scholarly journals A Theoretical Study of Chemical Reactivity of Tartrazine Through DFT Reactivity Descriptors

2017 ◽  
Vol 58 (4) ◽  
Author(s):  
Luis Humberto Mendoza Huizar
Keyword(s):  
Free Radicals ◽  
Theoretical Study ◽  
Chemical Reactivity ◽  
Nucleophilic Attack ◽  
Initial Attack ◽  
Reactivity Descriptors ◽  
Pcm Model ◽  
Total Energies ◽  
Global And Local ◽  
Global Reactivity Descriptors

<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>

scholarly journals Analysis of chemical reactivity of aminocyclopyrachlor herbicide through the Fukui function

2015 ◽  
Vol 80 (6) ◽  
pp. 767-777 ◽  
Author(s):  
Luis Mendoza-Huizar
Keyword(s):  
Free Radical ◽  
Ionization Energy ◽  
Chemical Reactivity ◽  
Fukui Function ◽  
Similar Process ◽  
Neutral Form ◽  
Reactivity Descriptors ◽  
Total Energies ◽  
Global And Local ◽  
Global Reactivity Descriptors

We have calculated global and local DFT reactivity descriptors for aminocyclopyrachlor herbicide at the MP2/6-311++G (2d,2p) level of theory in the aqueous phase. Global reactivity descriptors such as ionization energy, molecular hardness, electrophilicity, and total energies were calculated to evaluate the aminocyclopyrachlor reactivity. Local reactivity was evaluated through the Fukui function. Our results suggest that the cationic and dipolar forms of aminocyclopyrachlor exhibit similar global reactivity and they are susceptible to deamination and decarboxylation. Also, the opening of the ring might become factible through free radical attacks to the neutral form, while a similar process is caused by nucleophilic attacks on the anionic form.

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.

A comparative theoretical study on the biological activity, chemical reactivity, and coordination ability of dichloro-substituted (1,3-thiazol-2-yl)acetamides

2014 ◽  
Vol 92 (3) ◽  
pp. 234-239 ◽  
Author(s):  
Ambrish Kumar Srivastava ◽  
Neeraj Misra
Keyword(s):  
Density Functional ◽  
Theoretical Study ◽  
Chemical Reactivity ◽  
Biological Activities ◽  
First Principle ◽  
Reactivity Descriptors ◽  
Natural Bonding Orbital ◽  
Coordination Ability ◽  
Global Reactivity Descriptors ◽  
Orbital Analysis

We present a theoretical study on three dichloro-substituted (1,3-thiazol-2-yl)acetamides using the first principle density functional approach. Natural bonding orbital analysis is used to discuss the coordination ability of molecules and various global reactivity descriptors are calculated to compare their chemical reactivity. Biological activities of all three molecules are also evaluated. We find that the present molecules show potential coordination ability and their chemical reactivity varies with the position of substitution. We also notice that all three molecules show remarkable biological activities and the (3,4)-dichloro-substituted molecule is relatively more active. The study suggests further investigations on these molecules for their pharmacological importance.

scholarly journals Chemical reactivity of quinclorac employing the HSAB local principle - Fukui function

2015 ◽  
Vol 13 (1) ◽  
Author(s):  
Luis H. Mendoza Huizar ◽  
Clara H. Rios-Reyes ◽  
Nubia J. Olvera-Maturano ◽  
Juvencio Robles ◽  
Jose A. Rodriguez
Keyword(s):  
Free Radical ◽  
Chemical Reactivity ◽  
Fukui Function ◽  
Nucleophilic Attack ◽  
Electrophilic Attack ◽  
Deprotonated Form ◽  
Reactivity Descriptors ◽  
Local Principle ◽  
Total Energies ◽  
Hydrogen Substitution

AbstractIn the present work we have calculated several DFT reactivity descriptors for quinclorac at the B3LYP/6- 311++G(2d,2p) and MP2/6-311++G(2d,2p) levels of theory in order to analyze its reactivity. Reactivity descriptors such as ionization energy, molecular hardness, electrophilicity, condensed Fukui function and total energies were determined to predict the reactivity of quinclorac. The influence of the solvent was taken into account employing the PCM model. The results indicate that the solvation modifies the values of quinclorac reactivity descriptors. The Fukui function values predict that an electrophilic attack on quinclorac might cause a dechlorination, while a nucleophilic attack might lead to a decarboxylation and a free radical attack would cause a hydrogen substitution on the quinoline ring. Quinclorac in deprotonated form would be susceptible to decarboxylation through an electrophilic attack while nucleophilic and free radical attacks would cause an attack on the hydrogens of the ring.

