar cells

2021 ◽  
Vol 6 (3) ◽  
pp. 107-115
Author(s):  
Fares A. Yasseen ◽  
Faeq A. Al-Temimei
Keyword(s):  
Density Functional Theory ◽  
Solar Cells ◽  
Electronic Structures ◽  
Density Functional ◽  
Energy Gap ◽  
Dye Sensitized Solar Cells ◽  
Solar Spectrum ◽  
Electron Injection ◽  
Basis Set ◽  
Functional Theory

In the present work, geometries, electronic structures, photovoltaic and optical properties have been carried out on a series of structures formation of phthalocyanine and Titanylphthalocyanine dyes, which are replaced by several subgroup. A density functional theory (DFT) approach together with hybrid function (B3LYP) at SDD basis set was used for the ground state properties in the gas phase. The time-dependent density functional theory (TD-DFT)/ B3LYP was used to investigate the excitation properties of new dyes and analyzed the trends in their optical and redox characteristics. Theoretical principles of HOMO and LUMO energy levels of dyes is requisite in analyzing organic solar cells, thus, HOMO, LUMO levels, open circuit voltage, energy gap, light harvestings efficiency, electron regeneration and electron injection have been calculated and discussed. The outcome of the efficiency, the considered dyes explain absorption energy and wavelength properties that correspond to the solar spectrum requirements. According to results, all the considered materials have a good property and possibility of electron injection procedure from the dyes to conduction band of TiO2, PC60BM or PC60BM. As a result, the molecular changes affect the electronic properties of dye molecules for solar cells. Also, a study of new dyes sensitizers showed that designed materials will be excellent sensitizers. Theoretical designing will prae a way for experimentalists to synthesize the efficient sensitizers for solar cells clearer.

scholarly journals How Accurate Are Static Polarizability Predictions from Density Functional Theory? An Assessment over 132 Species at Equilibrium Geometry

2018 ◽  
Author(s):  
Diptarka Hait ◽  
Martin Head-Gordon
Keyword(s):  
Electric Fields ◽  
Density Functional ◽  
Basis Set ◽  
Equilibrium Geometry ◽  
Density Functionals ◽  
Functional Theory ◽  
First Response ◽  
Complete Basis Set ◽  
Complete Basis Set Limit ◽  
Hybrid Functionals

Static polarizabilities are the first response of the electron density to electric fields, and are therefore important for predicting intermolecular and molecule-field interactions. They also offer a global measure of the accuracy of the treatment of excited states by density functionals in a formally exact manner. We have developed a database of benchmark static polarizabilities for 132 small species at equilibrium geometry, using coupled cluster theory through triple excitations (extrapolated to the complete basis set limit), for the purpose of developing and assessing density functionals. The performance of 60 popular and recent functionals are also assessed, which indicates that double hybrid functionals perform the best, having RMS errors in the range of 2.5-3.8% . Many hybrid functionals also give quite reasonable estimates with 4-5% RMSE. A few meta-GGAs like mBEEF and MVS yield performance comparable to hybrids, indicating potential for improved excited state predictions relative to typical local functionals. Some recent functionals however are found to be prone to catastrophic failure (possibly as a consequence of overparameterization), indicating a need for caution in applying these.

scholarly journals Theoretical Evaluation on The Interaction Between Triglycerides and Methylxanthines Using Density Functional Theory B3LYP/6-31G(d,p) and Molecular Electrostatic Potential

2020 ◽  
Vol 33 (1) ◽  
pp. 171-178
Author(s):  
N.F.M. Azmi ◽  
R. Ali ◽  
A.A. Azmi ◽  
M.Z.H. Rozaini ◽  
K.H.K. Bulat ◽  
...  
Keyword(s):  
Density Functional Theory ◽  
Hydrogen Bond ◽  
Electrostatic Potential ◽  
Density Functional ◽  
Molecular Electrostatic Potential ◽  
Basis Set ◽  
Individual Species ◽  
Interaction Energies ◽  
Binding Interaction ◽  
Functional Theory

