Comparative study of DFT/B3LYP, B3PW91, and HSEH1PBE methods applied to molecular structures and spectroscopic and electronic properties of flufenpyr and amipizone

2015 ◽  
Vol 93 (10) ◽  
pp. 1147-1156 ◽  
Author(s):  
D. Avcı ◽  
S. Bahçeli ◽  
Ö. Tamer ◽  
Y. Atalay
Keyword(s):  
Gas Phase ◽  
Electronic Absorption ◽  
Molecular Electrostatic Potential ◽  
Biological Activities ◽  
Molecular Structures ◽  
Basis Set ◽  
Potential Surfaces ◽  
Ir Frequencies ◽  
Homo Lumo ◽  
C Nmr

The optimized molecular structures, conformational analyses, vibrational (IR) frequencies and their assignments, maximum electronic absorption wavelengths (gas phase and in ethanol solvent), 1H and 13C NMR chemical shift values (gas phase and in CDCl3 solvent), HOMO−LUMO analysis, molecular electrostatic potential surfaces, and nonlinear optical properties of flufenpyr (C14H9ClF4N2O4) and amipizone (C14H16ClN3O) compounds that have many biological activities have been calculated using the DFT/B3LYP, B3PW91, and HSEH1PBE methods with the 6-311G(d,p) basis set in the ground state. A comparison among the results calculated at the mentioned levels indicates that the HSEH1PBE calculations give usually greater values compared with the others in terms of vibrational frequencies, the maximum electronic absorption wavelengths, and HOMO−LUMO energy gaps of the title compounds.

scholarly journals Fukui Function Analysis and Optical, Electronic, and Vibrational Properties of Tetrahydrofuran and Its Derivatives: A Complete Quantum Chemical Study

2015 ◽  
Vol 2015 ◽  
pp. 1-11 ◽  
Author(s):  
Apoorva Dwivedi ◽  
Vikas Baboo ◽  
Abhishek Bajpai
Keyword(s):  
Molecular Electrostatic Potential ◽  
Function Analysis ◽  
Quantum Chemical Study ◽  
Chemical Study ◽  
Basis Set ◽  
Potential Surfaces ◽  
Vibrational Assignments ◽  
Optical And Electronic Properties ◽  
Homo Lumo ◽  
Complete Quantum

The spectroscopic, optical, and electronic properties of tetrahydrofuran and its derivatives were investigated by FTIR techniques. We have done a comparative study of tetrahydrofuran and its derivatives with B3LYP with 6-311 G (d, p) as the basis set. Here we have done a relative study of their structures, vibrational assignments, and thermal, electronic, and optical properties of ttetrahydrofuran and its derivatives. We have plotted frontier orbital HOMO-LUMO surfaces and molecular electrostatic potential surfaces to explain the reactive nature of tetrahydrofuran and its derivatives.

Study on the 4-ethoxy-2-methyl-5-(4-morpholinyl)-3(2H)-pyridazinone using FT-IR, 1H and 13C NMR, UV-vis spectroscopy, and DFT/HSEH1PBE method

2018 ◽  
Vol 96 (9) ◽  
pp. 1042-1052 ◽  
Author(s):  
Bülent Dede ◽  
Davut Avcı ◽  
Semiha Bahçeli
Keyword(s):  
Gas Phase ◽  
Electronic Absorption ◽  
Vibrational Frequencies ◽  
Oscillator Strengths ◽  
Basis Set ◽  
Spectroscopic Techniques ◽  
Vis Spectroscopy ◽  
Td Dft ◽  
Ft Ir ◽  
C Nmr

