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

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 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.

ELECTRON TRANSFER MAKES D3h (78:5) CAGE EASY TO FORM M2@C78(M = La, Ce): A RELATIVISTIC DENSITY-FUNCTIONAL THEORY STUDY

2012 ◽  
Vol 11 (01) ◽  
pp. 197-207 ◽  
Author(s):  
CE HAO ◽  
HONGJIANG LI ◽  
GUORONG JIA ◽  
SHENMIN LI ◽  
JIESHAN QIU
Keyword(s):  
Density Functional Theory ◽  
Electron Transfer ◽  
Density Functional ◽  
Functional Theory ◽  
Endohedral Metallofullerenes ◽  
Metal Atoms ◽  
The Stability ◽  
Homo Lumo ◽  
Good Agreement ◽  
C Nmr

Applying relativistic density functional theory to isomers of C 78 and M 2@ C 78( M = La , Ce ), we calculate and analyze the relative energies and HOMO–LUMO gaps of neutral and hexaanion ( -6 charged) C 78 isomers. Our results indicate that the [Formula: see text] (5) isomer is the most stable, and it illustrate that electron transfer plays an important role in controlling the stability of endohedral metallofullerenes. We also calculate the electronic structures of there neutral isomers, and based on their LUMO + 2 and LUMO + 3 gaps, we explain why it is easier to encage two metal atoms in D3h′ (78:5). To further elucidate this issue, we theoretically characterize M 2@ C 78( M = La , Ce ) and compare the relative energies and the HOMO–LUMO gap of the two isomers M 2@ C 78 (4) and the M 2@ C 78 (5) ( M = La , Ce ). The results indicate that M 2@ C 78 (5) is more stable than M 2@ C 78 (4). Furthermore, the good agreement between the experimental and computed 13C NMR chemical shift of the isomer M 2@ C 78 (5) provided strong evidence that M 2@ C 78 forms a D3h′ (78:5) cage.

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.

scholarly journals Electronic Structure, Nonlinear Optical Properties, and Vibrational Analysis of Gemifloxacin by Density Functional Theory

2012 ◽  
Vol 27 ◽  
pp. 185-206 ◽  
Author(s):  
Shamoon Ahmad Siddiqui ◽  
Tabish Rasheed ◽  
Mohd Faisal ◽  
Anoop Kumar Pandey ◽  
Sher Bahadar Khan
Keyword(s):  
Density Functional Theory ◽  
Optical Properties ◽  
Density Functional ◽  
Normal Modes ◽  
Vibrational Analysis ◽  
Basis Set ◽  
Functional Theory ◽  
Linear Optical Properties ◽  
Equilibrium Geometries ◽  
Homo Lumo

The non-linear optical properties of gemifloxacin (C18H20FN5O4) have been examined using density functional theory (DFT). The molecular HOMO, LUMO composition, their respective energy gaps, MESP contours/surfaces have also been drawn to explain the activity of gemifloxacin. The equilibrium geometries and harmonic frequencies of title molecule was determined and analyzed at DFT/B3LYP level employing the 6-31G(d,p) basis set. The skeleton of both the optimized molecules is non-planar. In general, a good agreement between experimental and calculated normal modes of vibrations has been observed.

scholarly journals Novel Benzimidazole Bejeweled Pyrazole: Synthesis, Characterization and Density Functional Theory Analysis

2019 ◽  
Vol 9 (1S3) ◽  
pp. 260-265
Keyword(s):  
Density Functional Theory ◽  
Good Yield ◽  
Density Functional ◽  
Knoevenagel Condensation ◽  
Basis Set ◽  
Spectroscopic Methods ◽  
Theory Analysis ◽  
Functional Theory ◽  
B3lyp Calculation ◽  
Homo Lumo

A novel benzimidazole festooned pyrazolyl acrylonitrile 6 has been synthesized with a good yield via Knoevenagel condensation method and the structure has been elucidated based on analytical and spectroscopic methods. DFT-B3LYP calculation with 6-311 G(d,p) basis set has been performed for optimization of the structure and to determine their structural - energy parameters. The HOMO –LUMO analysis and polarizability cum hyper polarizability values ensure compound 6 is likely to be NLO material that could also find use in solar cells. Besides, the electronic properties and the structural cores imply that the molecule could also serve as bioagent.

scholarly journals Synthesis, characterization and computational studies of 2-cyano-6-methoxybenzothiazole as a firefly-luciferin precursor

2018 ◽  
Vol 24 (5) ◽  
pp. 255-258
Author(s):  
Ghasem Shahmoradi ◽  
Saeid Amani
Keyword(s):  
Density Functional Theory ◽  
Density Functional ◽  
Basis Set ◽  
Computational Studies ◽  
Stable Conformation ◽  
Functional Theory ◽  
Novel Approach ◽  
B3lyp Method ◽  
The Density Functional Theory ◽  
Firefly Luciferin

Abstract A novel approach to the synthesis of 2-cyano-6-methoxybenzothiazole via the Cu-catalyzed cyanation of 2-iodo-6-methoxybenzothiazole was developed. K4[Fe(CN)6] was used as a source of cyanide, and a Cu/N,N,N′,N′-tetramethylethylenediamine (TMEDA) system was utilized as a catalyst. This approach is scalable and can be practiced with operational benign. The most stable conformation of 2-cyano-6-methoxybenzothiazole was delineated using the density functional theory (DFT)/B3LYP method with 6-311++G(d, p) basis set.

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