scholarly journals Hyperpolarizability of 6-vertex carboranes quantum chemical study

2003 ◽  
Vol 1 (1) ◽  
pp. 1-9 ◽  
Author(s):  
Kyrill Suponitsky ◽  
Tatiana Timofeeva
Keyword(s):  
Dft Calculations ◽  
Quantum Chemical ◽  
Quantum Chemical Study ◽  
Calculated Data ◽  
Chemical Study ◽  
Relative Orientation ◽  
Basis Set ◽  
Basis Sets ◽  
First Hyperpolarizability ◽  
Bond Lengths

AbstractStructure and molecular first hyperpolarizability (β) of nitro-amino-substituted 6-vertex 1,6-carboranes are investigated by means of DFT calculations. The results obtained have revealed that the relative orientation of substituents with respect to the carborane cage influences bond lengths distribution in the cage, which leads to significant changes in the values of hyperpolarizabilities. Calculations with different basis sets have demonstrated that the value of β is not significantly affected by the choice of basis set. The calculated data shows that hyperpolarizability of carborane molecules substituted for carbon atoms is lower than when substituted for boron atoms. For latter molecule, the value of β is of the same order as that of para-nitroaniline molecule.

Metalcarbonyl analogues of annelated cyclooctatetraene and cyclodecapentaene derivatives with a planar core cycle: a quantum chemical study

2018 ◽  
Vol 20 (44) ◽  
pp. 27830-27837 ◽  
Author(s):  
Tatyana N. Gribanova ◽  
Ruslan M. Minyaev ◽  
Vladimir I. Minkin ◽  
Alexander I. Boldyrev
Keyword(s):  
Dft Calculations ◽  
Quantum Chemical ◽  
Quantum Chemical Study ◽  
Chemical Study

With the help of DFT calculations the possibility of stabilizing non-standard flat conformations of cyclooctatetraene and cyclodecapentaene by equatorially located metalcarbonyl substituents has been predicted.

Study on Pyrrole 4-Pyrazoline Derivatives: Experimental and Quantum Chemical Approaches

2016 ◽  
Vol 69 (6) ◽  
pp. 672 ◽  
Author(s):  
R. N. Singh ◽  
Poonam Rawat ◽  
Vikas Baboo
Keyword(s):  
Dft Calculations ◽  
13C Nmr ◽  
Quantum Chemical ◽  
Density Functional ◽  
Electronic Absorption Spectra ◽  
Quantum Chemical Study ◽  
Basis Set ◽  
Dft Methods ◽  
Pyrrole Derivatives ◽  
1H And 13C Nmr

As part of a study on pyrrole derivatives we report here a combined experimental and quantum chemical study of pyrrole 4-pyrazoline biheterocyclic derivatives. The structure of the synthesised compounds have been studied using experimental IR, UV, 1H and 13C NMR spectroscopic analyses along with density functional theory (DFT) calculations using the B3LYP functional with 6–311+G (d,p) basis set. The global, local reactivity, and thermodynamic parameters support the analysis. All the experimental vibrational bands have been discussed and assigned to normal modes on the basis of our calculations. In addition, the computed 1H and 13C NMR data, obtained by DFT calculations, are found to be in good agreement with the experimental data and serve as valuable tools in identifying the products. The vibrational analysis shows red shifts in vN–H and vC=O stretching vibrations as a result of dimer formation. The theoretical electronic absorption spectra have been calculated by using time dependent-DFT methods. The static first hyperpolarizability (β0) values for the synthesized pyrrole–pyrazoline derivatives 4A–D are calculated as 16.97 × 10–30, 47.64 × 10–30, 65.40 × 10–30, 65.39 × 10–30 esu, respectively, and increase from 4A to 4C as a result of the addition of an –NO2 acceptor in 4B and two –NO2 group acceptors in 4C. However, an additional –Cl group in 4D on the phenyl ring attached to the pyrazoline moiety does not result in a clear change from 4C. The calculated static and dynamic hyperpolarizability results show that the investigated molecules might be used as non-linear optical materials.

scholarly journals A QUANTUM CHEMICAL STUDY ON ELUCIDATION OF MOLECULAR STRUCTURE, ELECTRIC MOMENTS AND VIBRATIONAL ANALYSES OF BETA-DAMASCENONE AND ITS ISOMER- A COMPARATIVE STUDY

2020 ◽  
Vol 4 (10) ◽  
pp. 123-136
Author(s):  
Amarendra Kumar
Keyword(s):  
Dipole Moment ◽  
Electrostatic Potential ◽  
Quantum Chemical ◽  
Active Sites ◽  
Molecular Electrostatic Potential ◽  
Quantum Chemical Study ◽  
Vibrational Analysis ◽  
Chemical Study ◽  
Basis Sets ◽  
Potential Energy Distribution