In this work, the 4-ethoxy-2-methyl-5-(4-morpholinyl)-3(2H)-pyridazinone (or emarfazone, C11H17N3O3) compound, which has many biological functions, has been investigated using FT-IR, 1H and 13C NMR (in CDCl3 solvent), and UV-vis (in ethanol solvent) spectroscopic techniques. Furthermore, the optimized molecular structure, conformational analysis, vibrational frequencies and their assignments, 1H and 13C NMR chemical shift values (in gas phase and CHCl3 solvent), HOMO–LUMO, MEP (molecular electrostatic potential), NBO (natural bond orbital) analyses, and nonlinear optical (NLO) parameters of the title compound in the ground state have been explored by using DFT/HSEH1PBE method with the 6-311++G(d,p) basis set. The electronic absorption maximum wavelengths and oscillator strengths (in gas phase and ethanol solvent) were also obtained at TD-DFT/HSEH1PBE level. A comparison among the experimental and calculated results at the mentioned level indicates that the vibrational frequencies and maximum electronic absorption wavelengths are in good agreement with each other.

SOLVENT EFFECTS ON THE ELECTRONIC STRUCTURE AND NON-LINEAR OPTICAL PROPERTIES OF PYRENE AND SOME OF ITS DERIVATIVES BASED ON DENSITY FUNCTIONAL THEORY

2021 ◽  
Vol 4 (4) ◽  
pp. 236-251
Author(s):  
A. S. Gidado ◽  
L. S. Taura ◽  
A. Musa
Keyword(s):  
Density Functional Theory ◽  
Gas Phase ◽  
Density Functional ◽  
Energy Gap ◽  
Chemical Reactivity ◽  
Basis Set ◽  
Lumo Energy ◽  
Functional Theory ◽  
Organic Optoelectronic ◽  
Homo Lumo

Pyrene (C16H10) is an organic semiconductor which has wide applications in the field of organic electronics suitable for the development of organic light emitting diodes (OLED) and organic photovoltaic cells (OPV). In this work, Density Functional Theory (DFT) using Becke’s three and Lee Yang Parr (B3LYP) functional with basis set 6-311++G(d, p) implemented in Gaussian 03 package was  used to compute total energy, bond parameters, HOMO-LUMO energy gap, electron affinity, ionization potential, chemical reactivity descriptors, dipole moment, isotropic polarizability (α), anisotropy of polarizability ( Δ∝) total first order hyper-polarizability () and second order hyperpolarizability (). The molecules used are pyrene, 1-chloropyrene and 4-chloropyrene  in gas phase and in five different solvents: benzene, chloroform, acetone, DMSO and water. The results obtained show that solvents and chlorination actually influenced the properties of the molecules. The isolated pyrene in acetone has the largest value of HOMO-LUMO energy gap of and is a bit closer to a previously reported experimental value of  and hence is the most stable. Thus, the pyrene molecule has more kinetic stability and can be described as low reactive molecule. The calculated dipole moments are in the order of 4-chloropyrene (1.7645 D) < 1-chloropyrene (1.9663 D) in gas phase. The anisotropy of polarizability ( for pyrene and its derivatives were found to increase with increasing polarity of the solvents.  In a nutshell, the molecules will be promising for organic optoelectronic devices based on their computed properties as reported by this work.

Charge transfer complexes between 2-, 3- and 4-aminopyridines and some π-acceptors in the gas phase and in chloroform: DFT calculations

2016 ◽  
Vol 15 (04) ◽  
pp. 1650029 ◽  
Author(s):  
Nuha Ahmed Wazzan
Keyword(s):  
Charge Transfer ◽  
Dft Calculations ◽  
Gas Phase ◽  
Density Functional ◽  
Molecular Structures ◽  
Basis Set ◽  
Charge Transfer Complexes ◽  
Good Correspondence ◽  
Electronic Distribution ◽  
Picryl Chloride

This work reports density functional theory (DFT) calculations on the molecular structures, electronic distribution, and UV-Vis and IR spectroscopy analysis of charge transfer complexes between aminopyridines (APYs), namely 2-APY, 3-APY and 4-APY, as electron-donors and some [Formula: see text]-electron-acceptors, namely chloranil (CHL), tetracyanoethylene (TCNE) and picryl chloride (PC), formed in the gas phase at the B3LYP/6-31[Formula: see text]G(d,p) method/basis set, and in chloroform at the same method/basis set using PCM as solvation model. Good correspondence was generally obtained between the calculated parameters and the experimental ones.

