chemical calculation
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Author(s):  
D. V. Klenitsky ◽  
L. L. Gladkov ◽  
I. V. Vershilovskaya ◽  
D. V. Petrova ◽  
A. S. Semeikin ◽  
...  

2021 ◽  
Vol 104 (4) ◽  
pp. 21-29
Author(s):  
Zh.S. Nurmaganbetov ◽  
◽  
G.K. Mukusheva ◽  
Ye.V. Minayeva ◽  
D.M. Turdybekov ◽  
...  

The synthesis of some cytisine derivatives was carried out in the work. The article provides the data of quantum-chemical calculation and virtual screening of the alkaloid cytisine derivatives synthesized. At the same time, the reaction centers of the cytisine derivatives molecules were determined. In order to study the reactivity of the derivatives obtained (namely cinnamoylcytisine, lipoylcytisine, and cytisinylisoalantholactone) the quantum-chemical calculations were conducted to determine the energy and charge characteristics of the molecules. The results indicate a sufficient thermodynamic stability of the cinnamoylcytisine and lipoylcytisine molecules. The cytisinylisoalantholactone molecule is not stable according to the results of quantum chemical calculations. The data on the energy values of the frontier molecular orbitals show that, in general, all molecules exhibit electrophilic properties. A bioprediction was implemented using PASS (Prediction of Activity Spectra for Substances) as one of the most efficient and well-known computer program with the aim of detailed study and the probable establishment of the biological activity of the synthesized cytisine derivatives. Based on the results of virtual screening, promising types of alkaloid cytisine derivatives were identified, which are potential sources of original drugs


2021 ◽  
Author(s):  
Eniya Palaniyasan ◽  
Anbarasan Radhakrishnan ◽  
Shivaraj R. Maidur ◽  
Parutagouda Shankaragouda Patil ◽  
Kalyana Sundar Jeyaperumal

Abstract In this work, the authors have reported the synthesis, crystal structure, and physicochemical properties of new Indolium based nonlinear optical crystal of 2-(2-(4-(4-chloro) phenyl) vinyl)-1, 1, 3-trimethyl-1H-benzo[e] Indolium iodide. The title crystal was grown by slow evaporation technique using methanol as a solvent. The harvested crystal is subjected to the single-crystal X-ray diffraction study and found that the title crystal belongs to the monoclinic system with a space group of P21/n. The bandgap and optical window of the material are studied by UV-visible spectroscopic analysis, and the found values are 4.2 eV and 295-800 nm, respectively. The grown crystal is subjected to analyze the thermal stability and found that high-temperature stability value upto 264 oC and which is sufficient for industrial applications. Furthermore, the effect of temperature on the grown crystal dielectric properties such as dielectric constant and dielectric losses is investigated by impedance spectroscopic analysis. The molecular charge transfer on the material is studied from density functional theory. The various intermolecular interactions existence in the crystal is explored from Hirshfeld surface analysis. Finally, the Z-scan parameters expose that title crystal is a potential material for third-harmonic generation applications. The overall structural studies and functional properties disclose that the grown crystal is well suitable for harmonic generation applications.


2021 ◽  
Vol 30 (6) ◽  
pp. 586-605
Author(s):  
Satya Narayan Chaulia ◽  

Semi-empirical quantum chemical calculation was made to study the nucleophilicity of the ligand and to study the mode of bonding between the ligand and the metal ions. The natural atomic charge at different atomic sites of the ligand has been calculated along with the electrostatic potential map to predict the reactive sites for electrophilic and nucleophilic attack. The theoretical spectral data such as IR, NMR and electronic have been calculated and compared with the experimentally generated data.


Author(s):  
V. S. Soldatov ◽  
T. V. Bezyazychnaya ◽  
E. G. Kosandrovich

Based on the data of ab initio calculation of the structure of (RSO3)2Mg (H2O)18 and (RSO3Rb)2(H2O)16 clusters, which simulate the structure of swollen sulfostyrene ion exchangers in the corresponding ionic forms and a water cluster of comparable size, the numbers of water molecules directly bound to cations and their coordination numbers, including the oxygen atoms of the sulfonic groups linked to the cation, were calculated. It is shown that the first molecular layer around the magnesium ion is formed from water molecules with the highest binding energy with the cluster, and around the rubidium ion – from the molecules of the nearest environment with the lowest binding energies. This is explained by the fact that the transfer of water molecules from its volume to magnesium hydrate is energetically favorable, but not to rubidium hydrate. Therefore, the magnesium ion builds its hydrate mainly from water molecules with the highest binding energy in order to obtain the greatest energy gain, and the rubidium ion – from molecules with the lowest energy, which provides the smallest energy loss.


Author(s):  
V. A. Babkin ◽  
D. S. Andreev ◽  
E. S. Titova ◽  
A. V. Ignatov ◽  
R. O. Boldyrev ◽  
...  

In this work, we performed a quantum-chemical calculation of some epoxy molecules: 1,2-epoxy-butene, 1,2-epoxy-2-methylpropane, 1,2 epoxyethane by the density functional theory DFT. An optimized geometric and electronic structure of these compounds is obtained. It was found that the studied epoxides belong to the class of very weak СH-acids (pKa = 28-30).


Author(s):  
G.V. Belov

The experience in developing an algorithm and a program for the thermal-chemical calculation of the characteristics of a rocket engine is presented. The program is written in Julia. To calculate the equilibrium composition of combustion products the freely distributed library Ipopt is used. The program is interfaced to the database on thermodynamic properties of individual substances IVTANTERMO. For the convenience of processing, the information on thermodynamic properties is stored in two text files of a special form. The program has been developed using the simplest working process model according to which the flow is one-dimensional, the product flow is adiabatic, there are no friction losses, the product flow is equilibrium, and the speed of condensed particles is equal to the gas flow speed. Ratios for calculating the derivatives of composition, as well as equilibrium values of heat capacity and sound velocity are given. The text of the program can be used in the study process and can easily be adapted to more complex models of the rocket engine workflow. The calculation results obtained using the developed program are in good agreement with the results of TERRA calculations. The execution time of one calculation for a four-element fuel, which includes the determination of the combustion products characteristics in the chamber, the critical cross section and at the nozzle cross section, varies in the range of 3--5 s


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