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.

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.

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.

Thermodynamic Stability of Hexagonal and Rhombohedral Bn at Cvd Conditions from Van der Waals Corrected First Principles Calculations

2019 ◽  
Author(s):  
Henrik Pedersen ◽  
Björn Alling ◽  
Hans Högberg ◽  
Annop Ektarawong
Keyword(s):  
Thin Films ◽  
Thermodynamic Stability ◽  
First Principles ◽  
Thermal Equilibrium ◽  
Density Functional ◽  
Van Der Waals ◽  
Chemical Vapor ◽  
First Principles Calculations ◽  
Functional Theory ◽  
The Stability

Thin films of boron nitride (BN), particularly the sp<sup>2</sup>-hybridized polytypes hexagonal BN (h-BN) and rhombohedral BN (r-BN) are interesting for several electronic applications given band gaps in the UV. They are typically deposited close to thermal equilibrium by chemical vapor deposition (CVD) at temperatures and pressures in the regions 1400-1800 K and 1000-10000 Pa, respectively. In this letter, we use van der Waals corrected density functional theory and thermodynamic stability calculations to determine the stability of r-BN and compare it to that of h-BN as well as to cubic BN and wurtzitic BN. We find that r-BN is the stable sp<sup>2</sup>-hybridized phase at CVD conditions, while h-BN is metastable. Thus, our calculations suggest that thin films of h-BN must be deposited far from thermal equilibrium.

Site preference and atomic ordering in the ternary Rh5Ga2As: first-principles calculations

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Nilanjan Roy ◽  
Sucharita Giri ◽  
Harshit ◽  
Partha P. Jana
Keyword(s):  
Total Energy ◽  
First Principles ◽  
Density Functional ◽  
Structure Type ◽  
Site Preference ◽  
X Ray Diffraction ◽  
Atomic Ordering ◽  
Functional Theory ◽  
The Stability ◽  
Bonding Characteristics

Abstract The site preference and atomic ordering of the ternary Rh5Ga2As have been investigated using first-principles density functional theory (DFT). An interesting atomic ordering of two neighboring elements Ga and As reported in the structure of Rh5Ga2As by X-ray diffraction data only is confirmed by first-principles total-energy calculations. The previously reported experimental model with Ga/As ordering is indeed the most stable in the structure of Rh5Ga2As. The calculation detected that there is an obvious trend concerning the influence of the heteroatomic Rh–Ga/As contacts on the calculated total energy. Interestingly, the orderly distribution of As and Ga that is found in the binary GaAs (Zinc-blende structure type), retained to ternary Rh5Ga2As. The density of states (DOS) and Crystal Orbital Hamiltonian Population (COHP) are calculated to enlighten the stability and bonding characteristics in the structure of Rh5Ga2As. The bonding analysis also confirms that Rh–Ga/As short contacts are the major driving force towards the overall stability of the compound.

scholarly journals Chalcogen Bond versus Weak Hydrogen Bond: Changing Contributions in Determining the Crystal Packing of [1,2,5]-Chalcogenadiazole-Fused Tetracyanonaphthoquinodimethanes

2021 ◽  
Vol 03 (02) ◽  
pp. 090-096
Author(s):  
Yusuke Ishigaki ◽  
Kota Asai ◽  
Takuya Shimajiri ◽  
Tomoyuki Akutagawa ◽  
Takanori Fukushima ◽  
...  
Keyword(s):  
Hydrogen Bond ◽  
Density Functional ◽  
Molecular Design ◽  
Crystal Packing ◽  
Cyano Group ◽  
Density Functional Theory Calculations ◽  
Weak Hydrogen Bond ◽  
Functional Theory ◽  
Chalcogen Bond ◽  
Thiadiazole Ring

The crystal structures of a series of tetracyanonaphthoquinodimethanes fused with a selenadiazole or thiadiazole ring revealed that their molecular packing is determined mainly by two intermolecular interactions: chalcogen bond (ChB) and weak hydrogen bond (WHB). ChB between Se and a cyano group dictates the packing of selenadiazole derivatives, whereas the S-based ChB is much weaker and competes with WHB in thiadiazole analogues. This difference can be explained by different electrostatic potentials as revealed by density functional theory calculations. A proper molecular design that weakens WHB can change the contribution of ChB in determining the crystal packing of thiadiazole derivatives.

Crystal structure of tamsulosin hydrochloride, C20H29N2O5SCl

2021 ◽  
pp. 1-7
Author(s):  
Nilan V. Patel ◽  
Joseph T. Golab ◽  
James A. Kaduk ◽  
Amy M. Gindhart ◽  
Thomas N. Blanton
Keyword(s):  
Crystal Structure ◽  
Hydrogen Bond ◽  
Hydrogen Atom ◽  
Powder Diffraction ◽  
Density Functional ◽  
Carbon Chain ◽  
Strong Hydrogen Bond ◽  
Powder Diffraction File ◽  
Ether Oxygen ◽  
Sulfonamide Group

The crystal structure of tamsulosin hydrochloride has been solved and refined using synchrotron X-ray powder diffraction data and optimized using density functional techniques. Tamsulosin hydrochloride crystallizes in space group P21 (#4) with a = 7.62988(2), b = 9.27652(2), c = 31.84996(12) Å, β = 93.2221(2)°, V = 2250.734(7) Å3, and Z = 4. In the crystal structure, two arene rings are connected by a carbon chain oriented roughly parallel to the c-axis. The crystal structure is characterized by two slabs of tamsulosin hydrochloride molecules perpendicular to the c-axis. As expected, each of the hydrogens on the protonated nitrogen atoms makes a strong hydrogen bond to one of the chloride anions. The result is to link the cations and anions into columns along the b-axis. One hydrogen atom of each sulfonamide group also makes a hydrogen bond to a chloride anion. The other hydrogen atom of each sulfonamide group forms bifurcated hydrogen bonds to two ether oxygen atoms. The powder pattern is included in the Powder Diffraction File™ as entry 00-065-1415.

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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