scholarly journals Theoretically studying the optoelectronic properties of oligomers based on 2.7-divinyl-cabazole

2022 ◽  
Vol 47 (1) ◽  
pp. 40-54
Author(s):  
Mohamed Jabha ◽  
Abdellah El Alaoui ◽  
Abdellah Jarid ◽  
El Houssine Mabrouk
Keyword(s):  
Density Functional ◽  
Energy Surface ◽  
Energy Gap ◽  
Dft Method ◽  
Photovoltaic Cell ◽  
Organic Photovoltaic ◽  
Functional Theory ◽  
Total Potential ◽  
The Density Functional Theory ◽  
Homo Lumo

This work consists of theoretically studying the electronic and optical properties of 9-(4-octyloxyphenyl)-2.7-divinyl-carbazole (PCrV) oligomers. This study has been undertaken using the density functional theory (DFT) method at the B3LYP/6-31G (d,p) level and BP86/6-31G (d,p) level of theory. To evaluate the PCrV-basis systems properties, the structural optimization without geometrical restrictions was performed on the total potential energy surface (TPES). In order to ensure good absorption of radiation, the interest was in increasing the efficiency of the organic photovoltaic cell. For this effect, the (HOMO-LUMO) gap energy of such compounds was reduced in terms of geometric and electronic structure. The BP86 functional gives good results at the energy gap level, while other parameters using the B3LYP functional give the best results.

scholarly journals Chloroquine drug and Graphene complex for treatment of COVID-19

2020 ◽  
Author(s):  
Saeedeh Mohammadi ◽  
Mohammad Esmailpour ◽  
Mina Mohammadi
Keyword(s):  
Density Functional Theory ◽  
Density Functional ◽  
Energy Gap ◽  
Dft Method ◽  
Complex State ◽  
Functional Theory ◽  
The Density Functional Theory ◽  
Structural And Electrical Properties ◽  
Suitable Structure ◽  
Drug Complex

Abstract This paper is a new step in helping the treatment of coronavirus by improving the performance of chloroquine drug. For this purpose, we propose a complex of chloroquine drug with graphene nanoribbon (GNR) scheme. We compute the structural and electrical properties and absorption of chloroquine (C18H26ClN3) and GNR complex using the density functional theory (DFT) method. By creating a drug and GNR complex, the density of states of electrons increases and the energy gap decreases compared to the chloroquine. Also, using absorption calculations and spectrums such as infrared and UV-Vis spectra, we showed that GNR is a suitable structure for creating chloroquine drug complex. Our results show that the dipole moment, global softness and electrophilicity for the drug complex increases compared to the non-complex state. Our calculations can be useful for increasing performance and reducing the side effects of chloroquine, and thus can be effective in treating coronavirus.

scholarly journals Spectroscopic, Electronic and Optical Properties of 4-Nitroimidazole using DFT Calculations

2020 ◽  
Vol 33 (1) ◽  
pp. 83-88
Author(s):  
S. Jeyavijayan ◽  
Palani Murugan
Keyword(s):  
Density Functional ◽  
Energy Gap ◽  
Dft Method ◽  
Nbo Analysis ◽  
Spectroscopic Techniques ◽  
Functional Theory ◽  
Raman Spectroscopic ◽  
Homo Lumo ◽  
Total Energy Distribution ◽  
Ft Raman

Theoretical and experimental vibrational spectra of 4-nitroimidazole were studied by FTIR, FT-Raman spectroscopic techniques and density functional theory (DFT) method. The contributions of the different modes to each wavenumber were confirmed using total energy distribution (TED). The optimized parameters and thermodynamic properties of 4-nitroimidazole have been computed. The charge transfer interactions of the molecule were explained from the small value of HOMO-LUMO energy gap. The NBO analysis, Mulliken’s plot and MEP studies of the molecule have also been reported.

scholarly journals Crystal structure, Hirshfeld surface analysis and DFT studies of (E)-4-methyl-2-{[(4-methylphenyl)imino]methyl}phenol

