scholarly journals Vibrational Spectroscopic Study of (E)-4-(Benzylideneamino)-N-Carbamimidoyl Benzenesulfonamide

2012 ◽  
Vol 2012 ◽  
pp. 1-11 ◽  
Author(s):  
Asha Chandran ◽  
Sheena Mary ◽  
Hema Tresa Varghese ◽  
C. Yohannan Panicker ◽  
T. K. Manojkumar ◽  
...  
Keyword(s):  
Fourier Transform ◽  
Potential Energy ◽  
Density Functional ◽  
Potential Energy Distribution ◽  
Geometrical Parameters ◽  
Functional Theory ◽  
Hartree Fock ◽  
The Fourier Transform ◽  
The Stability ◽  
Surface Scan

The Fourier transform infrared and Fourier transform Raman spectra of (E)-4-(benzylideneamino)-N-carbamimidoyl benzenesulfonamide were recorded and analyzed. Geometry and harmonic vibrational wavenumbers were calculated theoretically using Gaussian 03 set of quantum chemistry codes. Calculations were performed at the Hartree-Fock (HF) and density functional theory (DFT; B3PW91, B3LYP) levels of theory. The calculated wavenumbers (B3LYP) agree well with the observed wavenumbers. Potential energy distribution is done using GAR2PED program. The red shift of the N-H stretching band in the infrared spectrum from the computed wavenumber indicates the weakening of the N-H bond. The geometrical parameters of the title compound are in agreement with that of reported similar derivatives. The calculated first hyperpolarizability is comparable with the reported value of similar derivative and may be an attractive object for further studies of nonlinear optics. Potential energy surface scan studies have been carried out to understand the stability of planar and nonplanar structures of the molecule.

ENERGETICS AND STRUCTURAL INSIGHTS OF MOLECULAR CONDUCTORS USING DENSITY FUNCTIONAL THEORY METHODS: 1,3-DITHIOLE-2-THIONE, 1,3-DITHIOLE-2-ONE, 1,3-DIOXOLE-2-ONE, AND 1,3-DIOXOLE-2-THIONE

2009 ◽  
Vol 08 (06) ◽  
pp. 1185-1195 ◽  
Author(s):  
R. L. PRASAD ◽  
A. KUSHWAHA ◽  
RAJENDRA PRASAD ◽  
S. JAISWAL ◽  
R. A. YADAV
Keyword(s):  
Density Functional Theory ◽  
Density Functional ◽  
Energy Requirement ◽  
Radical Cations ◽  
Geometrical Parameters ◽  
Dft Methods ◽  
Molecular Conductors ◽  
Relaxation Energy ◽  
Functional Theory ◽  
Hartree Fock

Computations were carried out employing the restricted Hartree–Fock (RHF) and density functional theory (DFT) methods to investigate the geometries and energies for the 1,3-dithiole-2-thione (DTT), 1,3-dithiole-2-one (DTO), 1,3-dioxole-2-thione (DOT), and 1,3-dioxole-2-one (DOO) molecules and their radical cations. The geometrical parameters of all the four molecules suggest a finite extent of extended conjugation across the molecules. The radical cations of the DTT and DOT molecules exhibit increased extent of conjugation compared to their neutral analogues. However, on going from the neutral DOO and DTO molecules to their radical cations, the extent of conjugation across the ions decreases and two unsaturated sites become isolated from each other. Requirement of the relaxation energy for the formation of radical cation is much lower for the DTT and DOT molecules compared to that for the DOO and DTO molecules. Smaller relaxation energy requirement favors minimal resistance to charge transport along the molecular stacking. Therefore, it is speculated that the DTT and DOT molecules are better molecular conductors as compared to the DOO and DTO molecules.

scholarly journals Cooperativity of Three Fragments : Protonated or Methylated Makaluvamine, Water Molecule and Glutamic Acid Molecule in Twelve Complexes and their Stabilities. A Study Performed at B3LYP/6-31+G(D,P) Level

