scholarly journals Molecular modelling, spectroscopic characterization and nonlinear optical analysis on N-Acetyl-DL-methionine

2020 ◽  
Vol 66 (6 Nov-Dec) ◽  
pp. 749
Author(s):  
N. Günay ◽  
Ö. Tamer ◽  
D. Avcı ◽  
E. Tarcan ◽  
Y. Atalay
Keyword(s):  
Electronic Properties ◽  
Title Compound ◽  
Density Functional ◽  
Nonlinear Optical ◽  
Energy Gap ◽  
Spectroscopic Characterization ◽  
Oscillator Strengths ◽  
Basis Set ◽  
Molecular Electrostatic Potential Surface ◽  
Experimental Values

In this present methodical study, on the basis of the density functional theory (DFT), the first-principles calculations have been employed successfully to study the structural and electronic properties of N-acetyl-DL-methionine (C7H13NO3S) which is a derivative of DL-methionine which is also known DL-2-amino-4-methyl-thiobutanoic acid. Optimized molecular structure, vibrational frequencies and also 13C and 1H NMR chemical shift values of the title compound are provided in a detailed manner by using B3LYP and HSEH1PBE functionals by applying 6-311++G(d,p) basis set for calculations using Gaussian 09W program. The comparison of the calculated values with the experimental values provides important information about the title compound. In addition, the electronic properties (UV-Vis calculations) of the title compound, such as HOMO-LUMO energy values and energy gap, absorption wavelengths, oscillator strengths were performed basing on the optimized structure in gas phase. Moreover, the molecular electrostatic potential surface, dipole moment, nonlinear optical properties, linear polarizabilities and first hyperpolarizabilities and chemical parameters have also been studied.

scholarly journals Predictive calculation of structural, nonlinear optical, electronic and thermodynamic properties of andirobin molecule from ab initio and DFT methods

2021 ◽  
Vol 3 (9) ◽  
Author(s):  
M. T. Ottou Abe ◽  
C. L. Nzia ◽  
L. Sidjui Sidjui ◽  
R. A. Yossa Kamsi ◽  
C. D. D. Mveme ◽  
...  
Keyword(s):  
Thermodynamic Properties ◽  
Density Functional ◽  
Nonlinear Optical ◽  
Energy Gap ◽  
Basis Set ◽  
Dft Methods ◽  
Functional Theory ◽  
Hartree Fock ◽  
H Nmr ◽  
Experimental Values

AbstractThe structural, nonlinear optical, electronic and thermodynamic properties of andirobin molecule were carried out by density functional theory at the B3LYP, WB97XD level and at the Restricted Hartree–Fock level by employing 6–311G(d,p) basis set. The obtained values of bond lengths, bond angles, 1H NMR and 13C NMR are in good agreement with experimental values. The dipole moment and first static hyperpolarizability show that andirobin can be applied in nonlinear optical devices. HOMO–LUMO energy gap values were found to be greater than 4 eV and lead us to the conclusion that this molecule can be used as insulator in many electronic devices. The thermal energy (E), molar heat capacity at constant volume $$(C_{v}$$ ( C v ) and entropy (S) were also calculated.

STRUCTURAL AND ELECTRONIC PROPERTIES OF FINITE-LENGTH SINGLE-WALLED CARBON AND SILICON CARBIDE NANOTUBES: DFT STUDY

2013 ◽  
Vol 27 (29) ◽  
pp. 1350210 ◽  
Author(s):  
IGOR K. PETRUSHENKO ◽  
NIKOLAY A. IVANOV
Keyword(s):  
Silicon Carbide ◽  
Electronic Properties ◽  
Density Functional ◽  
Energy Gap ◽  
Basis Set ◽  
Functional Theory ◽  
Single Walled Carbon ◽  
Silicon Carbide Nanotubes ◽  
Structural And Electronic Properties ◽  
Walled Carbon Nanotubes

This paper presents a systematical analysis of the structure and electronic properties of armchair single-walled carbon nanotubes (SWCNTs) as well as single-walled silicon carbide nanotubes ( SiCNTs ) by using density functional theory. The geometries of all species were optimized at the B3LYP level of theory using the SVP basis set. The different behavior of C – C bonds "parallel" and "perpendicular" to the nanotube axis has been found. The HOMO–LUMO energy gap, ionization potential, electron affinity, electronegativity and hardness of studied tubes were compared. The influence of both SWCNTs and SiCNTs lengths on their electronic properties has been analyzed.

