INVESTIGATION OF THE INTERACTION OF HYDROXYL AND HYDROPEROXYL RADICALS WITH ETHENE IN THE PRESENCE OF WATER MOLECULES USING COMPUTATIONAL METHODS

2007 ◽  
Vol 06 (02) ◽  
pp. 377-397
Author(s):  
SEIFOLLAH JALILI ◽  
MINA SOLEIMANI
Keyword(s):  
Density Functional Theory ◽  
Hydrogen Bond ◽  
Computational Methods ◽  
Density Functional ◽  
Atoms In Molecules ◽  
Water Molecules ◽  
Functional Theory ◽  
Aim Theory ◽  
Thermodynamical Parameters ◽  
The Stability

In this work, the interaction of hydroxyl and hydroperoxyl radicals with ethene in the presence of water molecules and the stability of C 2 H 4 + HO x + ( H 2 O )y; x = 1–2, y = 0–5 clusters were investigated using computational methods. Also, hydrogen bond of these clusters was investigated using Density Functional Theory (DFT) and Atoms in Molecules (AIM) theory. Thermodynamical parameters for the interaction of hydroxyl and hydroperoxyl radicals with ethene in the presence of water molecules were also calculated. We report new results for the interaction of hydroxyl and hydroperoxyl radicals with ethene in the presence of water molecules.

Density Functional Computations on 6-Aminouracil: Effect of Amino Group in the 6th Position on the Watson–Crick Base Pair Uridine–Adenosine

2016 ◽  
Vol 69 (8) ◽  
pp. 881 ◽  
Author(s):  
M. Alcolea Palafox ◽  
V. K. Rastogi
Keyword(s):  
Density Functional Theory ◽  
Density Functional ◽  
Water Molecules ◽  
Amino Group ◽  
Infrared And Raman Spectra ◽  
Interaction Energies ◽  
Base Pairs ◽  
Functional Theory ◽  
The Stability ◽  
Density Functional Computations

The predicted infrared and Raman spectra of 6-aminouracil in the solid state by density functional theory methods were analyzed and compared with the experimental spectra. The effect of amino substitution in the sixth position of uridine on the stability of the Watson–Crick (WC) base pairs with deoxyadenosine was evaluated. Different WC pairs of 5-aminouridine, 6-aminouridine, and uridine with deoxyadenosine were simulated, and the counterpoise-corrected interaction energies were determined. 6-Aminouridine produces a stronger WC pair than that involving uridine, and its high dipole moment facilitates interaction with water molecules.

scholarly journals Computational Evaluation of Intermolecular Interaction in Poly(Styrene-Maleic Acid)-Water Complexes Using Density Functional Theory

2021 ◽  
Vol 21 (6) ◽  
pp. 1537
Author(s):  
Daru Seto Bagus Anugrah ◽  
Laura Virdy Darmalim ◽  
Permono Adi Putro ◽  
Liana Dewi Nuratikah ◽  
Nurwarrohman Andre Sasongko ◽  
...  
Keyword(s):  
Density Functional Theory ◽  
Hydrogen Bond ◽  
Hydrogen Bonding ◽  
Molecular Orbital ◽  
Maleic Acid ◽  
Density Functional ◽  
Basis Set ◽  
Water Molecules ◽  
Functional Theory ◽  
High Hydrogen

The high application of Poly(styrene-maleic acid) (PSMA) in an aqueous environment, such as biomedical purposes, makes the interaction between PSMA and water molecules interesting to be investigated. This study evaluated the conformation, the hydrogen bond network, and the stabilities of all the possible intermolecular interactions between PSMA with water (PSMA−(H2O)n, n = 1–5). All calculations were executed using the density functional theory (DFT) method at B3LYP functional and the 6–311G** basis set. The energy interaction of PSMA–(H2O)5 complex was –56.66 kcal/mol, which is classified as high hydrogen bond interaction. The Highest Occupied Molecular Orbital (HOMO) – Lowest Unoccupied Molecular Orbital (LUMO) energy gap decreased with the rise in the number of H2O molecules, representing a more reactive complex. The strongest hydrogen bonding in PSMA–(H2O)5 wasformed through the interaction on O72···O17–H49 with stabilizing energy of 50.32 kcal/mol, that analyzed by natural bond orbital (NBO) theory. The quantum theory atoms in molecules (QTAIM) analysis showed that the hydrogen bonding (EHB) value on O72···O17–H49 was –14.95 kcal/mol. All computational data revealed that PSMA had moderate to high interaction with water molecules that indicated the water molecules were easily transported and kept in the PSMA matrix.