The binding, interaction and distortion energies between the main triglycerides, palmitic-oleic-stearic (POS) in cocoa butter versus palmitic-oleic-palmitic (POP) in refined, bleached and deodorized (RBD) palm oil with cocoa′s methylxanthines (caffeine, theobromine, and theophylline) during the production of chocolate were theoretically studied and reported. The quantum mechanical software package of Gaussian09 at the theoretical level of density functional theory B3LYP/6-31G(d,p) was employed for all calculations, optimization, and basis set superposition errors (BSSE). Geometry optimizations were carried out to the minimum potential energy of individual species and binary complexes formed between the triglycerides, methylxanthines and polyphenols. The interaction energies for the optimized complexes were then corrected for the BSSE using the counterpoise method of Boys and Bernardi. The results revealed that the binding energy and interaction energy between methylxanthine components in cocoa powder with triglycerides were almost of the same magnitude (13.6-14.5 and 3.4-3.7 kJ/mol, respectively), except for the binary complex of POS-caffeine (25.1 and 10.7 kJ/mol, respectively). Based on the molecular geometry results, the hydrogen bond length and angle correlated well with the interaction energies. Meanwhile, the POS-caffeine complex with two higher and almost linear bond angles showed higher binding and interaction energies as compared to the other methylxanthines. Therefore, a donor-acceptor analysis showed that the hydrogen bond strength was proven using the molecular electrostatic potential (MEP), which resulted in parallel outcomes. The research results were believed to be one of the factors that contributed to the rheological behaviour and sensory perception of cocoa products, especially chocolate.

scholarly journals Computational notes on the molecular modeling analyses of flutamide

2020 ◽  
Vol 9 (2) ◽  
pp. 1099-1102
Keyword(s):  
Molecular Modeling ◽  
Active Sites ◽  
Density Functional ◽  
Molecular Electrostatic Potential ◽  
Band Gap Energy ◽  
Total Dipole Moment ◽  
Functional Theory ◽  
Hartree Fock ◽  
Homo Lumo ◽  
Important Drug

Flutamide is one of the recommended and important drug for treating prostate cancer. In spite of this there some scientific reports that recommending against this drug according to some side effects. This is in turn paves the way towards investigating electronic properties of the drug with conventional molecular modeling methods. So that, density functional theory at B3LYP as well as Hartree-Fock HF together with PM3 were utilized to study the drug. Some important parameters are computed in this computational note including total dipole moment, HOMO/LUMO band gap energy and the contour of molecular electrostatic potential in order to map the active sites of the studied drug in terms the charge distributions. Finally, the infrared assignment of the flutamide is introduced based on B3LYP model.

scholarly journals Electronic Properties of Polyvinyl Alcohol/ TiO2/SiO2 Nanocomposites

2020 ◽  
Vol 10 (5) ◽  
pp. 6427-6435
Keyword(s):  
Density Functional ◽  
Band Gap Energy ◽  
Basis Set ◽  
Physical Parameters ◽  
Functional Theory ◽  
Molecular Systems ◽  
Potential Applications ◽  
Sio2 Nanocomposites ◽  
The Given ◽  
Homo Lumo

Molecular modeling shows potential applications for calculating physical as well as chemical parameters of many molecular systems. Physical parameters such as HOMO-LUMO band gap energy (ΔE), total dipole moment (TDM) and the molecular electrostatic potential (MESP) are reflecting the reactivity of the given chemical structure. So, the effect of titanium dioxide (TiO2) and silicon dioxide (SiO2) upon Polyvinyl chloride PVC is studied in terms of physical properties. Such parameters were calculated with density functional theory: B3LYP using LANL2DZ basis set. Model molecules for PVA, TiO2, SiO2, PVA/TiO2, PVA/SiO2 and PVA/TiO2/SiO2 were optimized then ΔE, TDM and MESP were calculated at B3LYP/LANL2DZ. The results indicated that the reactivity of PVA is improved as a result of interaction with TiO2 and SiO2.

