scholarly journals Correlation between Quantumchemically Calculated LUMO Energies and the Electrochemical Window of Ionic Liquids with Reduction-Resistant Anions

2012 ◽  
Vol 2012 ◽  
pp. 1-6 ◽  
Author(s):  
Wim Buijs ◽  
Geert-Jan Witkamp ◽  
Maaike C. Kroon
Keyword(s):  
Density Functional Theory ◽  
Ionic Liquids ◽  
Quantum Chemical ◽  
Density Functional ◽  
Density Functional Theory Calculations ◽  
Lumo Energy ◽  
Functional Theory ◽  
Design And Optimization ◽  
Electrochemical Window ◽  
Excellent Method

Quantum chemical calculations showed to be an excellent method to predict the electrochemical window of ionic liquids with reduction-resistant anions. A good correlation between the LUMO energy and the electrochemical window is observed. Surprisingly simple but very fast semiempirical calculations are in full record with density functional theory calculations and are a very attractive tool in the design and optimization of ionic liquids for specific purposes.

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 Synthesis and investigation on optical and electrochemical properties of 2,4-diaryl-9-chloro-5,6,7,8-tetrahydroacridines

2021 ◽  
Vol 17 ◽  
pp. 2450-2461
Author(s):  
Najeh Tka ◽  
Mohamed Adnene Hadj Ayed ◽  
Mourad Ben Braiek ◽  
Mahjoub Jabli ◽  
Peter Langer
Keyword(s):  
Density Functional Theory ◽  
Cyclic Voltammetry ◽  
Density Functional ◽  
Energy Levels ◽  
Cross Coupling ◽  
Density Functional Theory Calculations ◽  
Facile Synthesis ◽  
Lumo Energy ◽  
Functional Theory ◽  
Homo Lumo

A facile synthesis of 2,4-diaryl-9-chloro-5,6,7,8-tetrahydroacridine derivatives is reported which is based on POCl3-mediated cyclodehydration followed by double Suzuki–Miyaura cross-coupling. The absorption and fluorescence properties of the obtained products were investigated and their HOMO/LUMO energy levels were estimated by cyclic voltammetry measurements. Besides, density functional theory calculations were carried out for further exploration of their electronic properties.

DFT study on [4+2] and [2+2] cycloadditions to [60] fullerene

2014 ◽  
Vol 68 (3) ◽  
Author(s):  
Ali Peyghan ◽  
Maziar Noei
Keyword(s):  
Density Functional Theory ◽  
Electron Emission ◽  
Density Functional ◽  
Energy Gap ◽  
Density Functional Theory Calculations ◽  
C60 Fullerene ◽  
Lumo Energy ◽  
Functional Theory ◽  
Reaction Energies ◽  
Homo Lumo

AbstractThe functionalisation of C60 fullerene with 2,3-dimethylene-1,4-dioxane (I) and 2,5-dioxabicyclo [4.2.0]octa-1(8),6-diene (II) was investigated by the use of density functional theory calculations in terms of its energetic, structural, field emission, and electronic properties. The functionalisation of C60 with I was previously reported experimentally. The I and II molecules are preferentially attached to a C—C bond shared and located between two hexagons of C60 via [4+2] and [2+2] cycloadditions bearing reaction energies of −15.9 kcal mol−1 and −72.4 kcal mol−1, respectively. The HOMO-LUMO energy gap and work function of C60 are significantly reduced following completion of the reactions. The field electron emission current of the C60 surface will increase after functionalisation of either the I or II molecule.

scholarly journals Formation of Interstellar Silicate Dust via Nanocluster Aggregation: Insights From Quantum Chemistry Simulations

2021 ◽  
Vol 8 ◽  
Author(s):  
Albert Rimola ◽  
Stefan T. Bromley
Keyword(s):  
Density Functional Theory ◽  
Quantum Chemical ◽  
Density Functional ◽  
Density Functional Theory Calculations ◽  
Spectroscopic Properties ◽  
Aggregation Process ◽  
Nucleation Process ◽  
Functional Theory ◽  
Astronomical Observations ◽  
Bulk Structures

The issue of formation of dust grains in the interstellar medium is still a matter of debate. One of the most developed proposals suggests that atomic and heteromolecular seeds bind together to initiate a nucleation process leading to the formation of nanostructures resembling very small grain components. In the case of silicates, nucleated systems can result in molecular nanoclusters with diameters ≤ 2 nm. A reasonable path to further increase the size of these proto-silicate nanoclusters is by mutual aggregation. The present work deals with modeling this proto-silicate nanocluster aggregation process by means of quantum chemical density functional theory calculations. We simulate nanocluster aggregation by progressively reducing the size of a periodic array of initially well-separated nanoclusters. The resulting aggregation leads to a set of silicate bulk structures with gradually increasing density which we analyze with respect to structure, energetics and spectroscopic properties. Our results indicate that aggregation is a highly energetically favorable process, in which the infrared spectra of the finally formed amorphous silicates match well with astronomical observations.

Sign in / Sign up

Export Citation Format

Share Document