scholarly journals Theoretical Studies of Structure, Spectroscopy, and Properties of a New Hydrazine Derivative

2013 ◽  
Vol 2013 ◽  
pp. 1-6 ◽  
Author(s):  
Hajar Sahebalzamani ◽  
Farshid Salimi ◽  
Elmira Dornapour
Keyword(s):  
Ground State ◽  
Theoretical Study ◽  
Molecular Geometry ◽  
Vibrational Frequencies ◽  
Basis Sets ◽  
Theoretical Studies ◽  
Hydrazine Derivative ◽  
Homo And Lumo ◽  
Good Agreement ◽  
Ft Raman

We will report a combined experimental and theoretical study on molecular structure, vibrational spectra, and energies of (E)-1-(2,4-dinitrophenyl)-2-[(4-methylphenyl)methylidene]hydrazine (1). The molecular geometry and vibrational frequencies and energies in the ground state are calculated by using HF and DFT levels of theory with 6-311G basis sets. The calculated HOMO and LUMO energies also confirm that charge transfer occurs within the molecule. The harmonic vibrational frequencies were calculated, and the scaled values have been compared with experimental FTIR and FT-Raman spectra. The observed and the calculated frequencies are found to be in good agreement. The experimental spectra also coincide satisfactorily with those of theoretically constructed bar-type spectrograms.

scholarly journals Synthesis, characterization and theoretical calculations of Cu(I) complex of trithiocyanuric acid [Cu(ttc)3]

2018 ◽  
Vol 23 (2) ◽  
pp. 241-266 ◽  
Author(s):  
Ximena Verónica Jaramillo-Fierro ◽  
César Zambrano ◽  
Francisco Fernández ◽  
Regino Saenz-Puche ◽  
César Costa ◽  
...  
Keyword(s):  
Computational Study ◽  
Theoretical Calculations ◽  
Photophysical Properties ◽  
Vibrational Frequencies ◽  
Basis Sets ◽  
Vertical Excitation ◽  
Experimental Values ◽  
Homo Lumo ◽  
Perchlorate Hexahydrate ◽  
Good Agreement

A new Cu(I) complex constructed by reaction of trithiocyanuric acid (ttc) and copper (II) perchlorate hexahydrate has been successfully synthesized by a slow sedimentation method in a DMF solvent at room temperature. The molecular structure of the compound was elucidated by MALDI-TOFMS, UV Vis and FTIR spectroscopy, DSC-TGA analysis and magnetic susceptibility measurement. The proposed structure was corroborated by a computational study carried out with the Gaussian09 and AIMAII programs using the RB3LYP hybrid DFT functional with both 6-31G and Alhrich-TZV basis sets. The calculated vibrational frequencies values were compared with experimental FTIR values. Photophysical properties of the synthesized complex were evaluated by UV-Visible spectroscopy and compared with computed vertical excitation obtained from TDDFT. The theoretical vibrational frequencies and the UV Vis spectra are in good agreement with the experimental values. Additionally, the Frontier Molecular Orbitals (HOMO-LUMO) and the Molecular Electrostatic Potential of the complex was calculated using same theoretical approximation. The results showed the interaction between three coordinatedl igand atoms and the Cu(I) ion.

RELATIONSHIPS BETWEEN DIFFERENT-ORDER POLARIZABILITIES AND GROUND STATE DIPOLE MOMENT

2013 ◽  
Vol 12 (01) ◽  
pp. 1250099 ◽  
Author(s):  
K. HATUA ◽  
PRASANTA K. NANDI
Keyword(s):  
Dipole Moment ◽  
Ground State ◽  
Rational Design ◽  
Theoretical Study ◽  
Basis Sets ◽  
Ground State Dipole Moment ◽  
Donor Acceptor ◽  
Equilibrium Structures ◽  
Different Order ◽  
Different Levels

A number of charge transferring molecules with varying electron donor, acceptor and π-conjugative paths have been considered for the theoretical study of their NLO properties in terms of the linear polarizability and the ground state dipole moment. The equilibrium structures are calculated at the HF, MP2 and B3LYP levels, respectively. The longitudinal components of NLO coefficients are calculated by using HF, MP2, B3LYP, BHHLYP, CAM-B3LYP, and wB97XD methods for 6-31+G(p,d) and 6-311++G(p,d) basis sets. The hyperpolarizabilities obtained at different levels of calculation showed a fairly consistent trend. The relationships between hyperpolarizabilities, polarizability and ground state dipole moment have been proposed by considering only the two-level term in the standard sum-over-state (SOS) expressions and the generalized Thomas–Kuhn (TK) sum rule. The ab initio calculated first- and second-hyperpolarizabilities fairly correlate with the reduced 2-level contributions relating to the linear polarizability and ground state dipole moment. For a given length of conjugation the stronger enhancement of cubic polarizability arises from the increase of quadratic polarizability for comparable values of linear polarizability and dipole moment. The idea developed in the present work can be used to make a rational design of potential NLO-phores.