FIRST-PRINCIPLES STUDY OF THE ELECTRONIC, LINEAR, AND NONLINEAR OPTICAL PROPERTIES OF Li(Nb, Ta)O3

2010 ◽  
Vol 24 (32) ◽  
pp. 6277-6290 ◽  
Author(s):  
SULEYMAN CABUK
Keyword(s):  
First Principles ◽  
Density Functional ◽  
Nonlinear Optical ◽  
Energy Gap ◽  
Local Density ◽  
Theoretical Calculations ◽  
Total Density ◽  
Functional Theory ◽  
Experimental Values ◽  
Electron Energy Loss

We investigate the energy band structure, total density of states, the linear, nonlinear optical (NLO) response, and the electron energy-loss spectrum for Li(Nb, Ta)O 3 using first principles calculations based on density functional theory in its local density approximation. Our calculation shows that these compounds have similar structures. The indirect band gaps of 3.39 eV (LiNbO3) and 3.84 eV (LiTaO3) at the Γ–Z direction in the Brillouin zone are found. A simple scissor approximation is applied to adjust the band energy gap from the calculations to match the experimental values. The optical spectra are analyzed and the origins of some of the peaks in the spectra are discussed in terms of calculated electronic structure. Calculations are reported for the frequency-dependent complex second-order NLO susceptibilities [Formula: see text] up to 10 eV and for zero-frequency limit [Formula: see text]. The results are compared with the theoretical calculations and the available experimental data.

scholarly journals (E)-1-(Benzo[d][1,3]dioxol-5-yl)-3-([2,2′-bithiophen]-5-yl)prop-2-en-1-one: crystal structure, UV–Vis analysis and theoretical studies of a new π-conjugated chalcone

2019 ◽  
Vol 75 (5) ◽  
pp. 632-637
Author(s):  
Ainizatul Husna Anizaim ◽  
Muhamad Fikri Zaini ◽  
Muhammad Adlan Laruna ◽  
Ibrahim Abdul Razak ◽  
Suhana Arshad
Keyword(s):  
Density Functional ◽  
Energy Gap ◽  
Weak Interactions ◽  
Basis Set ◽  
Molecular Orbital Calculations ◽  
Functional Theory ◽  
Compound C ◽  
Homo And Lumo ◽  
Experimental Values ◽  
Homo Lumo

In the title compound, C18H12O3S2, synthesized by the Claisen–Schmidt condensation method, the essentially planar chalcone unit adopts an s-cis configuration with respect to the carbonyl group within the ethylenic bridge. In the crystal, weak C—H...π interactions connect the molecules into zigzag chains along the b-axis direction. The molecular structure was optimized geometrically using Density Functional Theory (DFT) calculations at the B3LYP/6–311 G++(d,p) basis set level and compared with the experimental values. Molecular orbital calculations providing electron-density plots of HOMO and LUMO molecular orbitals and molecular electrostatic potentials (MEP) were also computed both with the DFT/B3LYP/6–311 G++(d,p) basis set. The experimental energy gap is 3.18 eV, whereas the theoretical HOMO–LUMO energy gap value is 2.73 eV. Hirshfeld surface analysis was used to further investigate the weak interactions present.

scholarly journals One-Dimensional Hydrogen-Bonded N–H…O in the Hybrid Phosphate: Hirshfeld Surface Analysis and DFT Quantum Chemical Calculations

2021 ◽  
Vol 15 (3) ◽  
pp. 359-368
Author(s):  
Abdellatif Rafik ◽  
◽  
Hafid Zouihri ◽  
Taoufiq Guedira ◽  
◽  
...  
Keyword(s):  
Surface Analysis ◽  
Density Functional ◽  
Energy Gap ◽  
Density Functional Theory Calculations ◽  
Hirshfeld Surface ◽  
Basis Set ◽  
Hirshfeld Surface Analysis ◽  
Supramolecular Network ◽  
Perfect Agreement ◽  
Molecular Electrostatic Potential Surface

In the present work the 3D-supramolecular network is stabilized by N–H…O and O–H…O hydrogen bonds, by O…N interactions involving the organic cation and inorganic anion as checked by Hirshfeld surface analysis. The van der Waals contacts play a key role in the consolidation of the packing of 4-chloro-2-methylanilinium dihydrogenphosphate[4-CMDHP] structure. In order to support experimental results, density functional theory calculations have been performed using B3LYP functional with 3-21 G basis set. All of the obtained theoretical results are in a perfect agreement with the experimental ones. Furthermore, nonlinear optical behavior of 4-CMDHP has been investigated by determining the Hirshfeld surface, density of states and HOMO-LUMO energy gap using the same basis set. Finally, the molecular electrostatic potential surface of 4-CMDHP molecule was simulated and discussed.

