scholarly journals Ultrasound Assisted Synthesis, Molecular Structure,UV-Visible Assignments, MEP and Mulliken Charges Study of (E)-3-(4-chlorophenyl)-1-(4-methoxyphenyl) prop-2-en-1-one: Experimental and DFT Correlational

2021 ◽  
Vol 18 (1) ◽  
pp. 86-96
Author(s):  
Rohit S. Shinde
Keyword(s):  
Density Functional Theory ◽  
Density Functional ◽  
Density Functional Theory Method ◽  
Atomic Charge ◽  
Dft Method ◽  
Basis Set ◽  
Geometrical Parameters ◽  
Functional Theory ◽  
Vibrational Assignments ◽  
Uv Visible

Present investigation deals with the synthesis and density functional theory study (DFT) of a chalcone derivative; (E)-3-(4-chlorophenyl)-1-(4-methoxyphenyl)prop-2-en-1-one (CPMPP). The synthesis of a CPMPP has been carried out by the reaction of 4-methoxyacetophenone and 4-chlorobenzalehyde in ethanol at 30 ℃ under ultrasound irradiation. The structure of a synthesized chalcone is affirmed on the basis of FT-IT, 1H NMR and 13C NMR. The geometry of a CPMPP is optimized by using the density functional theory method at the B3LYP/6-31G(d,p) basis set. The optimized geometrical parameters like bond length and bond angles have been computed. The absorption energies, oscillator strength, and electronic transitions have been derived at the TD-DFT method at the B3LYP/6-31G(d,p) level of theory for B3LYP/6-31G(d p) optimized geometries. The effect of polarity on the absorption energies is discussed by computing UV-visible results in dichloromethane (DCM). Since theoretically obtained wavenumbers are typically higher than experimental wavenumbers, computed wavenumbers were scaled with a scaling factor, and vibrational assignments were made by comparing experimental wavenumbers to scaled theoretical wavenumbers. Quantum chemical parameters have been determined and examined. Molecular electrostatic potential (MEP) surface plot analysis has been carried out at the same level of theory. Mulliken atomic charge study is also discussed in the present study.

scholarly journals DFT Exploration on Molecular Characteristics of 6-Methyl-2-oxo-4-phenyl-1,2,3,4-tetrahydropyrimidine-5-carboxylate

2021 ◽  
Vol 7 (1) ◽  
pp. 717-720
Author(s):  
Abhijit R. Bukane ◽  
Bapu S. Jagdale
Keyword(s):  
Density Functional Theory ◽  
Density Functional ◽  
Sulfamic Acid ◽  
Density Functional Theory Method ◽  
Atomic Charge ◽  
Catalytic Amount ◽  
Basis Set ◽  
Molecular Characteristics ◽  
Geometrical Parameters ◽  
Functional Theory

Present investigation deals with the synthesis and density functional theory study (DFT) of a Biginelli adduct; 6-methyl-2-oxo-4-phenyl-1,2,3,4-tetrahydropyrimidine-5-carboxylate (MOPTHPC). The synthesis of a MOPTHPC has been carried out by the reaction of benzaldehyde, ethyl acetoacetate and urea in ethanol 70-80 ℃ under stirring condition in presence of catalytic amount of sulfamic acid. The structure of a synthesized chalcone is affirmed on the basis of 1H NMR and 13C NMR. The geometry of a MOPTHPC is optimized by using the density functional theory method at the B3LYP/6-311G(d,p) basis set. The optimized geometrical parameters like bond length and bond angles have been computed. Quantum chemical parameters have been determined and examined. Molecular electrostatic surface potential (MESP) surface plot analysis has been carried out at the same level of theory. Mulliken atomic charge study is also discussed in the present study.

scholarly journals Molecular Structures and Spectral Properties of Natural Indigo and Indirubin: Experimental and DFT Studies

