scholarly journals New Insights to Understand the CoMFA Analysis within the Density Functional Theory Framework

2021 ◽  
Vol 2 (11) ◽  
pp. 1067-1073
Author(s):  
Roya Momen ◽  
Alejandro Morales-Bayuelo
Keyword(s):  
Density Functional Theory ◽  
Density Functional ◽  
Chemical Reactivity ◽  
3D Qsar ◽  
Quantum Similarity ◽  
Functional Theory ◽  
Reactivity Descriptors ◽  
The Density Functional Theory ◽  
Wide Range ◽  
Theory Framework

The Three-Dimensional Quantitative Structure-Activity Relationship (3D QSAR) models now have a wide range of applications; however, new methodologies are required due to the complexity in understanding their results. This research presents a generalized version of quantum similarity field and chemical reactivity descriptors within the density functional theory framework. By taking reference compounds, this generalized methodology can be used to understand the biological activity of a molecular set. In this sense, this methodology allows to study of the CoMFA in quantum similarity and chemical reactivity. It is feasible to investigate steric and electrostatic effects on local substitutions using this method. They were considering that how these methodologies could be used when the receptor is known or unknown.

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 Calculation of the Global and Local Conceptual DFT Indices for the Prediction of the Chemical Reactivity Properties of Papuamides A–F Marine Drugs

Molecules ◽  
2019 ◽  
Vol 24 (18) ◽  
pp. 3312 ◽  
Author(s):  
Norma Flores-Holguín ◽  
Juan Frau ◽  
Daniel Glossman-Mitnik
Keyword(s):  
Density Functional Theory ◽  
Active Sites ◽  
Density Functional ◽  
Chemical Reactivity ◽  
Active Regions ◽  
Conceptual Density Functional Theory ◽  
Functional Theory ◽  
Reactivity Descriptors ◽  
Global And Local

A well-behaved model chemistry previously validated for the study of the chemical reactivity of peptides was considered for the calculation of the molecular properties and structures of the Papuamide family of marine peptides. A methodology based on Conceptual Density Functional Theory (CDFT) was chosen for the determination of the reactivity descriptors. The molecular active sites were associated with the active regions of the molecules related to the nucleophilic and electrophilic Parr functions. Finally, the drug-likenesses and the bioactivity scores for the Papuamide peptides were predicted through a homology methodology relating them with the calculated reactivity descriptors, while other properties such as the pKas were determined following a methodology developed by our group.

scholarly journals Synthesis, Characterization, Catalytic Activity, and DFT Calculations of Zn(II) Hydrazone Complexes

Molecules ◽  
2020 ◽  
Vol 25 (18) ◽  
pp. 4043 ◽  
Author(s):  
Temiloluwa T. Adejumo ◽  
Nikolaos V. Tzouras ◽  
Leandros P. Zorba ◽  
Dušanka Radanović ◽  
Andrej Pevec ◽  
...  
Keyword(s):  
Density Functional Theory ◽  
Gas Phase ◽  
Molecular Orbital ◽  
Density Functional ◽  
Chemical Potential ◽  
Chemical Reactivity ◽  
Geometry Optimization ◽  
Coupling Reaction ◽  
Functional Theory ◽  
Reactivity Descriptors

Two new Zn(II) complexes with tridentate hydrazone-based ligands (condensation products of 2-acetylthiazole) were synthesized and characterized by infrared (IR) and nuclear magnetic resonance (NMR) spectroscopy and single crystal X-ray diffraction methods. The complexes 1, 2 and recently synthesized [ZnL3(NCS)2] (L3 = (E)-N,N,N-trimethyl-2-oxo-2-(2-(1-(pyridin-2-yl)ethylidene)hydrazinyl)ethan-1-aminium) complex 3 were tested as potential catalysts for the ketone-amine-alkyne (KA2) coupling reaction. The gas-phase geometry optimization of newly synthesized and characterized Zn(II) complexes has been computed at the density functional theory (DFT)/B3LYP/6–31G level of theory, while the highest occupied molecular orbital and lowest unoccupied molecular orbital (HOMO and LUMO) energies were calculated within the time-dependent density functional theory (TD-DFT) at B3LYP/6-31G and B3LYP/6-311G(d,p) levels of theory. From the energies of frontier molecular orbitals (HOMO–LUMO), the reactivity descriptors, such as chemical potential (μ), hardness (η), softness (S), electronegativity (χ) and electrophilicity index (ω) have been calculated. The energetic behavior of the investigated compounds (1 and 2) has been examined in gas phase and solvent media using the polarizable continuum model. For comparison reasons, the same calculations have been performed for recently synthesized [ZnL3(NCS)2] complex 3. DFT results show that compound 1 has the smaller frontier orbital gap so, it is more polarizable and is associated with a higher chemical reactivity, low kinetic stability and is termed as soft molecule.

scholarly journals Polyelectrolyte chain at thermal equilibrium: A comparison between the density functional theory framework (DFT) and the molecular dynamic simulations (MD)

2021 ◽  
Author(s):  
Mike J. Edwards
Keyword(s):  
Density Functional Theory ◽  
Molecular Dynamic ◽  
Thermal Equilibrium ◽  
Density Functional ◽  
Molecular Dynamic Simulations ◽  
Dynamic Simulations ◽  
Functional Theory ◽  
The Density Functional Theory ◽  
Bjerrum Length ◽  
Theory Framework

ABSTRACTBy means of the density functional theory framework (DFT) as well as the molecular dynamic simulations (MD), a polyelectrolyte chain (PE) in the good solvent conditions at thermal equilibrium is studied. The strength of the electrostatic interactions is varied by the Bjerrum length of the solvent. It turns out that average extension of a PE scales with the degree of polymerization, very much similar to a neutral polymer chain in good solvent. Remarkably, the difference between a PE and a neutral chain appears to be solely in the correlations among monomers which are stored in the Virial coefficients. Interestingly, upon increasing the Bjerrum length of solvent, the chain shrinks. This outcome is confirmed by the DFT framework as well as the MD simulations.SIGNIFICANCEThe significance of this study is that it strongly criticizes the idea (already mentioned in T. Kreer, Soft Matter, 12, 3479 (2016)) that the PEs behave similar to a neutral ideal chain. This study could be useful in our understanding of biopolymers.

Theoretical study ofFeB35+nN36-n(n = 0, 1) nanocages: Chemical reactivity descriptors

2015 ◽  
Vol 14 (04) ◽  
pp. 1550026 ◽  
Author(s):  
Davood Farmanzadeh ◽  
Hamid Rezainejad
Keyword(s):  
Density Functional ◽  
Chemical Reactivity ◽  
Chemical Species ◽  
Dft Method ◽  
High Reactivity ◽  
Binding Energies ◽  
Functional Theory ◽  
Reactivity Descriptors ◽  
The Density Functional Theory ◽  
Chemical Reactivity Descriptors

In this study, by the density functional theory (DFT) method-based reactivity descriptors, the electronic properties and chemical reactivity of Fe substituted nanocage, FeB35+nN36-n(n = 0, 1), were investigated in gaseous and aqueous phases. The calculated binding energies of Fe atoms revealed that the substituting Fe atom in some locations of nanocage make the system more stable. The calculated global descriptors showed that the substituted Fe remarkably increases the chemical reactivity of B36N36. Also, local descriptors showed that the high reactivity of substituted nanocages is mainly related to Fe atom and these chemical species are more talented for nucleophilic attacks. The results of this work may be useful to investigate the effects of substituted metals in chemical reactivity of BN nanostructures.

Sign in / Sign up

Export Citation Format

Share Document