2020 ◽  
Vol 76 (7) ◽  
pp. 1075-1079
Author(s):  
Nermin Kahveci Yagci ◽  
Md. Serajul Haque Faizi ◽  
Alev Sema Aydin ◽  
Necmi Dege ◽  
Onur Erman Dogan ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Surface Analysis ◽  
Density Functional ◽  
Energy Gap ◽  
Hirshfeld Surface ◽  
Hirshfeld Surface Analysis ◽  
Functional Theory ◽  
Compound C ◽  
The Density Functional Theory ◽  
Homo Lumo

In the title compound, C15H15NO, the configuration of the C=N bond of the Schiff base is E, and an intramolecular O—H...N hydrogen bond is observed, forming an intramolecular S(6) ring motif. The phenol ring is inclined by 45.73 (2)° from the plane of the aniline ring. In the crystal, molecules are linked along the b axis by O—H...N and C—H...O hydrogen bonds, forming polymeric chains. The Hirshfeld surface analysis of the crystal structure indicates that the most important contributions for the packing arrangement are from H...H (56.9%) and H...C/C...H (31.2%) interactions. The density functional theory (DFT) optimized structure at the B3LYP/ 6–311 G(d,p) level is compared with the experimentally determined molecular structure, and the HOMO–LUMO energy gap is provided. The crystal studied was refined as an inversion twin.

Theoretical investigation on vibrational spectroscopic and nonlinear optical activity of 1-(4-chloro phenyl)-3-(4-dimethylamino phenyl) prop-2-en-1-one

2017 ◽  
Vol 95 (4) ◽  
pp. 353-360
Author(s):  
Xiao-Hong Li ◽  
Hong-Ling Cui ◽  
Rui-Zhou Zhang
Keyword(s):  
Density Functional ◽  
Nonlinear Optical ◽  
Energy Gap ◽  
Density Functional Theory Method ◽  
Nbo Analysis ◽  
Frontier Molecular Orbital ◽  
Functional Theory ◽  
The Density Functional Theory ◽  
Electron Donation ◽  
Homo Lumo

The density functional theory method was used to calculate the vibrational spectrum, geometrical structure of 1-(4-chloro phenyl)-3-(4-dimethylamino phenyl) prop-2-en-1-one in the ground state. The analysis of natural bond orbital (NBO) was also performed. The infrared spectrum was obtained and interpreted by means of potential energies distributions. NBO analysis shows that electron donation from LP(1)N atom to the anti-bonding acceptor σ*(C6–C12) of the phenyl ring results in the stabilization of 43.9 kJ/mol. The predicted NLO properties show that the βtot of the title compound is larger than that of urea and is a good candidate as a nonlinear optical material. In addition, the frontier molecular orbital is also investigated. The high βtot value and the low HOMO–LUMO energy gap assert the suitability of the grown crystal for NLO applications.

scholarly journals Adsorption Properties of O2onCr5Nanostructures: A DFT Study

2011 ◽  
Vol 8 (3) ◽  
pp. 982-991
Author(s):  
Mohammad T. Baei ◽  
Ali Kazemi Babaheydari ◽  
Parviz Torabi
Keyword(s):  
Density Functional ◽  
Energy Gap ◽  
Stable State ◽  
Oxygen Molecule ◽  
Adsorption Properties ◽  
Basis Sets ◽  
Bridge Site ◽  
Functional Theory ◽  
The Density Functional Theory ◽  
Homo Lumo

Based on the density functional theory (DFT) adsorption properties of oxygen molecule on Cr5nanostructures at various positions (top, bridge and central sites) were investigated. Geometry optimizations and vibrational frequencies of them were carried out at B3LYP level of theory with LANL2DZ and 6-31G*basis sets using Gaussian 98 suites of program. Their thermodynamic properties were estimated. We have also investigated the total electronic properties, HOMO, LUMO and energy gap for Cr5nanostructures with O2. The result showed that the adsorption of O2on Cr5nanocluster in horizontal bridge site is the most stable state of adsorption and its binding energy is strong, -145.88 kcal/mol.

