Theoretical study on ultraviolet profile and chemical reactivity descriptors of fluorinated liquid crystals: Effect of end chain length and substituent

2018 ◽  
Vol 665 (1) ◽  
pp. 119-132 ◽  
Author(s):  
T. Jaison Jose ◽  
A. Simi ◽  
M. David Raju ◽  
P. Lakshmi Praveen
Author(s):  
Kouadio Valery Bohoussou ◽  
Anoubilé Bénié ◽  
Mamadou Guy-Richard Koné ◽  
N’guessan Yao Silvère Diki ◽  
Kafoumba Bamba ◽  
...  

In this work the formation of vinylphosphines was studied through the hydrophosphination reaction. The study aims to rationalize the stereoselectivity of these compounds using quantum DFT methods. This theoretical study of chemical reactivity was conducted at B3LYP/6-311 + G (d, p) level. Global chemical reactivity descriptors, stationary point energies and activation barriers were examined to foretell the relative stability of the stereoisomers formed. The various results obtained have revealed that the addition of arylphosphine to dihalogenoacetylene is stereospecific. The Trans form of vinylphosphines is more stable than the Cis form, when the substituent on phosphorus generates less or no π-conjugations. On the other hand, the Cis isomer is predominant when the aryl radical favors more π-conjugations. The theoretical results obtained are in agreement with the experimental results.


2021 ◽  
Vol 37 (4) ◽  
pp. 805-812
Author(s):  
Ahissandonatien Ehouman ◽  
Adjoumanirodrigue Kouakou ◽  
Fatogoma Diarrassouba ◽  
Hakim Abdel Aziz Ouattara ◽  
Paulin Marius Niamien

Our theoretical study of stability and reactivity was carried out on six (06) molecules of a series of pyrimidine tetrazole hybrids (PTH) substituted with H, F, Cl, Br, OCH3 and CH3 atoms and groups of atoms using the density function theory (DFT). Analysis of the thermodynamic formation quantities confirmed the formation and existence of the series of molecules studied. Quantum chemical calculations at the B3LYP / 6-311G (d, p) level of theory determined molecular descriptors. Global reactivity descriptors were also determined and analyzed. Thus, the results showed that the compound PTH_1 is the most stable, and PTH_5 is the most reactive and nucleophilic. Similarly, the compound PTH_4 is the most electrophilic. The analysis of the local descriptors and the boundary molecular orbitals allowed us to identify the preferred atoms for electrophilic and nucleophilic attacks.


2009 ◽  
Vol 113 (30) ◽  
pp. 8660-8667 ◽  
Author(s):  
Carlos Cárdenas ◽  
Nataly Rabi ◽  
Paul W. Ayers ◽  
Christophe Morell ◽  
Paula Jaramillo ◽  
...  

2017 ◽  
Vol 16 (08) ◽  
pp. 1750076 ◽  
Author(s):  
Alejandro Morales-Bayuelo

Currently, there is increasing interest in the potential of malaria inhibitors in Plasmodium falciparum activity. In this work, is propose a possible alternative to classifying 154 antimalarials, with P. falciparum activity. These antimalarials were synthesized by the Chibale’s group ( http://www.kellychibaleresearch.uct.ac.za/ ), with the goal of finding new insights on the binding pocket of the protein kinase PfPK5, PfPK7, PfCDPK1, PfCDPK4, PfMAP1, and PfPK6 of the malaria parasite. However, there is only information about crystallography of PfPK5 and PfPK7. The protein kinases PfCDPK1, PfCDPK4, PfMAP1, and PfPK6 were modeled using molecular homology. The validation used shows that our homology models can be an alternative for the protein kinases from P. falciparum, unknown today. The antimalarials were classified by taking into account the interactions in the hinge zone. These ligands bind to the kinase through the formation of one of two hydrogen bonds, with the backbone residues of the hinge region connecting the kinase N- and C-terminal loops. These interactions were supported by a reactivity chemistry analysis, using global chemical reactivity descriptors such as chemical potential, hardness, softness, electrophilicity, and the Fukui functions as local reactivity descriptors, within the Density Functional Theory (DFT) context.