Molecules ◽  
2019 ◽  
Vol 24 (21) ◽  
pp. 3831 ◽  
Author(s):  
Zixin Ju ◽  
Jie Sun ◽  
Yanping Liu
Keyword(s):  
Density Functional Theory ◽  
Spectral Properties ◽  
Density Functional ◽  
Dft Method ◽  
Molecular Structures ◽  
Basis Set ◽  
Frontier Molecular Orbital ◽  
Visible Absorption ◽  
Functional Theory ◽  
Uv Visible

This paper presents a comparative study on natural indigo and indirubin in terms of molecular structures and spectral properties by using both computational and experimental methods. The spectral properties were analyzed with Fourier transform infrared (FTIR), Raman, UV-Visible, and fluorescence techniques. The density functional theory (DFT) method with B3LYP using 6-311G(d,p) basis set was utilized to obtain their optimized geometric structures and calculate the molecular electrostatic potential, frontier molecular orbitals, FTIR, and Raman spectra. The single-excitation configuration interaction (CIS), time-dependent density functional theory (TD-DFT), and polarization continuum model (PCM) were used to optimize the excited state structure and calculate the UV-Visible absorption and fluorescence spectra of the two molecules at B3LYP/6-311G(d,p) level. The results showed that all computational spectra agreed well with the experimental results. It was found that the same vibrational mode presents a lower frequency in indigo than that in indirubin. The frontier molecular orbital analysis demonstrated that the UV-Visible absorption and fluorescence bands of indigo and indirubin are mainly derived from π → π* transition. The results also implied that the indigo molecule is more conjugated and planar than indirubin, thereby exhibiting a longer maximum absorption wavelength and stronger fluorescence peak.

Conformational and Vibrational Analysis of 2,4-, 2,5- and 2,6-Difluorobenzaldehydes by ab initio Hartree-Fock and Density Functional Theory Calculations

2008 ◽  
Vol 63 (3-4) ◽  
pp. 175-182 ◽  
Author(s):  
Adnan Sağlam ◽  
Fatih Ucun
Keyword(s):  
Density Functional Theory ◽  
Ab Initio ◽  
Density Functional ◽  
Vibrational Analysis ◽  
Molecular Structures ◽  
Basis Set ◽  
Functional Theory ◽  
Vibrational Assignments ◽  
Hartree Fock ◽  
The Mean

The optimized molecular structures, vibrational frequencies and corresponding vibrational assignments of the two planar O-cis and O-trans rotomers of 2,4-, 2,5- and 2,6-difluorobenzaldehyde have been calculated using ab initio Hartree-Fock (HF) and density functional theory (B3LYP) methods with the 6-311++G(d,p) basis set level. The calculations were adapted to the CS symmetries of all the molecules. The O-trans rotomers with lower energy of all the compounds have been found as preferential rotomers in the ground state. The mean vibrational deviations between the vibrational frequency values of the two conformers of all the compounds have been shown to increase while the relative energies increase, and so it has been concluded that the higher the relative energy between the two conformers the bigger is the mean vibrational deviation.

scholarly journals INVESTIGATION OF MOLECULAR STRUCTURE AND EXPERIMENTAL AND THEORETICAL SPECTROSCOPIC STUDIES OF ANTICANCER DRUGS - A REVIEW

2016 ◽  
Vol 38 (2) ◽  
pp. 1124
Author(s):  
Ashraf Sadat Ghasemi ◽  
Mahsan Deilam ◽  
Fereydoun Ashrafi
Keyword(s):  
Molecular Structure ◽  
Density Functional Theory ◽  
Anticancer Drugs ◽  
Density Functional ◽  
Computational Study ◽  
Molecular Geometry ◽  
Dft Method ◽  
Spectroscopic Studies ◽  
Functional Theory ◽  
Vibrational Assignments