Atom Condensed Fukui Function for Condensed Phases and Biological Systems and Its Application to Enzymatic Fixation of Carbon Dioxide

2019 ◽  
Author(s):  
Javier Oller ◽  
David A. Sáez ◽  
Esteban Vöhringer-Martinez
Keyword(s):  
Carbon Dioxide ◽  
Aqueous Solution ◽  
Molecular System ◽  
Chemical Reactivity ◽  
Nucleophilic Attack ◽  
Stable Conformation ◽  
Fukui Functions ◽  
Reactivity Descriptors ◽  
Dynamics Simulations ◽  
Fixation Of Carbon Dioxide

<div><div><div><p>Local reactivity descriptors such as atom condensed Fukui functions are promising computational tools to study chemical reactivity at specific sites within a molecule. Their applications have been mainly focused on isolated molecules in their most stable conformation without considering the effects of the surroundings. Here, we propose to combine QM/MM Born-Oppenheimer molecular dynamics simulations to obtain the microstates (configurations) of a molecular system using different representations of the molecular environment and calculate Boltzmann weighted atom condensed local reac- tivity descriptors based on conceptual DFT. Our approach takes the conformational fluctuations of the molecular system and the polarization of its electron density by the environment into account allowing us to analyze the effect of changes in the molecular environment on reactivity. In this contribution, we apply the method mentioned above to the catalytic fixation of carbon dioxide by crotonyl-CoA carboxylase/reductase and study if the enzyme alters the reactivity of its substrate compared to an aqueous solution. Our main result is that the protein en- vironment activates the substrate by the elimination of solute-solvent hydrogen bonds from aqueous solution in the two elementary steps of the reaction mechanism: the nucleophilic attack of a hydride anion from NADPH on the α, β unsaturated thioester and the electrophilic attack of carbon dioxide on the formed enolate species.</p></div></div></div>

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.

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.

Global and Local Reactivity Descriptors Based on Quadratic and Linear Energy Models for α,β-Unsaturated Organic Compounds

2018 ◽  
Author(s):  
Javier Oller ◽  
Patricia Perez ◽  
Paul W. Ayers ◽  
Esteban Vöhringer-Martinez
Keyword(s):  
Carbon Dioxide ◽  
Density Functional ◽  
Chemical Reactivity ◽  
Fukui Function ◽  
Nucleophilic Attack ◽  
Quadratic Model ◽  
Molecular Response ◽  
Local Descriptors ◽  
Unsaturated Ketones ◽  
Global And Local

<div>Global and local descriptors of chemical reactivity can be derived from conceptual density functional theory. Their explicit form, however, depends on how the energy is defined as a function of the number of electrons. Within the existing interpolation models, here, the quadratic and the linear energy model were used to derive global descriptors as the electrophilicity and nucleophilicity (defined as the negative of the ionization potential) and local descriptors employing either the corresponding condensed fukui function in the linear model or the local response of the global descriptor in the quadratic model. The ability of these descriptors to predict the reactivity of molecules with more than one reactive site was first studied on a set of α ,β -unsaturated ketones, where experimental rate constants for the nucleophilic attack is known. With the validated descriptors the reactivity of α ,β -unsaturated carboxylic compounds with different heteroatoms as α ,β -unsaturated thioesters, esters and amides as alternative substrates for the enzymatic CO<sub>2</sub> fixation studied experimentally by Erb <i>et al.</i> was addressed. The carbon dioxide fixation involves the reduction of the neutral α ,β -unsaturated carboxylic compounds by a nucleophilic attack of a hydride anion from NADPH and the following electrophilic attack by carbon dioxide. It was found that condensed values of the linear fukui function within the fragment of molecular response approximation describe best the reactivity of α ,β -unsaturated ketones. For the two relevant processes involved in CO<sub>2</sub> fixation the amides present the largest reactivity in vacuum and in aqueous solution compared to the esters and thioesters and may, therefore, serve as alternative sustrates of carboxylases.</div>

Calculation of global and local reactivity descriptors of carbodiimides, a DFT study

2017 ◽  
Vol 16 (03) ◽  
pp. 1750019 ◽  
Author(s):  
Kathy Ramirez-Balderrama ◽  
Erasmo Orrantia-Borunda ◽  
Norma Flores-Holguin
Keyword(s):  
Electron Affinity ◽  
Density Functional ◽  
Chemical Reactivity ◽  
Basis Set ◽  
Chemical Hardness ◽  
Geometrical Parameters ◽  
Reactivity Descriptors ◽  
Local Reactivity ◽  
Global And Local ◽  
Local Reactivity Descriptors

Carbodiimides have been widely used for different purposes, such as an intermediary to form peptides bonds and esters, which have generated industrial, organic and biological applications. Diisoproylcarbodiimide (DIC), (3-(dimethylamino) propyl)ethylcarbodiimide (EDC) and N,N′-dicyclohexylcarbodiimide (DCC) are the most common carbodiimides, however, there exist other carbodiimides that are not normally used. Twelve carbodiimides including the above mentioned were chosen to study their chemical reactivity as well as their nucleophilic and electrophilic attack sites. Geometry optimization in gas and solution phases was obtained using Density Functional Theory (DFT) through B3LYP with 6-31G(d) and 6-311[Formula: see text]G(d,p) level. Global and local reactivity descriptors were calculated and analyzed such as chemical hardness, ionization potential, electron affinity, Fukui functions, dual descriptor and hypersoftness. The results obtained for geometrical parameters do not have significant differences for gas and solution phase. The introduction of diffuse functions has great impact in electron affinity, modifying notably the values of reactivity descriptors, but didn’t show qualitative differences, since the results found for both basis set calculations show that Cyanamide or CD1 is the most stable and CD11 present greater reactivity of all studied molecules. Also, the hypersoftness results obtained with 6-31G(d) are in agreement with the general affirmation that carbodiimides are easily attacked by nucleophiles and electrophiles in the central carbon–nitrogen double bond.

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