scholarly journals Synthesis and properties of bay unilaterally extended and mono-substituted perylene diimides

2019 ◽  
Vol 44 (1-2) ◽  
pp. 60-66 ◽  
Author(s):  
Fengxia Zhang ◽  
Xianqiang Huang ◽  
Xiaofeng Wei ◽  
Huixue Ren ◽  
Tianyi Jiang ◽  
...  
Keyword(s):  
Density Functional Theory ◽  
Density Functional ◽  
Molecular Orbitals ◽  
Perylene Diimide ◽  
X Ray Diffraction ◽  
Visible Absorption ◽  
Functional Theory ◽  
Perylene Diimides ◽  
The Density Functional Theory ◽  
Perylene Diimide Derivatives

The synthesis of two sulfur-decorated perylene diimides, the five-membered S-heterocyclic annulated perylene diimide (1) and 1-propanethiol- N,N′-dicyclohexylperylene-3,4,9,10-tetracarboxylic diimide (2), and a novel sulfoxide-containing perylene diimide, 1-propyl sulfoxide- N,N′-dicyclohexylperylene-3,4,9,10-tetracarboxylic diimide (3), are reported. The photophysical, electrochemical, aggregation, and thermal properties of these compounds are investigated by ultraviolet visible absorption, fluorescence, cyclic voltammetric, X-ray diffraction, and thermogravimetric analysis techniques. The geometries of the compounds are optimized at the 6-31G* level of theory using density functional theory, and their potentials are correlated with molecular orbitals. The prepared perylene diimide derivatives exhibit narrow the highest occupied molecular orbitals and the lowest unoccupied molecular orbitals band gaps, and they have quite different absorptions and emissions in dichloromethane solutions, which are in agreement with the density functional theory–calculated results.

Synthesis of [Re2Cl4(O)2(µ-O)(3,5-lut)4] and investigation of its structure via X-ray and spectroscopic measurements and DFT calculations

2014 ◽  
Vol 68 (5) ◽  
Author(s):  
Sławomir Michalik ◽  
Jan Małecki ◽  
Natalia Młynarczyk
Keyword(s):  
Density Functional Theory ◽  
Density Functional ◽  
Computational Study ◽  
Dft Method ◽  
Time Dependent ◽  
Electronic Transitions ◽  
X Ray Diffraction ◽  
Functional Theory ◽  
X Ray ◽  
The Density Functional Theory

AbstractA combined experimental and computational study of the dinuclear rhenium(V) complex containing (ReO)2(µ-O) core is presented in this article. The solid-state [Re2Cl4(O)2(µ-O)(3,5-lut)4] (3,5-lut = 3,5-dimethylpyridine) complex was characterised structurally (by single crystal X-ray diffraction) and spectroscopically (by IR, NMR, UV-VIS). The electronic structure was examined using the density functional theory (DFT) method. The spin-allowed electronic transitions were calculated using the time-dependent DFT method, and the UV-VIS spectrum was discussed.

scholarly journals Crystal Structure Determination of 4-[(Di-p-tolyl-amino)-benzylidene]-(5-pyridin-4-yl-[1,3,4]thiadiazol-2-yl)-imine along with Selected Properties of Imine in Neutral and Protonated Form with Camforosulphonic Acid: Theoretical and Experimental Studies

Materials ◽  
2021 ◽  
Vol 14 (8) ◽  
pp. 1952
Author(s):  
Agnieszka Dylong ◽  
Karolina Dysz ◽  
Krzysztof A. Bogdanowicz ◽  
Wojciech Przybył ◽  
Krzysztof A. Konieczny ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Density Functional Theory ◽  
Density Functional ◽  
Experimental Studies ◽  
Protonated Form ◽  
Molar Ratio ◽  
X Ray Diffraction ◽  
Functional Theory ◽  
The Density Functional Theory ◽  
Thermographic Camera

The crystal structure was determined for the first time for 4-[(di-p-tolyl-amino)benzylidene]-(5-pyridin-4-yl-[1,3,4]thiadiazol-2-yl)-imine (trans-PPL9) by X-ray diffraction. The imine crystallized in the monoclinic P21/n space group with a = 18.9567(7) Å, b = 6.18597(17) Å, c = 22.5897(7) Å, and β = 114.009(4)°. Intermolecular interactions in the PPL9 crystal were only weak C−H∙∙∙N hydrogen bonds investigated using the Hirshfeld surface. The electronic and geometric structure of the imine were investigated by the density functional theory and the time-dependent density-functional theory. The properties of the imine in neutral and protonated form with camforosulphonic acid (CSA) were investigated using cyclic voltammetry, UV–vis and 1H NMR spectroscopy. Theoretical and experimental studies showed that for the 1:1 molar ratio the protonation occured on nitrogen in pyridine in the PPL9 structure, as an effect of Brönsted acid–base interactions. Thermographic camera was used to defined defects in constructed simple devices with ITO/PPL9 (or PPL9:CSA)/Ag/ITO architecture. In conclusion, a thermally stable imine was synthesized in crystalline form and by CSA doping, a modification of absorption spectra together with reduction of overheating process was observed, suggesting its potential application in optoelectronics.

scholarly journals Electron-phonon interaction in In-induced √7 ×√3 structures on Si(111) from first-principles

2021 ◽  
Author(s):  
I. Yu. Sklyadneva ◽  
Rolf Heid ◽  
Pedro Miguel Echenique ◽  
Evgueni Chulkov
Keyword(s):  
Density Functional Theory ◽  
Double Layer ◽  
First Principles ◽  
Linear Response ◽  
Density Functional ◽  
Single Layer ◽  
Phonon Interaction ◽  
Functional Theory ◽  
Electron Phonon Interaction ◽  
The Density Functional Theory

Electron-phonon interaction in the Si(111)-supported rectangular √(7 ) ×√3 phases of In is investigated within the density-functional theory and linear-response. For both single-layer and double-layer √(7 ) ×√3 structures, it...