scholarly journals 4-(4,5-Diphenyl-1H-imidazole-2-yl)phenol: Synthesis and Estimation of Nonlinear Optical Properties using Z-Scan Technique and Quantum Mechanical Calculations

2021 ◽  
Vol 68 (1) ◽  
pp. 170-177
Author(s):  
Fatemeh Mostaghni
Keyword(s):  
Optical Properties ◽  
Dipole Moment ◽  
Title Compound ◽  
Nonlinear Optical ◽  
Energy Gap ◽  
Nbo Analysis ◽  
Nonlinear Optical Properties ◽  
Basis Set ◽  
Third Order ◽  
Theoretical Investigations

In this study, 4-(4,5-Diphenyl-1H-imidazole-2-yl) phenol is successfully synthesized, and its nonlinear optical properties (NLO) are investigated both experimentally and theoretically. Theoretical investigations have been done by using TDDFT and B3LYP functional with usual 6-31+G(d,p) basis set. The results of HOMO-LUMO and NBO analysis show the low energy gap, high total dipole moment, and hyperpolarizabilities (β, γ) as well as the presence of dipolar excited states with relatively significant dipole-moment changes which are linked to the nonlinearity. The z-scan technique confirmed the NLO properties of title compound. The nonlinear absorption coefficient, refractive index, and third-order susceptibility were found to be 4.044 × 10−1 cmW−1, 2.89 × 10−6 cm2W−1 and 2.2627 × 10−6 esu, respectively. The negative sign of n2 indicated the occurrence of self-defocusing nonlinearity. The results show that the title compound can been used as potential NLO material.

Investigating the Effect of Nitro Groups on the Electronic Properties of Phenanthrene Compound

2021 ◽  
Vol 14 (3) ◽  
pp. 221-230
Keyword(s):  
Fermi Level ◽  
Electronic Properties ◽  
Ionization Potential ◽  
Nitro Group ◽  
Density Functional ◽  
Energy Gap ◽  
Basis Set ◽  
Potential Surfaces ◽  
Homo And Lumo ◽  
Total Energies

Abstract: Theoretical study for calculating the electronic structure of phenanthrene compound and its simplest derivatives with nitro groups in different positions was performed using density functional theory (DFT) based on the hybrid function of three parameters. Lee-Yang-Parr [B3LYP] with 6-31 [d, p] basis set was used to investigate the effect of nitro groups on the electronic properties of phenanthrene compound. All calculations were obtaind by employing the used method using the Gaussian 09 package of programs. The energy gaps, total energies, the energy of HOMO and LUMO, softness, dipole moment, Fermi level, molecular symmetry, electrochemical hardness, electron density, electrostatic potential surfaces and infrared spectra were calculated. The results showed that the electronic properties of phenanthrene molecule are affected by the added nitro group. The total energy, energy gap and the HOMO and LUMO energy decreased compared with the original molecule. The ionization potential (IP), electron affinity (EA) and Fermi level (Ef) are increased compared with the original molecule. Keywords: B3LYP/DFT calculations, Phenanthrene molecule, Nitro group, Energy gap, Ionization potential.

scholarly journals Quantum chemical insight into molecular structure, spectroscopic and nonlinear optical studies on methylene bis(dithiobenzoate)-=SUP=-*-=/SUP=-

2021 ◽  
Vol 129 (9) ◽  
pp. 1136
Author(s):  
Davut Avci ◽  
Semiha Bahceli
Keyword(s):  
Title Compound ◽  
Quantum Chemical ◽  
Density Functional ◽  
Nonlinear Optical ◽  
Chemical Shifts ◽  
Basis Set ◽  
Spectral Studies ◽  
Nmr Chemical Shifts ◽  
Vis Spectroscopy ◽  
C Nmr

In this study, the methylene bis(dithiobenzoate) molecule, (C15H12S4), as a bioactive molecule has been subjected to quantum chemical computations using density functional theory (DFT) in order to investigate the molecular geometry, IR, UV-visible and NMR spectral studies. The title molecule has been optimized at the B3LYP, B3PW91 and PBE11PBE levels of DFT and 6-311G(d,p) basis set. Furthermore, the vibrational frequencies, the HOMO-LUMO energy levels, the 1H and 13C NMR chemical shifts (ppm), nonlinear optical properties calculations of the title compound were obtained by B3LYP, B3PW91 and PBE1PBE levels. The maximum electronic transition wavelengths, oscillator strengths, excited state and transition dipole moments for the title compound were also investigated by B3LYP, B3PW91 and PBE1PBE levels of time-dependent (TD)-DFT. Keywords: methylene bis(dithiobenzonoate), IR and UV-vis spectroscopy, 1H and 13C NMR chemical shifts, NLO DFT method.

