Study on Structure Properties of Pyridine Ionic Liquids of Different Acid-Based Chain Lengths

2011 ◽  
Vol 298 ◽  
pp. 51-55 ◽  
Author(s):  
Li Min Wang ◽  
De Qing Chu
Keyword(s):  
Density Functional Theory ◽  
Hydrogen Bond ◽  
Ionic Liquid ◽  
Ionic Liquids ◽  
Density Functional ◽  
Pyridine Ring ◽  
Functional Theory ◽  
Chain Lengths ◽  
Chlorine Ion ◽  
Structure Properties

By density functional theory (DFT) at B3LYP/6-311+G** levels, the pyridine ionic liquid with different substituent length has been studied. The calculated results show that the ionic liquid formed by pyridine and a chlorine ion has two main configurations (CCOOH-PyCl and CCOOHPyPCl). There are three combinative locations in each configuration of anion and cation. When the anion is located in the same location, as the acid length becomes longer, the hydrogen bond length between chlorine ion and hydrogen atom in pyridine ring becomes longer, the binding energy between chlorine ion and pyridine with different acid length becomes stronger.

Quantum Chemical Study on Structure Properties of Pyridine Ionic Liquids of Different Chain Lengths Substituent Group

2010 ◽  
Vol 113-116 ◽  
pp. 1968-1971
Author(s):  
Li Long ◽  
De Qing Chu ◽  
Li Min Wang
Keyword(s):  
Ionic Liquid ◽  
Density Functional ◽  
Quantum Chemical Study ◽  
Chemical Study ◽  
Functional Theory ◽  
Substituent Group ◽  
Chain Lengths ◽  
Chlorine Ion ◽  
Alkyl Length ◽  
Structure Properties

By using density functional theory (DFT) at B3LYP/6-31G* levels, the pyridine ionic liquid with different substituent length have been studied. The calculated results showed that the ionic liquid formed by pyridine and a chlorine ion has two main configurations (COH-PyCl and COH-PyPCl). There are three combinative locations in each configuration of anion and cation. When the anion is located in the same location, as the alkyl length becomes longer, the hydrogen bond length between chlorine ion and hydrogen atom in pyridine ring becomes longer, the binding energy between chlorine ion and pyridine with different alkyl length becomes weaker.

Density Functional Theory Study on the Absorption of CO2 by the Ionic Liquid of 1-butyl-3-methylimidazolium Acetate

2013 ◽  
Vol 807-809 ◽  
pp. 543-548 ◽  
Author(s):  
Yan Fei Chen ◽  
Yan Hong Cui ◽  
Dong Shun Deng ◽  
Ning Ai
Keyword(s):  
Density Functional Theory ◽  
Ionic Liquid ◽  
Ionic Liquids ◽  
Density Functional ◽  
Ion Pairs ◽  
Ion Pair ◽  
Frontier Molecular Orbitals ◽  
Density Functional Theory Study ◽  
Electronic Density ◽  
Functional Theory

The absorptions of CO2on the 1-butyl-3-methylimidazolium acetate ([Bmi [Ac]) with different substituents are calculated systematically at GGA/PW91 level. Three hydrogen bonds are formed between [A and cations of 1-n-[Bmi [A ([NBmi+) and 1-tert-[Bmi [A ([TBmi+). The interaction between CO2and the [NBmi [A by a C-O bond is much weaker than that with the [TBmi [A by forming a O...O...C...C four member-ring. The chemisorption of CO2on the ion pairs of [NBmi [A is much weaker than that on the [TBmi [A, resulted from the absorption energies analysis. The frontier molecular orbitals shows the electronic density overlap between absorbed CO2and the [A in CO2-[NBmi [A is much weaker than that in [TBmi [A. Therefore, the chemisorption of CO2on the ion pair of [NBmi [A is much weaker than that on the [TBmi [A. The ionic liquids based [NBmi+can be used repetitively, and the adsorbed CO2would be easier desorbed.

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.

Theory Study on Structure Property of N-Ethyl Morpholinium Ionic Liquid of Different Alkyl Length

2011 ◽  
Vol 301-303 ◽  
pp. 170-174 ◽  
Author(s):  
Li Min Wang ◽  
Chuan Xia
Keyword(s):  
Hydrogen Bond ◽  
Ionic Liquid ◽  
Hydrogen Atom ◽  
Density Functional ◽  
Green Solvent ◽  
Structure Property ◽  
Functional Theory ◽  
The Stability ◽  
Chlorine Ion ◽  
Alkyl Length

The ionic liquid is a green solvent and catalyst, its application is abroad. By using at density functional theory (DFT) at B3LYP/6-31G* levels, The N-ethyl morpholinium ionic liquid with different alkyl length have been studied. The computed results indicate that the ionic liquid formed by ethyl N-ethyl morpholinium and a chlorine ion has nine structures and eighteen positions. Three hydrogen bonds have been formed in each position, the hydrogen bond between chlorine ion and hydrogen atom in morpholinium ring is strongest and shortest. The hydrogen bond between chlorine ion and hydrogen atom in ethyl is weaker, which can strengthen the stability of ion pair. The nine structures of the ionic liquid formed by ethyl N-ethyl morpholinium and a chlorine ion are compared, the ionic liquid of MO1,2NC和MO1,2LC is more stable, the energy released of MO1,2LC is biggest, the energy released of MO1,2NB is smallest. For ethyl N-ethyl morpholinium, propyl N-ethyl morpholinium and butyl N-ethyl morpholinium, as the alkyl length becomes longer, the binding energy between chlorine ion and morpholinium with different alkyl length becomes weaker.

scholarly journals Thermal Stability and Decomposition Kinetics of 1-Alkyl-2,3-Dimethylimidazolium Nitrate Ionic Liquids: TGA and DFT Study

Materials ◽  
2021 ◽  
Vol 14 (10) ◽  
pp. 2560
Author(s):  
Jianwen Meng ◽  
Yong Pan ◽  
Fan Yang ◽  
Yanjun Wang ◽  
Zhongyu Zheng ◽  
...  
Keyword(s):  
Thermal Stability ◽  
Density Functional Theory ◽  
Ionic Liquids ◽  
Density Functional ◽  
Density Functional Theory Calculations ◽  
Nitrogen Atmosphere ◽  
Decomposition Kinetics ◽  
Heating Rates ◽  
Functional Theory ◽  
Kinetics Of

The thermal stability and decomposition kinetics analysis of 1-alkyl-2,3-dimethylimidazole nitrate ionic liquids with different alkyl chains (ethyl, butyl, hexyl, octyl and decyl) were investigated by using isothermal and nonisothermal thermogravimetric analysis combined with thermoanalytical kinetics calculations (Kissinger, Friedman and Flynn-Wall-Ozawa) and density functional theory (DFT) calculations. Isothermal experiments were performed in a nitrogen atmosphere at 240, 250, 260 and 270 °C. In addition, the nonisothermal experiments were carried out in nitrogen and air atmospheres from 30 to 600 °C with heating rates of 5, 10, 15, 20 and 25 °C/min. The results of two heating modes, three activation energy calculations and density functional theory calculations consistently showed that the thermal stability of 1-alkyl-2,3-dimethylimidazolium nitrate ionic liquids decreases with the increasing length of the alkyl chain of the substituent on the cation, and then the thermal hazard increases. This study could provide some guidance for the safety design and use of imidazolium nitrate ionic liquids for engineering.

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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