A DFT study of spherands containing five anisyl groups — Highly preorganized to bind the alkali metal

2006 ◽  
Vol 84 (8) ◽  
pp. 1045-1049 ◽  
Author(s):  
Shabaan AK Elroby ◽  
Kyu Hwan Lee ◽  
Seung Joo Cho ◽  
Alan Hinchliffe
Keyword(s):  
Density Functional Theory ◽  
Binding Energy ◽  
Density Functional ◽  
Ionic Radius ◽  
Binding Energies ◽  
Cavity Size ◽  
X Ray Diffraction ◽  
Functional Theory ◽  
X Ray ◽  
Good Agreement

Although anisyl units are basically poor ligands for metal ions, the rigid placements of their oxygens during synthesis rather than during complexation are undoubtedly responsible for the enhanced binding and selectivity of the spherand. We used standard B3LYP/6-31G** (5d) density functional theory (DFT) to investigate the complexation between spherands containing five anisyl groups, with CH2–O–CH2 (2) and CH2–S–CH2 (3) units in an 18-membered macrocyclic ring, and the cationic guests (Li+, Na+, and K+). Our geometric structure results for spherands 1, 2, and 3 are in good agreement with the previously reported X-ray diffraction data. The absolute values of the binding energy of all the spherands are inversely proportional to the ionic radius of the guests. The results, taken as a whole, show that replacement of one anisyl group by CH2–O–CH2 (2) and CH2–S–CH2 (3) makes the cavity bigger and less preorganized. In addition, both the binding and specificity decrease for small ions. The spherands 2 and 3 appear beautifully preorganized to bind all guests, so it is not surprising that their binding energies are close to the parent spherand 1. Interestingly, there is a clear linear relation between the radius of the cavity and the binding energy (R2 = 0.999).Key words: spherands, preorganization, density functional theory, binding energy, cavity size.

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.

A trinuclear chromium(III) chlorocarbyne

2021 ◽  
Author(s):  
Takashi Kurogi ◽  
Keiichi Irifune ◽  
Takahiro Enoki ◽  
Kazuhiko Takai
Keyword(s):  
Density Functional Theory ◽  
Density Functional ◽  
Terminal Alkynes ◽  
Functional Theory ◽  
The Density Functional Theory

Reduction of CCl4 by CrCl2 in THF afforded a trinuclear chromium(III) carbyne [CrCl(thf)2)]3(μ3-CCl)(μ-Cl)3. The chlorocarbyne complex reacted with aldehydes to afford chloroallylic alcohols and terminal alkynes. The density functional theory...

Density functional theory investigation of the effect of axial coordination and annelation on the absorption spectroscopy of nickel(II) and vanadyl porphyrins relevant to bitumen and crude oils

2013 ◽  
Vol 91 (9) ◽  
pp. 872-878 ◽  
Author(s):  
Stanislav R. Stoyanov ◽  
Cindy-Xing Yin ◽  
Murray R. Gray ◽  
Jeffrey M. Stryker ◽  
Sergey Gusarov ◽  
...  
Keyword(s):  
Density Functional Theory ◽  
Density Functional ◽  
Polyaromatic Hydrocarbons ◽  
Geometry Optimization ◽  
Soret Band ◽  
Heavy Oils ◽  
Visible Absorption ◽  
Functional Theory ◽  
Axial Coordination ◽  
Td Dft

The vanadium and nickel components in heavy oils and bitumen are important impurities in catalytic processing and form aggregates with other asphaltene components. Metalloporphyrins are commonly analyzed using the characteristic Soret band in the UV–vis absorption spectrum. However, the Soret band of metalloporphyrins in petroleum is broadened and weaker than expected based on the concentration of Ni and V in heavy oils and the extinction coefficients of isolated porphyrins. We hypothesize that the low intensity and broadening of the Soret band could be due to axial coordination of the metal center or fusion (annelation) of aromatic rings on the porphyrin π-system. This hypothesis is examined using the density functional theory for geometry optimization and time-dependent density functional theory (TD-DFT) for calculation of excited states of nickel(II) and vanadyl porphyrins with axially coordinated ligands and annelated polyaromatic hydrocarbons. Predictions of the excited electronic states performed using the tandem of TD-DFT and conductor-like polarizable continuum model of solvation support this hypothesis and provide insight into the extent of Soret band broadening and intensity decrease due to coordination and annelation. These computational results, validated with respect to visible absorption spectra, are important for understanding asphaltene aggregation and spectroscopic characterization and suggest methods for removal of transition metals from heavy oil.

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