A Density Functional Theory Study on the Water Aggregation Behaviour of Fatty-Acid Based Anionic Surface Active Ionic Liquids

2021 ◽  
Author(s):  
Suresh Sampathkumar ◽  
Subramaniam Vijayakumar
Keyword(s):  
Density Functional Theory ◽  
Hydrogen Bond ◽  
Ionic Liquids ◽  
Fatty Acid ◽  
Water Cluster ◽  
Density Functional ◽  
Water Molecules ◽  
Hydrogen Bond Interaction ◽  
Functional Theory ◽  
Aggregation Behaviour

Abstract The hydrogen bond interactions between methyl-imidazolium cation (MIM+) and fatty-acid anions (CmHnCOO–, where m=1–6; n-3–13) of ionic liquids are studied in both gas phase and water phase using density functional theory. The structural properties show that the presence of N–H···O and C–H···O hydrogen bonds between [MIM]+ and [CmHnCOO]– (m=1–6;n-3–13) ionic liquids. From the vibrational frequency analysis it was found that the hydrogen bond interaction between [MIM]+ and [CmHnCOO]– (m=1–6;n-3–13) ionic liquids are red-shifted in frequency. The natural bond orbital analysis show that the N–H···O hydrogen bond associated with the large charge transfer which has the higher stabilization energy (i.e. E(2) ~ 38 kcal/mol). Further, the cation/anion–water cluster (H2O)1-3 interactions show that the water molecules are preferred to interact with anions. In the case of ionic liquids–water cluster interaction, the water molecules occupies the interstitial space between cation and anion of ionic liquids which results in weakening the cation-anion interaction.

scholarly journals The stability and electronic and photocatalytic properties of the ZnWO4 (010) surface determined from first-principles and thermodynamic calculations

RSC Advances ◽  
2021 ◽  
Vol 11 (38) ◽  
pp. 23477-23490
Author(s):  
Yonggang Wu ◽  
Jihua Zhang ◽  
Bingwei Long ◽  
Hong Zhang
Keyword(s):  
Phase Diagram ◽  
Density Functional Theory ◽  
First Principles ◽  
Density Functional ◽  
Thermodynamic Calculations ◽  
Photocatalytic Properties ◽  
Thermodynamic Approach ◽  
Functional Theory ◽  
Stability Phase Diagram ◽  
The Stability

The ZnWO4 (010) surface termination stability is studied using a density functional theory-based thermodynamic approach. The stability phase diagram shows that O-Zn, DL-W, and DL-Zn terminations of ZnWO4 (010) can be stabilized.

scholarly journals Study on the interaction between catechin and cholesterol by the density functional theory

2020 ◽  
Vol 18 (1) ◽  
pp. 357-368
Author(s):  
Kaiwen Zheng ◽  
Kai Guo ◽  
Jing Xu ◽  
Wei Liu ◽  
Junlang Chen ◽  
...  
Keyword(s):  
Density Functional Theory ◽  
Hydrogen Bond ◽  
Charge Transfer ◽  
Density Functional ◽  
Antioxidant Properties ◽  
Micelle Formation ◽  
Aromatic Rings ◽  
Hydrogen Bond Interaction ◽  
Functional Theory ◽  
The Density Functional Theory

AbstractCatechin – a natural polyphenol substance – has excellent antioxidant properties for the treatment of diseases, especially for cholesterol lowering. Catechin can reduce cholesterol content in micelles by forming insoluble precipitation with cholesterol, thereby reducing the absorption of cholesterol in the intestine. In this study, to better understand the molecular mechanism of catechin and cholesterol, we studied the interaction between typical catechins and cholesterol by the density functional theory. Results show that the adsorption energies between the four catechins and cholesterol are obviously stronger than that of cholesterol themselves, indicating that catechin has an advantage in reducing cholesterol micelle formation. Moreover, it is found that the molecular interactions of the complexes are mainly due to charge transfer of the aromatic rings of the catechins as well as the hydrogen bond interactions. Unlike the intuitive understanding of a complex formed by hydrogen bond interaction, which is positively correlated with the number of hydrogen bonds, the most stable complexes (epicatechin–cholesterol or epigallocatechin–cholesterol) have only one but stronger hydrogen bond, due to charge transfer of the aromatic rings of catechins.

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