In many literatures, both experimental and computational study on molecular structure and spectroscopic assignments of anticancer drugs has been reported. The molecular geometry was obtained from the X-ray structure determination exprimentally and optimized using computational chemistry methods like Density Functional Theory (DFT) method. In this review, we have investigated calculations based on density functional theory at the B3LYP/6-31G(d,p) and B3LYP/6-311++G(d,p) levels of theory. From the optimized geometry of the molecules, Molecular structure (bond lengths, bond angles and torsion angles) and vibrational assignments have been obtained.

scholarly journals Raman Spectroscopy Of Fullerene-Like Molecules Of Silicon Dioxide (SiO2)N(H2O)N/2

2016 ◽  
Vol 17 (3) ◽  
pp. 401-406
Author(s):  
O.V. Filonenko
Keyword(s):  
Density Functional Theory ◽  
Raman Spectroscopy ◽  
Silicon Dioxide ◽  
Density Functional ◽  
Density Functional Theory Method ◽  
Basis Set ◽  
Theory Method ◽  
Cyclic Structure ◽  
Functional Theory ◽  
Exchange Correlation

The Raman spectra of monosilicic, disilicic acid molecules, tetra- and pentasilicic acid molecules with cyclic structure, cage-like okta- and dekasilicic asid molecules, and of fullerene-like molecule (SiO2)N(H2O)N/2 have been calculated using density functional theory method (exchange-correlation functional B3LYP and basis set 6-31G (d, p)) and assignment of frequencies in conformity with the shape fluctuations have been executed.

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.

Basis Set Effects in Density Functional Theory Calculation of Muoniated Cytosine Nucleobase

2020 ◽  
Vol 860 ◽  
pp. 282-287
Author(s):  
Wan Nurfadhilah Zaharim ◽  
Shukri Sulaiman ◽  
Saidah Sakinah Mohd Tajudin ◽  
Siti Nuramira Abu Bakar ◽  
Nur Eliana Ismail ◽  
...  
Keyword(s):  
Density Functional Theory ◽  
Total Energy ◽  
Density Functional ◽  
Density Functional Theory Calculation ◽  
Geometry Optimization ◽  
Density Functional Theory Method ◽  
Basis Set ◽  
Basis Sets ◽  
Functional Theory ◽  
Muonium Hyperfine

The Density Functional Theory method was employed to investigate the electronic structure and muonium hyperfine interaction of muonium trapped near carbon atom labelled as '5' in cytosine nucleobase. Eighteen different basis sets in combination with B3LYP functional were examined in geometry optimization calculations on the muoniated radical. There are significant quantitative differences in the calculated total energy. The employment of basis set that does not include polarization function produces an optimized structure with high total energy. The 6-311++G(d,p) basis set yielded the lowest total energy as compared to other basis sets. The bond order of muonium trapped at C5 atom is in the range of 0.841 to 0.862. The 6-31G basis set produced the muonium Fermi contact coupling constant that is the closest to the experimental value.

An experimental and theoretical study on siderol isolated from Sideritis species

2011 ◽  
Vol 76 (2) ◽  
pp. 95-114 ◽  
Author(s):  
Akin Azizoglu ◽  
Zuleyha Özer ◽  
Turgut Kiliç
Keyword(s):  
Density Functional ◽  
Solid Phase ◽  
Basis Set ◽  
Geometrical Parameters ◽  
Functional Theory ◽  
Vibrational Assignments ◽  
Aerial Parts ◽  
Functional Methods ◽  
The Fourier Transform ◽  
Nmr Properties

The Fourier transform infrared (FTIR) spectrum of siderol, extracted from the aerial parts of Sideritis Gülendamii, has been measured in the range 4000–400 cm–1. Vibrational assignments and analyses of the fundamental modes of siderol were performed using the observed FTIR data recorded in the solid phase. The vibrational frequencies determined experimentally are compared with those obtained theoretically from density functional theory (DFT) and Hartee–Fock (HF) calculations. Optimized geometrical parameters of the title compound are in agreement with similar reported structures. The 1H and 13C NMR spectra of siderol have also been calculated by means of DFT and HF methods. The comparison between the experimental and the theoretical results indicates that density functional methods, B3LYP and MPW1PW91 with 6-31G(d) basis set, are able to provide satisfactory results for predicting NMR properties. On the basis of vibrational analyses, the thermodynamic properties of the title molecule have also been computed.