scholarly journals Crystal structure, Hirshfeld surface analysis and DFT studies of 4-methyl-2-({[4-(trifluoromethyl)phenyl]imino}methyl)phenol

2020 ◽  
Vol 76 (8) ◽  
pp. 1325-1330
Author(s):  
Md. Serajul Haque Faizi ◽  
Emine Berrin Cinar ◽  
Onur Erman Dogan ◽  
Alev Sema Aydin ◽  
Erbil Agar ◽  
...  
Keyword(s):  
Surface Analysis ◽  
Density Functional ◽  
Energy Gap ◽  
Crystal Packing ◽  
Hirshfeld Surface ◽  
Hirshfeld Surface Analysis ◽  
Functional Theory ◽  
Compound C ◽  
The Density Functional Theory ◽  
Homo Lumo

The title compound, C15H12F3NO, crystallizes with one molecule in the asymmetric unit. The configuration of the C=N bond is E and there is an intramolecular O—H...N hydrogen bond present, forming an S(6) ring motif. The dihedral angle between the mean planes of the phenol and the 4-trifluoromethylphenyl rings is 44.77 (3)°. In the crystal, molecules are linked by C—H...O interactions, forming polymeric chains extending along the a-axis direction. The Hirshfeld surface analysis indicates that the most important contributions to the crystal packing are from C...H/H...C (29.2%), H...H (28.6%), F...H/H...F (25.6%), O...H/H...O (5.7%) and F...F (4.6%) interactions. The density functional theory (DFT) optimized structure at the B3LYP/6-311 G(d,p) level is compared with the experimentally determined molecular structure in the solid state. The HOMO–LUMO behaviour was elucidated to determine the energy gap. The crystal studied was refined as an inversion twin.

STRUCTURES, ABSORPTION SPECTRA, AND ELECTRONIC PROPERTIES OF POLYFLUORENE AND ITS DERIVATIVES: A THEORETICAL STUDY

2006 ◽  
Vol 05 (03) ◽  
pp. 595-608 ◽  
Author(s):  
KRIENGSAK SRIWICHITKAMOL ◽  
SONGWUT SURAMITR ◽  
POTJAMAN POOLMEE ◽  
SUPA HANNONGBUA
Keyword(s):  
Density Functional Theory ◽  
Density Functional ◽  
Energy Gap ◽  
Level Energy ◽  
Excitation Energies ◽  
Lumo Energy ◽  
Functional Theory ◽  
Local Energy Minimum ◽  
Pi Systems ◽  
Homo Lumo

The structural and energetic properties of polyfluorene and its derivatives were investigated, using quantum chemical calculations. Conformational analysis of bifluorene was performed by using ab initio (HF/6-31G* and MP2/6-31G*) and density functional theory (B3LYP/6-31G*) calculations. The results showed that the local energy minimum of bifluorene lies between the coplanar and perpendicular conformation, and the B3LYP/6-31G* calculations led to the overestimation of the stability of the planar pi systems. The HOMO-LUMO energy differences of fluorene oligomers and its derivatives — 9,9-dihexylfluorene (DHPF), 9,9-dioctylfluorene (PFO), and bis(2-ethylhexyl)fluorene (BEHPF) — were calculated at the B3LYP/6-31G* level. Energy gaps and effective conjugation lengths of the corresponding polymers were obtained by extrapolating HOMO-LUMO energy differences and the lowest excitation energies to infinite chain length. The lowest excitation energies and the maximum absorption wavelength of polyfluorene were also performed, employing the time-dependent density functional theory (TDDFT) and ZINDO methods. The extrapolations, based on TDDFT and ZINDO calculations, agree well with experimental results. These theoretical methods can be useful for the design of new polymeric structures with a reducing energy gap.