2013 ◽  
Vol 2013 ◽  
pp. 1-8 ◽  
Author(s):  
Jorge Ignacio Martínez-Araya ◽  
Guillermo Salgado-Morán ◽  
Daniel Glossman-Mitnik

The M06 family of density functionals has been assessed for the calculation of the molecular structure and properties of the Naringin molecule. The chemical reactivity descriptors have been calculated through Conceptual DFT. The active sites for nucleophilic and electrophilic attacks have been chosen by relating them to the Fukui function indices and the dual descriptorf(2)(r). A comparison between the descriptors calculated through vertical energy values and those arising from the Koopmans' theorem approximation has been performed in order to check for the validity of the last procedure.


2017 ◽  
Vol 58 (4) ◽  
Author(s):  
Luis Humberto Mendoza Huizar

<p>In this work we have calculated global and local DFT reactivity descriptors for tartrazine at B3LYP/6-311++G (2d,2p) level. Global reactivity descriptors such as ionization energy, molecular hardness, electrophilicity, and total energies were calculated to evaluate the tartrazine reactivity in aqueous and gas conditions. Local reactivity was evaluated through the Fukui function. The influence of the solvent was taken into account with the PCM model. The results indicate that the solvation process modifies the reactivity descriptors values. From our results, it was found that an electrophilic attack allows a direct cleavage of the N=N bond. If a nucleophilic attack is considered as initial attack, it is necessary a second attack by free radicals or electrophiles to cleave the N=N bond. In the case of an initial attack by free radicals, tartrazine requires a subsequent nucleophilic attack to cleave the N=N bond.</p>


2019 ◽  
Vol 2019 ◽  
pp. 1-12
Author(s):  
Norma Flores-Holguín ◽  
Juan Frau ◽  
Daniel Glossman-Mitnik

Five density functionals, CAM-B3LYP, LC-ωHPBE, MN12SX, N12SX, and ωB97XD, in connection with the Def2TZVP basis set were assessed together with the SMD solvation model for the calculation of the molecular properties, chemical reactivities, and solubilities of some pigments derived from astaxanthin, β-cryptoxanthin, fucoxanthin, myxol, siphonaxanthin, siphonein, and zeaxanthin marine carotenoids in the presence of different solvents (hexane, methanol, ethanol, and water). All the chemical reactivity descriptors for the systems were calculated via conceptual density functional theory (CDFT). Finally, the potential bioavailability and druggability as well as the bioactivity scores for the marine carotenoid pigments were predicted through different methodologies already reported in the literature, which have been previously validated during the study of other natural products obtained from marine sources.


2020 ◽  
Vol 139 (3) ◽  
Author(s):  
Marco Franco-Pérez ◽  
Carlos A. Polanco-Ramírez ◽  
José L. Gázquez ◽  
Paul W. Ayers ◽  
Alberto Vela

2021 ◽  
Vol 24 (2) ◽  
pp. 1-8
Author(s):  
Amar Tuma Musa ◽  
◽  
Khalida Abaid ◽  

The theoretical study represents an essential preliminary stage for the start of any industry, as it gives a theoretical description of the properties of compounds (chemical, physical and biological properties)without conducting research to find out about this and the least cost. Through the theoretical study, we extract a clear picture of the chemical compounds before starting to manufacture them to know the extent of their impact on human health and their chemical and biological effectiveness. Using the Density Functional Theory (DFT/B3LYP) with base 6-311G,throughGaussian 09 program, the optimize geometry,(bond lengths, angles bond)and vibrational spectra was calculated of the benzimidazole derivatives [Carbenzim (CZM), Mebendazole (MBZ)].Through orbital charts of HOMO and LUMO to study electronic properties. The HOMO-LUMO gap was also evaluated for chemical reactivity and determination of global reactivity descriptors (Hardness (),Softness (S), Electrophilicity(), Chemical potential(),Electronegativity(χ))] that defines compunds effectiveness and the their biological activities. In addition, (QSAR) data has been used to develop relationships between biological activities and thermophysical properties of chemicals, through the Hyper Chem8.0programbyusingSemi-empirical(SE)method at the (PM3) level. The LOG P value was calculated, binding energy, Polarizability, hydration energy, surface area, and electrostatic potential energy difference of two level.


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