Theoretical investigation on the geometric, spectroscopic, nonlinear optical parameter, and frontier molecular orbital of 1,3-bis(4-methoxyphenyl)prop-2-en-1-one by DFT/ab initio calculations

2013 ◽  
Vol 91 (12) ◽  
pp. 1225-1232 ◽  
Author(s):  
Xiao-Hong Li ◽  
Rui-Zhou Zhang ◽  
Xian-Zhou Zhang
Keyword(s):  
Ab Initio ◽  
Title Compound ◽  
Density Functional ◽  
Nonlinear Optical ◽  
Optical Parameter ◽  
Basis Set ◽  
Frontier Molecular Orbital ◽  
Chemical Hardness ◽  
Hartree Fock ◽  
The Difference

Quantum chemical calculations of energies, geometries, and vibrational wavenumbers of 1,3-bis(4-methoxyphenyl)prop-2-en-1-one (C17H16O3) in the ground state were carried out by the using ab initio Hartree−Fock and density functional theory (DFT/B3LYP) methods with the 6-311++G** basis set. The difference between the observed and scaled wavenumber values of most of the fundamentals is very small. Theoretical vibrational spectra of the title compound were interpreted by means of potential energies distributions. The theoretical spectrograms for IR spectra of the title compound have been constructed. The analysis of natural bond orbitals shows that the intramolecular hyperconjugative interactions are formed by the orbital overlap between π*(C–C) and π(C–C) bond orbitals, which results in intramolecular charge transfer causing stabilization of the system. The predicted nonlinear optical properties of the title compound are much larger than those of urea. In addition, the analysis of frontier molecular orbitals shows that the title compound has good stability and high chemical hardness.

scholarly journals Key Electronic, Linear and Nonlinear Optical Properties of Designed Disubstituted Quinoline with Carbazole Compounds

Molecules ◽  
2021 ◽  
Vol 26 (9) ◽  
pp. 2760
Author(s):  
Bakhat Ali ◽  
Muhammad Khalid ◽  
Sumreen Asim ◽  
Muhammad Usman Khan ◽  
Zahid Iqbal ◽  
...  
Keyword(s):  
Density Functional ◽  
Nonlinear Optical ◽  
Energy Gap ◽  
Photonic Devices ◽  
Vital Role ◽  
Structure Property ◽  
Functional Theory ◽  
Materials Development ◽  
Donor Acceptor ◽  
Experimental Values

Organic materials development, especially in terms of nonlinear optical (NLO) performance, has become progressively more significant owing to their rising and promising applications in potential photonic devices. Organic moieties such as carbazole and quinoline play a vital role in charge transfer applications in optoelectronics. This study reports and characterizes the donor–acceptor–donor–π–acceptor (D–A–D–π–A) configured novel designed compounds, namely, Q3D1–Q3D3, Q4D1–Q1D2, and Q5D1. We further analyze the structure–property relationship between the quinoline–carbazole compounds for which density functional theory (DFT) and time-dependent DFT (TDDFT) calculations were performed at the B3LYP/6-311G(d,p) level to obtain the optimized geometries, natural bonding orbital (NBO), NLO analysis, electronic properties, and absorption spectra of all mentioned compounds. The computed values of λmax, 364, 360, and 361 nm for Q3, Q4, and Q5 show good agreement of their experimental values: 349, 347, and 323 nm, respectively. The designed compounds (Q3D1–Q5D1) exhibited a smaller energy gap with a maximum redshift than the reference molecules (Q3–Q5), which govern their promising NLO behavior. The NBO evaluation revealed that the extended hyperconjugation stabilizes these systems and caused a promising NLO response. The dipole polarizabilities and hyperpolarizability (β) values of Q3D1–Q3D3, Q4D1-Q1D2, and Q5D1 exceed those of the reference Q3, Q4, and Q5 molecules. These data suggest that the NLO active compounds, Q3D1–Q3D3, Q4D1–Q1D2, and Q5D1, may find their place in future hi-tech optical devices.

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