scholarly journals Molecular Geometry, NLO, MEP, HOMO-LUMO and Mulliken Charges of Substituted Piperidine Phenyl Hydrazines by Using Density Functional Theory

2019 ◽  
Vol 32 (2) ◽  
pp. 401-407
Author(s):  
M. Dinesh Kumar ◽  
P. Rajesh ◽  
R. Priya Dharsini ◽  
M. Ezhil Inban
Keyword(s):  
Density Functional Theory ◽  
Density Functional ◽  
Chemical Reactivity ◽  
Molecular Geometry ◽  
Basis Set ◽  
Functional Theory ◽  
B3lyp Method ◽  
Reactivity Descriptor ◽  
Homo Lumo ◽  
Optimized Geometries

The quantum chemical calculations of organic compounds viz. (E)-1-(2,6-bis(4-chlorophenyl)-3-ethylpiperidine-4-ylidene)-2-phenyl-hydrazine (3ECl), (E)-1-(2,6-bis(4-chlorophenyl)-3-methylpiperidine-4-ylidene)-2-phenylhydrazine (3MCl) and (E)-1-(2,6-bis(4-chloro-phenyl)-3,5-dimethylpiperidine-4-ylidene)-2-phenylhydrazine (3,5-DMCl) have been performed by density functional theory (DFT) using B3LYP method with 6-311G (d,p) basis set. The electronic properties such as Frontier orbital and band gap energies have been calculated using DFT. Global reactivity descriptor has been computed to predict chemical stability and reactivity of the molecule. The chemical reactivity sites of compounds were predicted by mapping molecular electrostatic potential (MEP) surface over optimized geometries and comparing these with MEP map generated over crystal structures. The charge distribution of molecules predict by using Mulliken atomic charges. The non-linear optical property was predicted and interpreted the dipole moment (μ), polarizability (α) and hyperpolarizability (β) by using density functional theory.

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.

scholarly journals Density Functional Theory and Molecular Docking Investigations of the Chemical and Antibacterial Activities for 1-(4-Hydroxyphenyl)-3-phenylprop-2-en-1-one

Molecules ◽  
2021 ◽  
Vol 26 (12) ◽  
pp. 3631
Author(s):  
Ahmed M. Deghady ◽  
Rageh K. Hussein ◽  
Abdulrahman G. Alhamzani ◽  
Abeer Mera
Keyword(s):  
Density Functional Theory ◽  
Antibacterial Activity ◽  
Molecular Docking ◽  
Carbonyl Group ◽  
Active Sites ◽  
Density Functional ◽  
Chemical Reactivity ◽  
Basis Set ◽  
Molecular Docking Study ◽  
Functional Theory

The present investigation informs a descriptive study of 1-(4-Hydroxyphenyl) -3-phenylprop-2-en-1-one compound, by using density functional theory at B3LYP method with 6-311G** basis set. The oxygen atoms and π-system revealed a high chemical reactivity for the title compound as electron donor spots and active sites for an electrophilic attack. Quantum chemical parameters such as hardness (η), softness (S), electronegativity (χ), and electrophilicity (ω) were yielded as descriptors for the molecule’s chemical behavior. The optimized molecular structure was obtained, and the experimental data were matched with geometrical analysis values describing the molecule’s stable structure. The computed FT-IR and Raman vibrational frequencies were in good agreement with those observed experimentally. In a molecular docking study, the inhibitory potential of the studied molecule was evaluated against the penicillin-binding proteins of Staphylococcus aureus bacteria. The carbonyl group in the molecule was shown to play a significant role in antibacterial activity, four bonds were formed by the carbonyl group with the key protein of the bacteria (three favorable hydrogen bonds plus one van der Waals bond) out of six interactions. The strong antibacterial activity was also indicated by the calculated high binding energy (−7.40 kcal/mol).

scholarly journals Stability and magnetic properties of isomorphous substituted Si7-xMnx+

2018 ◽  
Vol 56 (1) ◽  
pp. 64
Author(s):  
Nguyen Thanh Tung ◽  
Nguyen Thi Mai ◽  
Ngo Tuan Cuong
Keyword(s):  
Density Functional Theory ◽  
Magnetic Properties ◽  
Magnetic Moment ◽  
Density Functional ◽  
Basis Set ◽  
Pentagonal Bipyramid ◽  
Functional Theory ◽  
Electronic Configurations ◽  
Method Of Density Functional ◽  
Optimized Geometries

The optimized geometries, stability, and magnetic properties of cationic clusters Si7+, Si6Mn+, and Si5Mn2+ have been determined by the method of density functional theory using the B3P86/6-311+G(d) functional/basis set. Their electronic configurations have been analyzed to understand the influence of substituting Si atoms by Mn atoms on the structural and magnetic aspects of Si7+. It is shown that the manganese dopant does not alter the structure of the silicon host but significantly changes its stability and magnetism. In particular, while the magnetic moment of Si7+ is 1 mB, Si5Mn2+ exhibits a strong magnetic moment of 9 mB and that of Si6Mn+ takes a relatively high value of 4 mB. Among studied clusters, the pentagonal bipyramid Si5Mn2+ is assigned as the most stable one.