First principles analysis of oxygen vacancy formation and migration in Sr2BMoO6 (B = Mg, Co, Ni)

RSC Advances ◽  
2016 ◽  
Vol 6 (38) ◽  
pp. 31968-31975 ◽  
Author(s):  
Shuai Zhao ◽  
Liguo Gao ◽  
Chunfeng Lan ◽  
Shyam S. Pandey ◽  
Shuzi Hayase ◽  
...  
Keyword(s):  
Density Functional Theory ◽  
Oxygen Vacancy ◽  
First Principles ◽  
Density Functional ◽  
Dft Method ◽  
Double Perovskites ◽  
Functional Theory ◽  
Oxygen Vacancy Formation ◽  
The Density Functional Theory ◽  
And Migration

In this work, we present a detailed first-principles investigation on the stoichiometric and oxygen-deficient structures of double perovskites, Sr2BMoO6 (B = Mg, Co and Ni), using the density functional theory (DFT) method.

scholarly journals Vibrational Study and Force Field of the Citric Acid Dimer Based on the SQM Methodology

2011 ◽  
Vol 2011 ◽  
pp. 1-10 ◽  
Author(s):  
Laura Cecilia Bichara ◽  
Hernán Enrique Lanús ◽  
Evelina Gloria Ferrer ◽  
Mónica Beatriz Gramajo ◽  
Silvia Antonia Brandán
Keyword(s):  
Citric Acid ◽  
Force Field ◽  
Density Functional ◽  
Solid Phase ◽  
Dft Method ◽  
Electronic Charge ◽  
Functional Theory ◽  
The Density Functional Theory ◽  
Atoms In Molecules Theory ◽  
Best Fit

We have carried out a structural and vibrational theoretical study for the citric acid dimer. The Density Functional Theory (DFT) method with the B3LYP/6-31G∗ and B3LYP/6-311++ methods have been used to study its structure and vibrational properties. Then, in order to get a good assignment of the IR and Raman spectra in solid phase of dimer, the best fit possible between the calculated and recorded frequencies was carry out and the force fields were scaled using the Scaled Quantum Mechanic Force Field (SQMFF) methodology. An assignment of the observed spectral features is proposed. A band of medium intensity at 1242  together with a group of weak bands, previously not assigned to the monomer, was in this case assigned to the dimer. Furthermore, the analysis of the Natural Bond Orbitals (NBOs) and the topological properties of electronic charge density by employing Bader's Atoms in Molecules theory (AIM) for the dimer were carried out to study the charge transference interactions of the compound.

CH2O Adsorption on M (M = Li, Mg and Al) Atom Deposited ZnO Nano-Cage: DFT Study

2018 ◽  
Vol 786 ◽  
pp. 384-392 ◽  
Author(s):  
Hussein Y. Ammar
Keyword(s):  
Density Functional Theory ◽  
Bond Length ◽  
Density Functional ◽  
Functional Theory ◽  
The Density Functional Theory ◽  
Structural And Electronic Properties ◽  
Formaldehyde Molecule ◽  
Electronic Configurations ◽  
Adsorption Energies ◽  
Homo Lumo

The structural and electronic properties of Li, Mg and Al deposited ZnO nanocages and their effects on the adsorption of formaldehyde molecule have been investigated using the density functional theory (DFT) computations. To understand the behavior of the adsorbed CH2O molecule on the ZnO nanocage, results of DFT calculations of the M-deposited nanocages (M=Li, Mg and Al), as well as complex systems consisting of the adsorbed CH2O molecule on M-deposited ZnO nanocage were reported. The results presented include adsorption energies, bond lengths, electronic configurations, density of states and molecular orbitals. It was found that, the most energetically stable adsorption configurations of CH2O molecule on the bare ZnO leads to 12% dilation in C=O bond length of CH2O and 14% decrease in HOMO-LUMO gap of ZnO cluster. The most energetically stable adsorption configurations of CH2O molecule on Li, Mg and Al-deposited ZnO lead to 4%, 4% and 11% dilation in C=O bond length of CH2O and-0.66, -45 and , +66% change in HOMO-LUMO gap of ZnO nanocages, respectively. The interaction between CH2O with bare ZnO and M-deposited ZnO nanocages is attributed to charge transfer mechanism. These results may be meaningful for CH2O degradation and detection.

Sign in / Sign up

Export Citation Format

Share Document