scholarly journals Study on the chemical potential of apigenin, luteolin, quercetin, and myricetin using the molecular modeling

2021 ◽  
Vol 44 (1) ◽  
pp. 63-66
Author(s):  
Steluta Gosav ◽  
Adriana Hodorogea ◽  
Dan Maftei
Keyword(s):  
Gas Phase ◽  
Chemical Potential ◽  
Chemical Compounds ◽  
Molecular Structures ◽  
Basis Set ◽  
Chemical Hardness ◽  
Equilibrium Geometry ◽  
Hybrid Functional ◽  
Electrophilicity Index ◽  
Quantum Molecular Descriptors

In the present paper, the chemical potential of four flavonoids i.e. apigenin, luteolin, quercetin, and myricetin, of interest in the pharmaceutical industry was investigated using molecular modelling. The equilibrium geometry of molecular structures was calculated in the gas phase and ground state by using B3LYP hybrid functional in conjunction with a 6-311G(d,p) basis set. In order to assess the chemical potential of investigated flavonoids, the main quantum molecular descriptors, such as the dipole moment, the energy of the highest/lowest occupied/unoccupied molecular orbital, the gap energy, the electronegativity, the chemical hardness/softness, and the electrophilicity index have been computed. Also, the influence of the hydroxylation degree of chemical compounds on the chemical potential is discussed.

scholarly journals Crystal structure, DFT and Hirshfeld surface analysis of 2-amino-4-(2-chlorophenyl)-7-hydroxy-4H-benzo[1,2-b]pyran-3-carbonitrile

2019 ◽  
Vol 75 (11) ◽  
pp. 1638-1642
Author(s):  
M. Beemarao ◽  
S. Silambarasan ◽  
A. Jamal Abdul Nasser ◽  
M. Purushothaman ◽  
K. Ravichandran
Keyword(s):  
Surface Analysis ◽  
Molecular Electrostatic Potential ◽  
Energy Levels ◽  
Hirshfeld Surface ◽  
Intramolecular Interactions ◽  
Hirshfeld Surface Analysis ◽  
Maximum Deviation ◽  
Potential Surfaces ◽  
Compound C ◽  
Homo Lumo

The benzopyran ring of the title compound, C16H11ClN2O2, is planar [maximum deviation = 0.079 (2) Å] and is almost perpendicular to the chlorophenyl ring [dihedral angle = 86.85 (6)°]. In the crystal, N—H...O, O—H...N, C—H...O and C—H...Cl hydrogen bonds form inter- and intramolecular interactions. The DFT/B3LYP/6-311G(d,p) method was used to determine the HOMO–LUMO energy levels. The molecular electrostatic potential surfaces were investigated by Hirshfeld surface analysis and two-dimensional fingerprint plots were used to analyse the intermolecular interactions in the molecule.

scholarly journals Synthesis of New Schiff Base of 1,3-Oxazine and 1,3-Thiazine Derivatives Derived from 4-Phenyl Substituted Chalcones and Evaluation of their Antibacterial Activity

2021 ◽  
Vol 33 (3) ◽  
pp. 531-536
Author(s):  
Anupama Sharma ◽  
Sarita Khaturia ◽  
Har Lal Singh
Keyword(s):  
Schiff Base ◽  
Energy Gap ◽  
Biological Activities ◽  
Antibacterial Activities ◽  
Basis Set ◽  
Gram Negative Bacteria ◽  
Important Class ◽  
Lumo Energy ◽  
Homo Lumo