scholarly journals Molecular Structure and Vibrational Spectra of 2-Ethylhexyl Acrylate by Density Functional Theory Calculations

2013 ◽  
Vol 2013 ◽  
pp. 1-14 ◽  
Author(s):  
Ottman Belaidi ◽  
Tewfik Bouchaour ◽  
Ulrich Maschke
Keyword(s):  
Density Functional Theory ◽  
Infrared Spectrum ◽  
Density Functional ◽  
Density Functional Theory Calculations ◽  
Molecular Geometry ◽  
Electron Diffraction Data ◽  
Functional Theory ◽  
Infrared Intensities ◽  
The Fourier Transform ◽  
Optimized Geometries

The Fourier transform infrared spectra (FTIR) of 2-ethylhexyl acrylate have been measured in liquid phase. The molecular geometry, vibrational frequencies, and infrared intensities have been calculated by using density functional theory. We found two local minima representing s-cis and s-trans conformations for 2-ethylhexyl acrylate molecule. The optimized geometries at DFT//B3LYP/6-311+ are in good agreement with electron diffraction data of methyl acrylate for the acrylic group. The two conformers were used for the interpretation of the experimental infrared spectrum of title compound. PED calculations are represented for a more complete and concise assignment. There is one band in the infrared spectrum at 1646 cm−1 that definitely indicates the conformer with s-trans arrangement of acrylic moiety to be present or not in the liquid 2-ethylhexyl acrylate.

scholarly journals Quantum chemical studies on the molecular structure, spectroscopic and electronic properties of (6-Methoxy-2-oxo-2H-chromen-4-yl)-methyl pyrrolidine-1-carbodithioate

2016 ◽  
Vol 34 (4) ◽  
pp. 886-904 ◽  
Author(s):  
Meryem Evecen ◽  
Hasan Tanak
Keyword(s):  
Density Functional Theory ◽  
Density Functional ◽  
Electronic Absorption Spectra ◽  
Chemical Shifts ◽  
Density Functional Theory Calculations ◽  
Molecular Geometry ◽  
Basis Set ◽  
Functional Theory ◽  
Hartree Fock ◽  
Chemical Studies

AbstractIn this paper, the molecular geometry, vibrational frequencies and chemical shifts of (6-Methoxy-2-oxo-2H-chromen-4-yl)methyl pyrrolidine-1-carbodithioate in the ground state have been calculated using the Hartree-Fock and density functional methods with the 6-311++G(d,p) basis set. To investigate the nonlinear optical properties of the title compound, the polarizability and the first hyperpolarizability were calculated. The conformational properties of the molecule have been determined by analyzing molecular energy properties. Using the time dependent density functional theory, electronic absorption spectra have been calculated. Frontier molecular orbitals, natural bond orbitals, natural atomic charges and thermodynamical parameters were also investigated by using the density functional theory calculations.

scholarly journals Density Functional Theory Study on Conformers of Benzoylcholine Chloride

2013 ◽  
Vol 2013 ◽  
pp. 1-10 ◽  
Author(s):  
Mustafa Karakaya ◽  
Fatih Ucun ◽  
Ahmet Tokatlı
Keyword(s):  
Density Functional Theory ◽  
Ground State ◽  
Density Functional ◽  
Atomic Orbital ◽  
Nbo Analysis ◽  
Vibrational Frequencies ◽  
Molecular Structures ◽  
Basis Set ◽  
Functional Theory ◽  
B3lyp Method

The optimized molecular structures and vibrational frequencies and also gauge including atomic orbital (GIAO)1H and13C NMR shift values of benzoylcholine chloride [(2-benzoyloxyethyl) trimethyl ammonium chloride] have been calculated using density functional theory (B3LYP) method with 6-31++G(d) basis set. The comparison of the experimental and calculated infrared (IR), Raman, and nuclear magnetic resonance (NMR) spectra has indicated that the experimental spectra are formed from the superposition of the spectra of two lowest energy conformers of the compound. So, it was concluded that the compound simultaneously exists in two optimized conformers in the ground state. Also the natural bond orbital (NBO) analysis has supported the simultaneous exiting of two conformers in the ground state. The calculated optimized geometric parameters (bond lengths and bond angles) and vibrational frequencies for both the lowest energy conformers were seen to be in a well agreement with the corresponding experimental data.

scholarly journals Synthesis and Density Functional Theory Studies of Novel Heterocycle Tethered with Pyrazole and Benzimidazole Structural Motifs

2019 ◽  
Vol 9 (1S3) ◽  
pp. 272-277
Keyword(s):  
Density Functional Theory ◽  
Electron Transfer ◽  
Density Functional ◽  
Basis Set ◽  
Computational Studies ◽  
Functional Theory ◽  
Nlo Materials ◽  
Future Utility ◽  
Homo Lumo ◽  
Better Than