A comparative, quantum chemical study on of energies, dipole moment and vibrational wavenumbers of trans- beta-Damascenone and cis-beta-Damscenone was carried out by using B3LYP methods with 6-311+G(d,p) and 6-311++G(d,p) basis sets. A complete vibrational analysis of both the compounds has been performed and assignments are made on the basis of potential energy distribution. The frontier orbitals and molecular electrostatic potential surface study has also been employed to understand the active sites of title compounds. The calculation of the IR spectra is not only important in order to confirm the validity of the simulations but it also allows additional insight into the molecular level of the system not accessible from experiment. Therefore, simulated IR and Raman spectra of the title compounds are also presented in this study. The structure activity relationship based on the study of frontier orbital gap, dipole moment data along with the molecular electrostatic potential map of the title compounds have been used to understand the active sites of the molecules.

scholarly journals Silicon-Doped Nanotube (Si-CNT) as Drug Delivery Nanocarrier for Osteoporosis Drug: Quantum Chemical Study

2021 ◽  
Author(s):  
Zaid Al-Sawaff ◽  
Fatma Kandemirli ◽  
Serap Senturk Dalgic
Keyword(s):  
Drug Delivery ◽  
Quantum Chemical ◽  
Active Sites ◽  
Quantum Chemical Study ◽  
Chemical Study ◽  
Basis Set ◽  
Drug Molecules ◽  
Spontaneous Interaction ◽  
Silicon Doped ◽  
Molecular Orbital Analysis

Abstract The aim of this study is to investigate the potential and capability of Si-CNT to detect and adsorb BMSF-BENZ ((4-bromo-7-methoxy-1-(2-methoxyethyl)-5-{[3-(methylsulfonyl)phenyl]methyl}-2-[4-(propane-2-))yl) phenyl]-1H-1,3-benzothiazole) molecular. For this purpose, we considered different configurations for adsorbing BMSF-BENZ drug on the surface of the Si-CNT nanocluster. All considered configurations are optimized using DFT theory at the 6-31G** basis set and B3LYP level of theory, and then from optimized structures, for each nanoparticle, we selected four stable models for the adsorption of BMSF-BENZ from (Br, N8, N9, N58, O35, O41 and S) active sites on the surface the selected nanoparticle. and Quantum theory of atoms in Molecular Analysis (QTAIM), and Molecular Orbital Analysis (MO) was also established. The calculated results indicate that the distance between nanocluster and drug from the N8 site is lower than from all other locations sites for all investigated nanoparticles, and adsorption of BMSF-BENZ from the N8 site is more favorable especially for the Si-CNT nanotube. The adsorption energy, hardness, softness, and fermi energy results reveal that the interaction of BMSF-BENZ with Si-CNT, is an encouraging adsorbent for this drug as Eads of BMSF-BENZ/Si-CNT complexes are (-5.15, -24.21, -8.22, -17.03, -13.16, -2.22, -12.70) kcal/mol in the gas phase. As well, the appropriate and spontaneous interaction between the BMSF-BENZ drug and Si-CNT nanoparticle was confirmed by investigating the quantum chemical molecular descriptors and solvation Gibbs free energies of all atoms. Si-CNT can be used as an amperometric sensor to detect the BMSF-BENZ drug molecule. Thus, we propose that the Si-CNT can be a promising candidate as a drug delivery vehicle for BMSF-BENZ drug molecules.

scholarly journals QUANTUM-CHEMICAL STUDY OF THE MECHANISM OF REACTION OF BENZOELACETHYLENE WITH DITIO- AND DISELENOMALONAMIDES

2020 ◽  
Vol 2020 (1) ◽  
pp. 127-135
Author(s):  
Elena Chirkina
Keyword(s):  
Quantum Chemical ◽  
Density Functional ◽  
Quantum Chemical Study ◽  
Chemical Study ◽  
Polarizable Continuum Model ◽  
Basis Set ◽  
Mechanism Of Reaction ◽  
The Density Functional Theory ◽  
Two Stages ◽  
Polarizable Continuum

A mechanism of the interaction of benzoylacetylene with dithio- and diselenomalonamides has been proposed on the basis of quantum-chemical calculations in the framework of the density functional theory using the B3LYP/6-311++G(d,p) basis set taking into account solvent effects (AcOH) within the polarizable continuum model, PCM, with inclusion of the HCl molecule in the calculated space. It is shown that the reaction involves two stages to afford heterocyclic compounds of the dithiine and diselenine type

A quantum chemical study of the acidity of acetylene and 1,2-dihydrobuckminsterfullerene de-rivatives

2018 ◽  
Vol 59 (1) ◽  
pp. 51-53
Author(s):  
M. V. Makarova ◽  
◽  
S. G. Semenov ◽  
R. R. Kostikov ◽  
◽  
...  
Keyword(s):  
Quantum Chemical ◽  
Quantum Chemical Study ◽  
Chemical Study
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