scholarly journals Optimized Geometry, Charge Distributions, Frontier Molecular Orbital Analysis and NLO Efficiency of BIS (4-Methoxyanilinium) Adipate by Quantum Chemical Calculations

2019 ◽  
Vol 9 (1S3) ◽  
pp. 329-340
Keyword(s):  
Charge Transfer ◽  
Quantum Chemical ◽  
Molecular Geometry ◽  
Basis Sets ◽  
Frontier Molecular Orbital ◽  
Mulliken Charge ◽  
Quantum Chemical Analysis ◽  
Molecular Orbital Analysis ◽  
Orbital Analysis ◽  
Good Agreement

In this work, optimized molecular geometry, vibrational and electronic properties of Bis(4-methoxylanilinium) adipate (4MAA) was obtained by Quantum chemical analysis using 6-311++G(d,p) basis sets. The experimental and computation vibrational spectra have been discussed. Experimental spectra of the 4MAA were recorded in the region 4000–400 cm-1 . The experimental and computational assignments were found to be in good agreement. FMO energies showed that charge transfer had occurred within the molecule. Mulliken charge distribution of the present compound was studied systematically. Furthermore, the hyperpolarizability calculations were analyzed.

scholarly journals DFT and Molecular Docking Study of 2-[2-(4-Chlorophenylaminothiazol-5-yl]benzothiazole

2019 ◽  
Vol 31 (3) ◽  
pp. 695-698
Author(s):  
N.S. Femila Nirmal ◽  
T.F. Abbs Fen Reji
Keyword(s):  
Molecular Docking ◽  
Atomic Charge ◽  
Molecular Geometry ◽  
Docking Study ◽  
Vibrational Frequencies ◽  
Molecular Docking Study ◽  
B3lyp Method ◽  
Homo And Lumo ◽  
Charge Analysis ◽  
Vibrational Bands

The title compound was computed by means of DFT chemical quantum calculations to obtain optimized molecular geometry, harmonic vibrational frequencies and atomic charges. Vibrational bands to the various structural groups and their importance were predicted by analyzing the vibrational spectra. The data showed that B3LYP method provide satisfactory data for assigning vibrational frequencies and structural properties.The HOMO and LUMO energies calculated permit the determination of atomic and molecular parameters and they also represented the transfer of charge in the molecule. Mulliken atomic charge analysis was also done. A comprehensive molecular picture of 2-[2-(4-chlorophenylaminothiazol-5-yl]benzothiazole and its interactions were got from NBO investigations. The molecular docking study indicates that benzothiazole derivative may possess inhibitory activity against BCL2 pancreatic cancer cell lines.

Theoretical Study of the Physisorption of CO on Metal Oxide Surfaces Using the KSCED-DFT Approach

1998 ◽  
Vol 63 (9) ◽  
pp. 1447-1459 ◽  
Author(s):  
Nathalie Vulliermet ◽  
Tomasz A. Wesolowski ◽  
Jacques Weber
Keyword(s):  
Metal Oxide ◽  
Frequency Shift ◽  
Electron Density ◽  
Effective Potential ◽  
Theoretical Study ◽  
Adsorbed Molecule ◽  
Theoretical Studies ◽  
Metal Oxide Surfaces ◽  
Stretching Vibration ◽  
Good Agreement

Theoretical studies on structure and stretching frequency of the CO molecule physisorbed on the MgO(100) or ZnO(1010) surfaces are reported. The properties of the adsorbed molecule were investigated by means of the recently developed formalism of Kohn-Sham equations with constrained electron density (KSCED). The KSCED method makes it possible to divide a large system into two subsystems and to study one of them using Kohn-Sham-like equations with an effective potential which takes into account the interactions between subsystems. This method (KSCED) was shown to be adequate to study the properties of the CO molecule adsorbed on the MgO(100) surface as reported in a previous paper (Wesolowski et. al.: J. Mol. Struct., THEOCHEM, in press). The effect of the interactions with the surface on the CO stretching frequency and geometry was analyzed for vertically bound (C-down) CO at the Zn-site of the ZnO(1010) surface. The ZnO(1010) surface was represented using several cluster models: Zn2+, (ZnO3)4-, or Zn9O9 embedded in a matrix of point charges. The KSCED frequency shift of the CO stretching vibration is blue-shifted and in good agreement with experiment.

Theoretical Study of Density Function Theory on Excited States of Methyl Methacrylate

2011 ◽  
Vol 233-235 ◽  
pp. 2871-2874
Author(s):  
Zhi Xong Huang ◽  
Gang Qin ◽  
Ming Zhang ◽  
Yan Qin ◽  
Lian Meng Zhang
Keyword(s):  
Excited State ◽  
Methyl Methacrylate ◽  
Excitation Energy ◽  
Excited States ◽  
Ground State ◽  
Theoretical Study ◽  
Function Theory ◽  
Density Function Theory ◽  
Molecular Structures ◽  
Homo And Lumo

The excited states of methyl methacrylate(MMA) were calculated by CIS method, MMA molecules on the ground and excited states of molecular structures were optimized. The HOMO and LUMO molecular orbitals of MMA molecule are given in the ground state and excited state . The results show that: MMA is excited, the molecular orbital from 27 → 28, the excitation energy is 1.4310eV, Carbon-carbon（C=C）double bonds break.