Experimental and theoretical approach to novel polyfunctionalized isoxazole

2021 ◽  
Vol 25 ◽  
Author(s):  
Amal Al-Azmi ◽  
Mona A. Shalaby
Keyword(s):  
Density Functional ◽  
Molecular Electrostatic Potential ◽  
Atomic Orbital ◽  
Spectroscopic Studies ◽  
Basis Set ◽  
Reaction Conditions ◽  
Functional Theory ◽  
1H And 13C Nmr ◽  
13C Nuclear Magnetic Resonance ◽  
The Density Functional Theory

: A novel, fast, and straightforward procedure for the synthesis of di- and tri-functionalized isoxazoles starting from 2-ethoxymethylenemalononitrile with different ratios of hydroxylamine in the presence of sodium acetate is described in this paper. The current method’s features include the availability of the starting materials, moderate reaction conditions, and the simplicity of the workup. The structures are characterized using different spectroscopic studies, such as infrared (IR), 1H/13C nuclear magnetic resonance (NMR), and elemental analysis, in addition to X-ray single-crystal determination. The gauge-invariant atomic orbital (GIAO) 1H and 13C NMR chemical shift values of 5-aminoisoxazole-4-carbonitrile and 3,5-diaminoisoxazole-4-carboxamide are calculated in the ground state using the density functional theory (DFT) with the 6- 311+G(d, p) basis set and are compared with the experimental data, in addition to the calculation of the molecular electrostatic potential (MEP) distribution, and the frontier molecular orbitals (FMOs) for the synthesized isoxazoles are illustrated theoretically.

scholarly journals How Accurate Are Static Polarizability Predictions from Density Functional Theory? An Assessment over 132 Species at Equilibrium Geometry

2018 ◽  
Author(s):  
Diptarka Hait ◽  
Martin Head-Gordon
Keyword(s):  
Electric Fields ◽  
Density Functional ◽  
Basis Set ◽  
Equilibrium Geometry ◽  
Density Functionals ◽  
Functional Theory ◽  
First Response ◽  
Complete Basis Set ◽  
Complete Basis Set Limit ◽  
Hybrid Functionals

Static polarizabilities are the first response of the electron density to electric fields, and are therefore important for predicting intermolecular and molecule-field interactions. They also offer a global measure of the accuracy of the treatment of excited states by density functionals in a formally exact manner. We have developed a database of benchmark static polarizabilities for 132 small species at equilibrium geometry, using coupled cluster theory through triple excitations (extrapolated to the complete basis set limit), for the purpose of developing and assessing density functionals. The performance of 60 popular and recent functionals are also assessed, which indicates that double hybrid functionals perform the best, having RMS errors in the range of 2.5-3.8% . Many hybrid functionals also give quite reasonable estimates with 4-5% RMSE. A few meta-GGAs like mBEEF and MVS yield performance comparable to hybrids, indicating potential for improved excited state predictions relative to typical local functionals. Some recent functionals however are found to be prone to catastrophic failure (possibly as a consequence of overparameterization), indicating a need for caution in applying these.

Molecular Structure, Vibrational Spectroscopy and Homo, Lumo Studies of 4-methyl-N-(2-methylphenyl) Benzene Sulfonamide Using DFT Method

2013 ◽  
Vol 665 ◽  
pp. 101-111 ◽  
Author(s):  
K. Sarojini ◽  
H. Krishnan ◽  
Charles C. Kanagam ◽  
S. Muthu
Keyword(s):  
Density Functional ◽  
Molecular Electrostatic Potential ◽  
Structural Parameters ◽  
Dft Method ◽  
Basis Set ◽  
X Ray Diffraction ◽  
Functional Theory ◽  
Homo And Lumo ◽  
Homo Lumo ◽  
Sulfonamide Compound

The sulfonamide compound, 4-methyl-N-(2-methylphenyl) benzene sulfonamide has been synthesized and characterized by FTIR, NMR, UV-Vis, single crystal X-ray diffraction and thermal analysis. Density functional (DFT) calculations have been carried out for the title compound by performing DFT level of theory using B3LYP/6-31G (d,p) basis set. The calculated results show that the predicted geometry can well reproduce the structural parameters. Predicted vibrational frequencies have been assigned and compared with the experimental IR spectra and they support each other. In addition, atomic charges, frontier molecular orbitals and molecular electrostatic potential were carried out by using density functional theory (DFT/B3LYP) 6-31G (d, p) basis set. The calculated Homo and Lumo energies show that charge transfer occur in the molecule.

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