Oxazine and thiazine heterocycles have distinctive interests due to their important class of natural and non-natural products and exhibit high biological activities in the pharmaceutical and biological fields. This work was planned to synthesize Schiff base of 1,3-oxazine and 1,3-thiazine derivative from 4-phenyl substituted chalcones. The structures of the newly synthesized targeted compounds were established from UV, IR, 1H NMR, 13C NMR and DFT calculations. The molecular properties HOMO-LUMO energy, energy gap, softness and harness were calculated using DFT/B3LYP/6-311G (d,p) basis set. in vitro Antibacterial activities of Schiff bases of 1,3-oxazines and 1,3-thiazines derivatives were investigated against Gram-positive (Staphylococcus aureus) and Gram-negative bacteria (Escherichia coli) and compared with each other. It was found that thiazine derivatives showed higher activity.

scholarly journals Synthesis, Spectral and Computational Studies of some 2-(2-(3-Methyl-2,4-Diphenyl-3-Azabicyclo[3.3.1]Nonan-9-Ylidene)Hydrazinyl)Benzo[d]Thiazole Derivatives

2015 ◽  
Vol 61 ◽  
pp. 28-37
Author(s):  
G. Sundararajan ◽  
D. Rajaraman ◽  
S. Bharanidharan ◽  
K. Krishnasamy
Keyword(s):  
Acetic Acid ◽  
Molecular Electrostatic Potential ◽  
Natural Bond Orbital ◽  
Nbo Analysis ◽  
Atomic Charges ◽  
Computational Studies ◽  
Thiazole Derivatives ◽  
Ft Ir ◽  
Homo Lumo ◽  
C Nmr

A series of some 2-(2-(3-methyl-2,4-diphenyl-3-azabicyclo [3.3.1] nonan-9-ylidene) hydrazinyl) benzo [d] thiazole derivatives 11-14 have been synthesized using acetic acid as the catalyst. All the synthesized compounds were characterized by FT-IR, 1H 13C NMR and HSQC spectral analysis. The molecular modelling was carried out for compound 11 by Gaussian 03W package and its HOMO–LUMO, Mulliken atomic charges, Molecular electrostatic potential (MEP), Hyperpolarizability, Thermodynamic propeties and Natural bond orbital (NBO) analysis were discussed

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.

scholarly journals Structural, Spectral, Thermodynamic and HOMO, LUMO Analysis of 2, 6 dithenobenzene-3-enyl 3, 5 dimethyl piperdine-4-one: A quantum chemical analysis

2021 ◽  
Vol 37 (6) ◽  
pp. 1396-1408
Author(s):  
Sangeetha. R.K ◽  
Ayyappan. S S
Keyword(s):  
Density Functional ◽  
Molecular Spectroscopy ◽  
Molecular Geometry ◽  
Basis Set ◽  
Quantum Chemical Analysis ◽  
Potential Surfaces ◽  
Hartree Fock ◽  
Density Mapping ◽  
Nlo Materials ◽  
Homo Lumo

In the current work, the vibrational frequencies, infrared intensities, molecular geometry and Raman scattering were determined and investigated using ab initio Hartree–Fock (HF) and density functional methods with a basis set of 6-311++ G (d, p) of the organic molecule under interpretation. The FT-IR and FT-Raman spectra of titled molecule have been recorded in the region 4000-400 cm-1 and 5000-70 cm-1, respectively. The optimized geometry structures (bond lengths and bond angles) achieved using HF shows the best result with the experimental values of the titled molecule. The frontier molecular orbitals help to distinguish chemical responsiveness and molecular kinetic steadiness, thus HOMO-LUMO analysis can be done using the quantum chemistry to improve thermodynamics. The electron density mapping to electrostatic potential surfaces were involved in finding the reactivity sites of the titled compound. With the help of Gauss view 5.0 and Chemcraft packages, the obtained outputs are analyzed. Hyperpolarizability and non-linear optical effect of isolated molecules of NLO materials are observed to be an extensive tool for molecular spectroscopy research. Therefore, for industrial application, Hyperpolarizability of the molecule is also studied.

Sign in / Sign up

Export Citation Format

Share Document