FTIR, FTR Spectral Analysis and DFT Calculations of 1, 8-Dimethyl Naphthalene

2012 ◽  
Vol 584 ◽  
pp. 371-375
Author(s):  
V. Pouchaname ◽  
R. Madivanane ◽  
A. Tinabaye
Keyword(s):  
Spectral Analysis ◽  
Dft Calculations ◽  
Raman Spectra ◽  
Solid Phase ◽  
Computational Method ◽  
Basis Sets ◽  
Vibrational Modes ◽  
Normal Coordinate ◽  
Good Agreement ◽  
Ft Raman

ABSTRACT. Solid phase FTIR and FT-Raman spectra of 1, 8-dimethylnaphthalene have been recorded in the region 3700-50 cm-1. The spectra were interpreted with aid of normal coordinate analysis based on DFT using standard B3LYP/6-31G basis sets. After scaling there is good agreement between observed and calculated frequencies. Comparison of the simulated spectra with the experimental spectra provides important information about the ability of the computational method to describe the vibrational modes.

scholarly journals Comparative experimental and theoretical study on the molecular structure and spectroscopic properties of sideroxol isolated from Sideritis stricta and its electronic properties

2021 ◽  
Vol 9 (2) ◽  
pp. 94-107
Author(s):  
Akin Azizoglu ◽  
◽  
Zuleyha Ozer ◽  
Carikci Sema ◽  
Turgut Kilic ◽  
...  
Keyword(s):  
Density Functional ◽  
Theoretical Study ◽  
Chemical Shifts ◽  
Molecular Geometry ◽  
Spectroscopic Properties ◽  
Basis Set ◽  
Basis Sets ◽  
Polarization Functions ◽  
Nmr Properties ◽  
Theory And Experiments

Sideroxol, a kaurene diterpene, was obtained from the acetone extract of Sideritis stricta plant. The ground-state molecular geometry, vibrational frequencies, and NMR chemical shifts were also investigated by using various density functional theories and Pople basis sets. The computed geometries are in good conformity with the experimental data. The comparison between theory and experiments indicates that B3LYP and M06 methods with the 6-31G(d) basis set are able to provide satisfactory results for predicting vibrational and NMR properties. There seems to be no significant effect of addition of diffuse and polarization functions in the basis set used herein.

scholarly journals Supramolecular study, Hirshfeld analysis and theoretical study of 6-methoxyquinolineN-oxide dihydrate

2013 ◽  
Vol 69 (6) ◽  
pp. 665-670 ◽  
Author(s):  
Rodolfo Moreno-Fuquen ◽  
Geraldine Hernandez ◽  
Alan R. Kennedy ◽  
Catriona A. Morrison
Keyword(s):  
Density Functional ◽  
Theoretical Study ◽  
Basis Sets ◽  
Water Molecules ◽  
Theoretical Studies ◽  
Functional Theory ◽  
Hartree Fock ◽  
Hirshfeld Surfaces ◽  
Hirshfeld Analysis ◽  
Oxide Group

In the crystal structure of 6-methoxyquinolineN-oxide dihydrate, C10H9NO2·2H2O, (I), the presence of two-dimensional water networks is analysed. The water molecules form unusual water channels, as well as two intersecting mutually perpendicular columns. In one of these channels, the O atom of theN-oxide group acts as a bridge between the water molecules. The other channel is formed exclusively by water molecules. Confirmation of the molecular packing was performed through the analysis of Hirshfeld surfaces, and (I) is compared with other similar isoquinoline systems. Calculations of bond lengths and angles by the Hartree–Fock method or by density functional theory B3LYP, both with 6-311++G(d,p) basis sets, are reported, together with the results of additional IR, UV–Vis and theoretical studies.

The electronic states and magnetization of coupled AlGaAs/GaAs quantum dots in magnetic fields

2018 ◽  
Vol 32 (02) ◽  
pp. 1850011 ◽  
Author(s):  
Eshtiaq Hijaz ◽  
Mohammad K. Elsaid
Keyword(s):  
Magnetic Field ◽  
Quantum Dots ◽  
Ground State ◽  
Theoretical Study ◽  
Electronic States ◽  
Exact Diagonalization ◽  
Interacting Electrons ◽  
Diagonalization Method ◽  
Exact Diagonalization Method ◽  
Good Agreement

We present a theoretical study of electronic states and magnetization of two interacting electrons confined in coupled quantum dots (CQDs) presented in a magnetic field. We obtain the eigenenergies of the CQD by solving the relative two-dimensional (2D) Hamiltonian using the combined variational–exact diagonalization method. The dependence of magnetization on temperature, magnetic field strength, confining frequency and barrier height has been investigated. We have shown the singlet–triplet transitions in the ground state of the CQD spectra and the corresponding jumps in the magnetization curves. The comparisons show that our results are in very good agreement with the reported works.

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