scholarly journals Crystal structure, spectroscopic characterization and DFT study of two new linear fused-ring chalcones

2018 ◽  
Vol 74 (10) ◽  
pp. 1427-1432 ◽  
Author(s):  
Dian Alwani Zainuri ◽  
Ibrahim Abdul Razak ◽  
Suhana Arshad
Keyword(s):  
Density Functional Theory ◽  
Density Functional ◽  
Crystal Packing ◽  
Molecular Geometry ◽  
Spectroscopic Characterization ◽  
Basis Set ◽  
Geometrical Parameters ◽  
Excitation Energies ◽  
Functional Theory ◽  
Experimental Findings

The structures of two new anthracenyl chalcones, namely (E)-1-(anthracen-9-yl)-3-(4-nitrophenyl)prop-2-en-1-one, C23H15NO3, and (E)-1-(anthracen-9-yl)-3-(4-iodophenyl)prop-2-en-1-one, C23H15IO are reported. A structural comparative study between the two chalcones was performed and some effects on the geometrical parameters, such as planarity and dihedral angles, are described. The molecular geometry was determined by single-crystal X-ray diffraction, and density functional theory (DFT) at B3LYP with the 6–311++G(d,p) basis set was applied to optimize the ground-state geometry. In addition, intermolecular interactions responsible for the crystal packing were analysed. The electronic properties, such as excitation energies and HOMO–LUMO energies were calculated by time-dependent density functional theory (TD–DFT) and the results complement the experimental findings. The molecular electrostatic potential (MEP) was also investigated at the same level of theory in order to identify and quantify the possible reactive sites.

scholarly journals Synthesis, Molecular Structure, HOMO-LUMO, Chemical, Spectroscopic (UV-Vis and IR), Thermochemical Study of Ethyl 6-amino-5-cyano-2-methyl-4-(4-nitrophenyl)-4H-pyran-3-carboxylate: A DFT Exploration

2021 ◽  
Vol 18 (2) ◽  
pp. 179-189
Author(s):  
Vishnu A. Adole ◽  
Tejendra R. Rajput ◽  
Bapu S. Jagdale
Keyword(s):  
Density Functional Theory ◽  
Density Functional ◽  
Vibrational Analysis ◽  
Basis Set ◽  
Thermochemical Study ◽  
Contour Plot ◽  
Dft Methods ◽  
Functional Theory ◽  
Vibrational Assignments ◽  
Td Dft

The ethyl 6-amino-5-cyano-2-methyl-4-(4-nitrophenyl)-4H-pyran-3-carboxylate (ACNPPC) was synthesized using an environmentally friendly method and looked into in terms ofstructural, UV-visible, vibrational, and computational analysis. In the gaseous phase, calculations of the density functional theory (DFT) with B3LYP/6-311G(d,p) level were performed. Using Time-dependent density functional theory (TD-DFT) with the B3LYP/6-311G(d,p) basis set method, the HOMO and LUMO energies are calculated. For assessing electrophilic and nucleophilic reactive sites, the molecular electrostatic surface potential (MESP) and contour plot were plotted over the optimized structure. Using computed and experimental vibrational spectra, vibrational assignments were elucidated. To illustrate the charge density in the title compound, Mulliken atomic charges are disclosed. In addition, using vibrational analysis, some thermochemical functions have also been derived. Theoretical simulations have shown the best relationship with experimental results obtained with the B3LYP/6-311G(d,p) level of theory at the DFT and TD-DFT methods.

Sign in / Sign up

Export Citation Format

Share Document