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.

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.

scholarly journals Quantum-chemical study of stable, meta-stable and high-pressure alumina polymorphs and aluminum hydroxides

2014 ◽  
Vol 2 (32) ◽  
pp. 13143-13158 ◽  
Author(s):  
Michael F. Peintinger ◽  
Michael J. Kratz ◽  
Thomas Bredow
Keyword(s):  
High Pressure ◽  
Quantum Chemical ◽  
Density Functional ◽  
Quantum Chemical Study ◽  
Chemical Study ◽  
Functional Theory ◽  
Aluminum Hydroxides ◽  
Hybrid Density Functional ◽  
Alumina Polymorphs ◽  
Structure Properties

The structure, properties and stability of 7 thermodynamically stable, meta-stable and high-pressure Al2O3 polymorphs and the structure and relative stability of 4 Al hydroxides were calculated with periodic hybrid density functional theory and compared with available experimental data.

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 Quantum Chemical Study of Mixed-Ligand Monometallic Ruthenium(II) Complex of Composition [(bpy)2Ru(H3Imbzim)](ClO4)2·2H2O

2014 ◽  
Vol 2014 ◽  
pp. 1-8
Author(s):  
Mohsin Yousuf Lone ◽  
Prakash Chandra Jha
Keyword(s):  
Absorption Spectra ◽  
Density Functional ◽  
Quantum Chemical Study ◽  
Chemical Study ◽  
Mixed Ligand ◽  
Excitation Energies ◽  
Functional Theory ◽  
Effect Of Solvent ◽  
The Density Functional Theory ◽  
Metal Ligand

On the basis of density functional theoretical approach, we have assessed the ground state geometries and absorption spectra of recently synthesized monometallic ruthenium (II) complex of composition [(bpy)2Ru(H3Imbzim)](ClO4)2·2H2O where bpy = 2,2′-bypyridine and H3Imbzim = 4,5-bis(benzimidazol-2-yl)imidazole. The all different kinds of charge transfers such as ligand-ligand, and metal-ligand have been quantified, compared, and contrasted with the experimental results. In addition, the effect of solvent on excitation energies has been evaluated. In spite of some digital discrepancies in calculated and observed geometries, as well as in absorption spectra, the density functional theory (DFT) seems to explain the main features of this complex.

scholarly journals Structural, Electronic, and Vibrational Properties of Isoniazid and Its Derivative N-Cyclopentylidenepyridine-4-carbohydrazide: A Quantum Chemical Study

2014 ◽  
Vol 2014 ◽  
pp. 1-15 ◽  
Author(s):  
Anoop kumar Pandey ◽  
Abhishek Bajpai ◽  
Vikas Baboo ◽  
Apoorva Dwivedi
Keyword(s):  
Density Functional ◽  
Quantum Chemical Study ◽  
Chemical Study ◽  
Basis Sets ◽  
Ground State Structure ◽  
Vibrational Modes ◽  
Functional Theory ◽  
Complete Assignment ◽  
Experimental Values ◽  
Homo Lumo

Isoniazid (Laniazid, Nydrazid), also known as isonicotinylhydrazine (INH), is an organic compound that is the first-line medication in prevention and treatment of tuberculosis. The optimized geometry of the isoniazid and its derivative N-cyclopentylidenepyridine-4-carbohydrazide molecule has been determined by the method of density functional theory (DFT). For both geometry and total energy, it has been combined with B3LYP functionals having LANL2DZ and 6-311 G (d, p) as the basis sets. Using this optimized structure, we have calculated the infrared wavenumbers and compared them with the experimental data. The calculated wavenumbers by LANL2DZ are in an excellent agreement with the experimental values. On the basis of fully optimized ground-state structure, TDDFT//B3LYP/LANL2DZ calculations have been used to determine the low-lying excited states of isoniazid and its derivative. Based on these results, we have discussed the correlation between the vibrational modes and the crystalline structure of isoniazid and its derivative. A complete assignment is provided for the observed FTIR spectra. The molecular HOMO, LUMO composition, their respective energy gaps, and MESP contours/surfaces have also been drawn to explain the activity of isoniazid and its derivative.

Effective corrosion inhibition of mild steel in acidic medium using inexpensive kermes natural dye: experimental and quantum chemical study

2018 ◽  
Vol 65 (6) ◽  
pp. 626-636 ◽  
Author(s):  
Nobl F. El Boraei ◽  
Shimaa Abdel Halim ◽  
Magdy A.M. Ibrahim
Keyword(s):  
Mild Steel ◽  
Corrosion Inhibition ◽  
Density Functional ◽  
Steel Surface ◽  
Quantum Chemical Study ◽  
Chemical Study ◽  
Functional Theory ◽  
Content Type ◽  
Visible Spectra ◽  
Corrosion Of Steel

PurposeThe purpose of this paper is to test the Natural Kermes dye (NKD) as a cheap and stable corrosion inhibitor for mild steel in 1.0 M HCl and its adsorption mechanism on the steel surface.Design/methodology/approachThe inhibition action of NKD was studied using AC impedance, potentiodynamic polarization, scanning electron microscope (SEM) and UV-visible spectra techniques complemented with quantum study.FindingsHere, the authors show that addition of NKD inhibits effectively the corrosion of steel in HCl solution via its adsorption on the steel surface. The inhibition efficiency of NKD increases with increase in its concentration and decreases with temperature. Potentiodynamic results revealed that NKD acts as a mixed–type inhibitor. Thermodynamic parameters for corrosion and adsorption process were obtained from the experimental data. Moreover, the experimental inhibition efficiencies were correlated with the electronic properties of NKD using density functional theory.Originality/valueTo the best of the authors’ knowledge, this is the first report showing the effect of NKD on the corrosion inhibition of steel.

