scholarly journals A Component of the Puzzle, When Attempting to Understand Antipsychotics: A Theoretical Study of Chemical Reactivity Indexes

2018 ◽  
Vol 1 (1) ◽  
Keyword(s):  
Theoretical Study ◽  
Chemical Reactivity ◽  
Reactivity Indexes ◽  
Chemical Reactivity Indexes

scholarly journals Photosynthetic Pigments with Potential for a Photosynthetic Antenna: A DFT Analysis

2019 ◽  
Vol 2019 ◽  
pp. 1-17
Author(s):  
Jesús Francisco Monzón-Bensojo ◽  
Manuel A. Flores-Hidalgo ◽  
Diana Barraza-Jiménez
Keyword(s):  
Excited State ◽  
Electronic Properties ◽  
Photosynthetic Pigments ◽  
Density Functional ◽  
Higher Plants ◽  
Chemical Reactivity ◽  
Dielectric Constants ◽  
Electron Hole ◽  
Reactivity Indexes ◽  
Chemical Reactivity Indexes

Geometrical and electronic properties of the main photosynthetic pigments in higher plants such as chlorophylls and xanthophylls were studied to find potential candidates that were able to participate in an eventual zeolite-dye artificial antenna. CRDFT (chemical reactivity density functional theory) and TD-DFT (time-dependent DFT) methods were employed in ground-state and excited-state calculations, respectively. The evaluated electronic properties at the gas phase included (a) energies such as HOMO-LUMO band gap (H-L, ranging from 2.168 to 2.504 eV), adiabatic ionization potential (I, ranging from 5.964 to 7.207 eV), and adiabatic electronic affinity (A, ranging from 2.176 to 2.741 eV); (b) global chemical reactivity indexes such as electronegativity (χ, ranging from 4.121 to 4.974 eV), hardness (η, ranging from 1.812 to 2.233 eV), electrophilicity index (ω, ranging from 4.365 to 5.541 eV), and electroaccepting-electrodonating powers (ω+, ranging from 1.671 to 2.115 eV, and ω−, ranging from 4.375 to 5.273 eV); (c) electron-hole reorganization energies (λ, ranging from 0.225 to 0.519 eV and ranging from 0.168 to 0.425 eV, respectively) and electron-hole extraction potentials (EEP, ranging from 2.570 to 2.966 eV, and HEP, ranging from 5.538 to 7.012 eV, respectively); and (d) local chemical reactivity indexes like condensed Fukui functions (fk), condensed dual descriptor (f2r), and condensed local softness (sk). These electronic properties allowed the association between molecules and reactivity-selectivity criteria, under the context of charge transfer and electronic transitions. Also, the aforementioned electronic properties were determined for combinations made with the selected molecules (β-cryptoxanthin and zeaxanthin) and 5 solvents (n-hexane, diethyl ether, acetone, ethanol, and methanol) with upward dielectric constants (ε). From frequency calculations, IR spectra were obtained for combinations. Finally, excited-state computations were carried out to acquire UV-Vis spectra of the combinations. We conclude that the selection of dyes is controlled mainly by geometrical constraints rather than by electronic properties.

A theoretical study on the regioselectivity of 1,3-dipolar cycloadditions using DFT-based reactivity indexes

Tetrahedron ◽  
2004 ◽  
Vol 60 (50) ◽  
pp. 11503-11509 ◽  
Author(s):  
M.José Aurell ◽  
Luis R. Domingo ◽  
Patricia Pérez ◽  
Renato Contreras
Keyword(s):  
Theoretical Study ◽  
Dipolar Cycloadditions ◽  
Reactivity Indexes

Study of the Stability and Chemical Reactivity of a Series of Tetrazole Pyrimidine Hybrids by the Density Functional Theory Method (DFT)

2021 ◽  
Vol 37 (4) ◽  
pp. 805-812
Author(s):  
Ahissandonatien Ehouman ◽  
Adjoumanirodrigue Kouakou ◽  
Fatogoma Diarrassouba ◽  
Hakim Abdel Aziz Ouattara ◽  
Paulin Marius Niamien
Keyword(s):  
Density Functional ◽  
Theoretical Study ◽  
Molecular Descriptors ◽  
Chemical Reactivity ◽  
Density Functional Theory Method ◽  
Functional Theory ◽  
Reactivity Descriptors ◽  
The Density Functional Theory ◽  
The Stability ◽  
Global Reactivity Descriptors

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.

scholarly journals Theoretical Study of the Reaction of Formation of Some Free Phosphines by Stereoselective Hydrophosphination through DFT Method

2018 ◽  
pp. 1-10
Author(s):  
Kouadio Valery Bohoussou ◽  
Anoubilé Bénié ◽  
Mamadou Guy-Richard Koné ◽  
N’guessan Yao Silvère Diki ◽  
Kafoumba Bamba ◽  
...  
Keyword(s):  
Theoretical Study ◽  
Chemical Reactivity ◽  
Dft Method ◽  
Trans Form ◽  
Dft Methods ◽  
Activation Barriers ◽  
Reactivity Descriptors ◽  
Chemical Reactivity Descriptors ◽  
Theoretical Results ◽  
Cis Isomer

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.

Raman spectra of single walled carbon nanotubes at high temperatures: pretreating samples in a nitrogen atmosphere improves their thermal stability in air

2017 ◽  
Vol 19 (10) ◽  
pp. 7215-7227 ◽  
Author(s):  
J. Molina-Duarte ◽  
L. I. Espinosa-Vega ◽  
A. G. Rodríguez ◽  
R. A. Guirado-López
Keyword(s):  
Carbon Nanotubes ◽  
Thermal Stability ◽  
Raman Spectra ◽  
Temperature Interval ◽  
Theoretical Study ◽  
Chemical Reactivity ◽  
Single Walled Carbon Nanotubes ◽  
Nitrogen Atmosphere ◽  
Single Walled Carbon ◽  
Walled Carbon Nanotubes

We present a combined experimental and theoretical study dedicated to analyzing the structural stability and chemical reactivity of single walled carbon nanotubes (SWCNTs) in the presence of air and nitrogen atmospheres in the temperature interval of 300–1000 K.

Sign in / Sign up

Export Citation Format

Share Document