2020 ◽  
pp. 1-10
Author(s):  
Soleymane Koné ◽  
Sékou Diomandé ◽  
El-Hadji Sawaliho Bamba
Keyword(s):  
Water Molecule ◽  
Glutamic Acid ◽  
Density Functional ◽  
Topoisomerase Ii ◽  
Geometrical Parameters ◽  
Acid Molecule ◽  
Functional Theory ◽  
Cancer Breast ◽  
Total Interaction ◽  
The Stability

Makaluvamines are used by intercalation in the DNA for the treatment of cancer cells such as colon cancer, prostate cancer, breast cancer.... This work studies energetic and geometrical parameters of stability of the 3-body complexes formed by six Makaluvamines, first protonated and then methylated by interactions with a water molecule and a glutamic acid molecule (Glu. Ac), a protein residue of topoisomerase II. This study was carried out by the quantum chemistry method of density functional theory (DFT). Firstly, we determined the energy of each super-molecule, the energies of all units of two fragments and one fragment in the geometries of the complexes. We have also determined the energies of 2-body and 3-body interaction, cooperativity, relaxation and total interaction. The results of these calculations helped to appreciate the rigidity of each fragment between the isolated and complex states. They also allowed knowing the stability of each complex and the contribution of each interaction term to this stability.

scholarly journals Structure, Electronic And Vibrational Study of 7-Methyl-2,3-Dihydro-(1,3)Thiazolo(3,2-A) Pyrimidin-5-One by Using Density Functional Theory

2018 ◽  
Vol 22 (2) ◽  
pp. 1-11
Author(s):  
Bhawani Datt Joshi ◽  
Janga Bahadur Khadka ◽  
Atamram Bhatt
Keyword(s):  
Density Functional Theory ◽  
Molecular Orbital ◽  
Density Functional ◽  
Basis Set ◽  
Orbital Energy ◽  
Potential Energy Distribution ◽  
Functional Theory ◽  
Hartree Fock ◽  
Solvent Phase ◽  
Lowest Unoccupied Molecular Orbital

 We have presented molecular structure and vibrational wavenumber assignments of 7-methyl-2,3-dihydro-(1,3)thiazolo(3,2-a)pyrimidin-5-one. Both ab initio Hartree-Fock and density functional theory employing 6-311++G(d,p) basis set have been used for the calculations. The scaled values of the calculated vibrational frequencies were used for assignments on the basis of potential energy distribution. The structure-activity relation has been interpreted by mapping molecular electrostatic potential surface. Electronic properties have been analyzed by using time dependent density functional theory (TD-DFT) for both gaseous and solvent phase. The calculated HOMO (highest occupied molecular orbital) and LUMO (lowest unoccupied molecular orbital) energy values show that the charge transfer occurs within the molecule. Journal of Institute of Science and TechnologyVolume 22, Issue 2, January 2018, Page: 1-11 

scholarly journals Structural, Vibrational, Quantum Chemical Calculations, Thermal and Antimicrobial Studies On Nitrate Salt Of 3-Nitroaniline

2021 ◽  
Author(s):  
Thangarasu S ◽  
Siva V ◽  
Asath Bahadur S ◽  
Athimoolam S
Keyword(s):  
Density Functional ◽  
Basis Set ◽  
Experimental Result ◽  
Frontier Molecular Orbital ◽  
Geometrical Parameters ◽  
Functional Theory ◽  
Hartree Fock ◽  
Antimicrobial Studies ◽  
Evaporation Technique ◽  
Homo Lumo

Abstract In this work, 3-nitroanilinium nitrate (3NAN) has been synthesized and crystallized successfully by solution growth combined with solvent evaporation technique. 3NAN molecular structure has been optimized with Density Functional Theory (DFT) using B3LYP function and Hartree-Fock method with a 6-311 + + G(d,p) basis set. The geometrical parameters of the title molecules have been analyzed. The computed vibrational spectra were compared with experimental result which show appreciable agreement. Thermal stability of the crystal was analyzed with TGA/DTA and the melting points of the salt identified at 209 ºC. HOMO-LUMO energy calculations have shown the charge transfer within the molecu le. The possible pharmaceutical/biological activity of the salts confirmed by the Frontier Molecular Orbital (FMO) analysis have lower band gap value. The antimicrobial activity of grown crystals were tested against certain potentially threatening microbes.

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.

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