Quantum-chemical study of nitrogen and magnesium co-doping in α-Cr2O3

2016 ◽  
Vol 30 (14) ◽  
pp. 1650219
Author(s):  
Soraya Jácome ◽  
Arvids Stashans
Keyword(s):  
First Principles ◽  
Density Functional ◽  
Quantum Chemical Study ◽  
Chemical Study ◽  
First Principles Calculations ◽  
Generalized Gradient ◽  
Functional Theory ◽  
Text Type ◽  
Co Doping ◽  
The Density Functional Theory

Study of corundum-type chromium oxide ([Formula: see text]-Cr2O3) crystal doped with the nitrogen and magnesium impurities has been carried out through the use of first-principles calculations based on the density functional theory (DFT) and generalized gradient approximation (GGA). Three cases corresponding different impurity–impurity distances have been considered. Structural, electronic and magnetic properties have been studied for all co-doping cases. The [Formula: see text]-type electrical conductivity was found when distance between the Mg and N atoms is equal to 4.10 Å. The results obtained are consistent with the available experimental data.

scholarly journals Photo-Induced Charge Separation vs. Degradation of a BODIPY-Based Photosensitizer Assessed by TDDFT and RASPT2

Catalysts ◽  
2018 ◽  
Vol 8 (11) ◽  
pp. 520 ◽  
Author(s):  
Karl Ziems ◽  
Stefanie Gräfe ◽  
Stephan Kupfer
Keyword(s):  
Density Functional ◽  
Parent Compound ◽  
Quantum Chemical Study ◽  
Chemical Study ◽  
Catalytic Performance ◽  
Triplet States ◽  
Spin Orbit Coupling ◽  
Functional Theory ◽  
Component Approach ◽  
Turn Over

A meso-mesityl-2,6-iodine substituted boron dipyrromethene (BODIPY) dye is investigated using a suite of computational methods addressing its functionality as photosensitizer, i.e., in the scope of light-driven hydrogen evolution in a two-component approach. Earlier reports on the performance of the present iodinated BODIPY dye proposed a significantly improved catalytic turn-over compared to its unsubstituted parent compound based on the population of long-lived charge-separated triplet states, accessible due to an enhanced spin-orbit coupling (SOC) introduced by the iodine atoms. The present quantum chemical study aims at elucidating the mechanisms of both the higher catalytic performance and the degradation pathways. Time-dependent density functional theory (TDDFT) and multi-state restricted active space perturbation theory through second-order (MS-RASPT2) simulations allowed identifying excited-state channels correlated to iodine dissociation. No evidence for an improved catalytic activity via enhanced SOCs among the low-lying states could be determined. However, the computational analysis reveals that the activation of the dye proceeds via pathways of the (prior chemically) singly-reduced species, featuring a pronounced stabilization of charge-separated species, while low barriers for carbon-iodine bond breaking determine the photostability of the BODIPY dye.

scholarly journals Quantum Chemical Study Aimed at Modeling Efficient Aza-BODIPY NIR Dyes: Molecular and Electronic Structure, Absorption, and Emission Spectra

Molecules ◽  
2020 ◽  
Vol 25 (22) ◽  
pp. 5361
Author(s):  
Alexander E. Pogonin ◽  
Artyom Y. Shagurin ◽  
Maria A. Savenkova ◽  
Felix Yu. Telegin ◽  
Yuriy S. Marfin ◽  
...  
Keyword(s):  
Density Functional ◽  
Quantum Chemical Study ◽  
Emission Spectra ◽  
Chemical Study ◽  
Functional Theory ◽  
Absorption And Emission ◽  
Absorption And Emission Spectra ◽  
Nir Dyes ◽  
Vibronic Couplings ◽  
Molecular And Electronic Structure

A comprehensive study of the molecular structure of aza-BODIPY and its derivatives, obtained by introduction of one or more substituents, was carried out. We considered the changes in the characteristics of the electronic and geometric structure of the unsubstituted aza-BODIPY introducing the following substituents into the dipyrrin core; phenyl, 2-thiophenyl, 2-furanyl, 3-pyridinyl, 4-pyridinyl, 2-pyridinyl, and ethyl groups. The ground-state geometries of the unsubstituted Aza-BODIPY and 27 derivatives were computed at the PBE/6-31G(d) and CAM-B3LYP/6-31+G(d,p) levels of theory. The time-dependent density-functional theory (TDDFT) together with FC vibronic couplings was used to investigate their absorption and emission spectra.

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