A novel heterocyclic chemical entity, 2-(1H-benzo[d]imidazol-2-yl)-3-(3-(4-nitrophenyl)-1-phenyl-1Hpyrazol-4-yl)acrylonitrile) (1f) has been synthesized and characterized. Computational studies were carried out using Gaussian 9 program with DFT/B3LYP/6311(++G) basis set. The structural optimization was computed successfully. Further, HOMO–LUMO analysis promises the incidence of inter electron transfer within the molecule. The theoretically determined hyperpolarizability value is nearly 9.5 times better than standard urea, suggesting its future utility as an efficient NLO optic material or its utility as an effective intermediate to construct better NLO materials

scholarly journals Synthesis and Structure Characterization of 1-(4-Bromophenyl)-3-(2-Chloro-6-Fluorophenyl) Prop-2-En-1-One Using Spectroscopic Techniques and Density Functional Theory

2021 ◽  
Vol 9 (11) ◽  
pp. 1745-1752
Author(s):  
Virupakshi M. Bhumannavar
Keyword(s):  
Density Functional Theory ◽  
Density Functional ◽  
Structure Characterization ◽  
Basis Set ◽  
Experimental Techniques ◽  
Spectroscopic Techniques ◽  
Functional Theory ◽  
Hartree Fock ◽  
Homo Lumo

Abstract: The structural confirmation of the 1-(4-Bromophenyl)-3-(2-chloro-6-fluorophenyl) prop-2-en-1-one compound is done by experimental techniques. Experimental techniques FTIR, proton NMR, UV-Visible, performed for the compound. The experimentally obtained results are compared with density functional theory obtained results. The decomposition and melting point of the compound is obtained by TGA & DTA. Density functional theory is performed for the 1-(4-Bromophenyl)-3-(2- chloro-6-fluorophenyl) prop-2-en-1-one compound B3LYP/6-311G++(d,p) basis set. Time dependent density functional theory calculated for three different methods B3LYP, Hartree-Fock and CAMB3LYP also employed for the 2C6FBC at 6-311G++(d,p) basis set. Keywords: DFT Study, HOMO-LUMO, FTIR, 1H NMR, TGA/DTA, chalcone

Spectroscopic investigation, HOMO–LUMO energies, natural bond orbital (NBO) analysis and thermodynamic properties of two-armed macroinitiator containing coumarin with DFT quantum chemical calculations

2016 ◽  
Vol 94 (6) ◽  
pp. 583-593 ◽  
Author(s):  
Feride Akman
Keyword(s):  
Density Functional Theory ◽  
Molecular Orbital ◽  
Electrostatic Potential ◽  
Density Functional ◽  
Natural Bond Orbital ◽  
Dft Method ◽  
Basis Set ◽  
Orbital Method ◽  
Functional Theory ◽  
Homo Lumo

In the present work, two-armed macroinitiator containing coumarin were synthesized, characterized by Fourier transform infrared spectroscopy and 1H nuclear magnetic resonance techniques and investigated theoretically using density functional theory (DFT) calculations. The molecular geometry, fundamental vibrational frequencies, atomic charges obtained from atomic polar tensors and Mulliken were analyzed by means of structure optimizations based on the DFT method with 6-31G+(d, p) as a basis set. The 1H chemical shifts were calculated by the gauge-including atomic orbital method and compared with available experimental data. The electronic properties, such as highest occupied molecular orbital – lowest unoccupied molecular orbital (HOMO–LUMO) energies, electron affinity, electronegativity, ionization energy, hardness, chemical potential, global softness, and global electrophilicity were calculated by using the DFT method. The electrostatic potential and molecular electrostatic potential surfaces were performed to predict the reactive sites of the two-armed macroinitiator. The energy difference between acceptor and donor and stabilization energy were determined using natural bond orbital analysis. The results show that the occurrence of intramolecular charge transfers within the polymer. Time-dependent density functional theory calculations of visible spectra were analyzed at different solvents. Finally, thermodynamic functions, such as enthalpy, heat capacity, and entropy, of the two-armed macroinitiator at different temperatures were calculated and the relationship with temperature was investigated.

DENSITY FUNCTIONAL STUDY OF THE EFFECTS OF THE SUBSTITUENTS ON THE CHEMICAL REACTIVITY OF THE INDIGO MOLECULE

2013 ◽  
Vol 12 (03) ◽  
pp. 1350013 ◽  
Author(s):  
FRANCISCO CERVANTES-NAVARRO ◽  
DANIEL GLOSSMAN-MITNIK
Keyword(s):  
Density Functional Theory ◽  
Ground State ◽  
Density Functional ◽  
Chemical Reactivity ◽  
Theoretical Work ◽  
Basis Set ◽  
Functional Study ◽  
Functional Theory ◽  
Density Functional Study ◽  
Local Reactivity

This theoretical work applied density functional theory (DFT) to study the ground state of the indigo molecule and the effects of substituents. B3LYP was employed with the 6-31G[d,p] basis set. The obtained energies were used to describe the local reactivity [Δf(r)]. The effects of the substituents on the local reactivity were dependent on the molecular positions of the substituents.

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