scholarly journals Chemical Reactivity of Isoproturon, Diuron, Linuron, and Chlorotoluron Herbicides in Aqueous Phase: A Theoretical Quantum Study Employing Global and Local Reactivity Descriptors

2015 ◽  
Vol 2015 ◽  
pp. 1-9 ◽  
Author(s):  
Luis Humberto Mendoza-Huizar
Keyword(s):  
Free Radical ◽  
Aqueous Phase ◽  
Chemical Reactivity ◽  
The Other ◽  
Reactivity Descriptors ◽  
Local Reactivity ◽  
Other Hand ◽  
Aqueous Conditions ◽  
Global And Local ◽  
Local Reactivity Descriptors

We have calculated global and local DFT reactivity descriptors for isoproturon, diuron, linuron, and chlorotoluron herbicides at the MP2/6-311++G(2d,2p) level of theory. The results suggest that, in aqueous conditions, chlorotoluron, linuron, and diuron herbicides may be degraded by elimination of urea moiety through electrophilic attacks. On the other hand, electrophilic, nucleophilic, and free radical attacks on isoproturon may cause the elimination of isopropyl fragment.

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.

scholarly journals A DFT study of the chemical reactivity of thiobencarb and its oxidized derivatives in aqueous phase

2018 ◽  
Vol 83 (9) ◽  
pp. 981-993
Author(s):  
Luis Mendoza-Huizar
Keyword(s):  
Free Radical ◽  
Aromatic Ring ◽  
Aqueous Phase ◽  
Chemical Reactivity ◽  
Dft Study ◽  
Fukui Functions ◽  
Local Reactivity ◽  
Reactive Zone ◽  
Global And Local ◽  
Condensed Fukui Functions

In the present work, the global and local reactivity of S-(4-chlorobenzyl)- N,N-diethylthiocarbamate (TB) and its oxidized derivatives (sulfone (TBSu) and sulfoxide (TBS) were analyzed. In addition, the chemical reactivities of the dechlorinated forms of TB (DTB), TBSu (DTBSu) and TBS (DTBS) were studied. The calculations were performed at the wB97XD/6- -311++G(2d,2p) level of theory in the aqueous phase. The condensed Fukui functions indicated that for TB and DTB, the most preferred sites for donating electron in a reaction are located on the S and N atoms, while the most reactive sites for accepting electrons are associated with the aromatic ring (AR). For TBS and DTBS, the more reactive sites are located on AR, S and AR for nucleophilic, electrophilic and free radical attacks, respectively. In the case of TBSu and DTBSu, the results showed AR to be the more reactive zone for the three kinds of attacks. These last results suggest that cleavage of the C?S bond in TB, TBS and their dechlorinated forms is favored by electrophilic attacks. Additionally, the obtained results suggest that in TB, it is plausible that the cleavage of the C?N is favored on attack of this molecule by electrophiles.

scholarly journals A DFT study of the chemical reactivity of cimetidine A, C and D in the gas, H2O, MeOH and EtOH solvents

2017 ◽  
Vol 82 (1) ◽  
pp. 25-37
Author(s):  
Huizar Mendoza ◽  
Guillermo Salgado-Morán ◽  
Wilson Cardona-Villada ◽  
Alison Pacheco ◽  
Daniel Glossman-Mitnik
Keyword(s):  
Free Radical ◽  
Gas Phase ◽  
Aqueous Phase ◽  
Chemical Reactivity ◽  
Fukui Function ◽  
Dft Study ◽  
Reactivity Descriptors ◽  
Global And Local

% Fukui % DFT s KR nema In the present work, we have analyzed the chemical reactivity of cimetidine A, C and D in different solvents; through the evaluation of global and local DFT reactivity descriptors. In the gas, MeOH and EtOH phases, cimetidine A, C and D exhibit energy differences of 3-11 kcal mol-1. But, in the aqueous phase, cimetidine A and D are approximately isoenergetic. The values of the hardness indicate that cimetidine A, C and D are more reactive in the presence of a solvent than in the gas phase. Also, our results suggest that CimC and CimD are better nucleophiles that CimA. The Fukui Function values suggest that the more reactive sites of CimA are not modified in the different solvents. In the case of CimC, the more reactive sites to electrophilic and free radical attacks are located on the thioether sulfur. For CimD, the number and place of the electrophilic and free radical sites are independent of the solvent.

scholarly journals Theoretical investigation of the molecular structure and molecular docking of naratriptan

2020 ◽  
Vol 85 (10) ◽  
pp. 1291-1301
Author(s):  
Wendolyne López-Orozco ◽  
Reyes Rios ◽  
Huizar Mendoza
Keyword(s):  
Molecular Structure ◽  
Molecular Docking ◽  
Aqueous Phase ◽  
Chemical Study ◽  
Docking Studies ◽  
Reactivity Descriptors ◽  
Chemical Behaviour ◽  
Global And Local ◽  
5Ht1b Receptor ◽  
Local Reactivity Descriptors

In this work, a computational chemical study of the naratriptan was carried out at the X/DGDZVP (where X = B3LYP, M06, M06L and ?B97XD) level of theory, the results suggest the existence of two possible conformers in the aqueous phase. The evaluation of the global and local reactivity descriptors indicates that both conformers show the same chemical behaviour. The docking studies reveal that both conformers bind to TYR359 residue of the 5HT1B receptor. Also, the first conformer binds to the receptor through THR209 and THR213 while the second one through THR209 and SER 212.

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.

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