scholarly journals DFT Calculations and Mesophase Study of Coumarin Esters and Its Azoesters

Crystals ◽  
2018 ◽  
Vol 8 (9) ◽  
pp. 359 ◽  
Author(s):  
M. Hagar ◽  
H.A. Ahmed ◽  
O.A. Alhaddadd
Keyword(s):  
Differential Scanning Calorimetry ◽  
Dft Calculations ◽  
Density Functional ◽  
Dipole Moments ◽  
Polarized Light ◽  
Alkoxy Group ◽  
Coumarin Derivatives ◽  
Scanning Calorimetry ◽  
Functional Theory ◽  
Azo Group

Two groups of coumarin derivatives, 4-methyl-2-oxo-2H-chromen-7-yl 4-alkoxybenzoates (coumarin esters), In, and 4-methyl-2-oxo-2H-chromen-7-yl 4-(2-(4-alkoxyphenyl)diazenyl) benzoates (coumarin azoesters), IIn, were synthesized and investigated for their mesophase behavior and stability. Each group constitutes five series that differ from each other by length of the mesogenic part. Within each homologous series, the length of the terminal alkoxy group varies between 6, 8, 10, 12 and 16 carbons. Mesophase behavior was investigated by differential scanning calorimetry (DSC) and identified by polarized light microscopy (PLM). Density functional theory (DFT) calculations for coumarin derivatives were discussed. The results revealed that the incorporation of azo group incorporated in the mesogenic core decreases the energy differences, increases the dipole moments and stabilities of coumarin azoesters series more than coumarin esters.

scholarly journals New Rod-Like H-Bonded Assembly Systems: Mesomorphic and Geometrical Aspects

Crystals ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 795
Author(s):  
Laila A. Al-Mutabagani ◽  
Latifah Abdullah Alshabanah ◽  
Hoda A. Ahmed ◽  
Khulood A. Abu Al-Ola ◽  
Mohamed Hagar
Keyword(s):  
Density Functional ◽  
Polarized Light ◽  
Proton Donor ◽  
Proton Acceptor ◽  
Scanning Calorimetry ◽  
Functional Theory ◽  
Ft Ir ◽  
Ir Spectroscopic ◽  
Thermal Stability Of ◽  
Bonded Complexes

Experimental and geometrical approaches of new systems of mesomorphic 1:1 supramolecular H-bonded complexes (SMHBCs) of five rings are discussed. The H-bonding between 4-alkoxyphenylimino benzoic acids (An, as proton acceptor) and 4-(4′–pyridylazophenyl) 4′′-alkoxybenzoates (Bm, as proton donor) were investigated. Mesomorphic behaviors were analyzed by differential scanning calorimetry (DSC) and mesophase textures were identified by polarized light microscopy (POM). H-bonded assembly was established by FT-IR spectroscopic measurements via Fermi band discussion. Thermal and theoretical factors were predicted for all synthesized complexes by density functional theory (DFT) predictions. The results revealed that all prepared complexes were monomorphic, with a broad range of smectic A phases with a high thermal stability of enantiotropic mesophase. Furthermore, DFT stimulations illustrated the experimental results in terms of the influence of the chain length either of the acid or the base component. Many parameters, such as the calculated stability, the dipole moment and the polarizability of the H-bonded complexes, illustrate how these parameters work together to enhance the smectic mesophases with the obtained stability and range.

scholarly journals Investigation of the Structures and Electronic Properties of 3'-(4-(5-Oxo-5-piperidin-1-yl)-penta-1,3-dienyl)benzo[d][1,3]dioxol-2-yl]Thymidine through DFT Calculations

2011 ◽  
Vol 3 (2) ◽  
pp. 339-345
Author(s):  
M. A. N. Al-Magmoy ◽  
A. H. Essa ◽  
A. J. Hameed
Keyword(s):  
Density Functional Theory ◽  
Dft Calculations ◽  
Electronic Properties ◽  
Ground State ◽  
Density Functional ◽  
Dipole Moments ◽  
Active Molecule ◽  
Functional Theory ◽  
Structural And Electronic Properties

The structural and electronic properties of 3'(4-(5-oxo-5-piperidin1-1-yl)penta-1,3-dienyl)benzo[d][1,3]dioxol-2-yl]-thymidine molecule have been investigated theoretically by performing density functional theory (DFT/3-21G*, 6-31G* and 6-31G**). The geometry of the molecule is optimized, and the electronic properties and relative energies of the molecules have been calculated by density functional theory in the ground state. The resultant dipole moments of the studied molecule are about 5.5, 6.36 and 7.35 Debyes by three levels (3-21G*, 6-31G* and 6-31G**, respectively). This property makes it an active molecule with its environment that is this molecule may interacts with its environment strongly in solution.Keywords:  3'-Azido-3'-deoxythymidine (AZT); Piperine; Density functional theory (DFT); Thymidine.© 2011 JSR Publications. ISSN: 2070-0237 (Print); 2070-0245 (Online). All rights reserved.doi:10.3329/jsr.v3i2.6364                J. Sci. Res. 3 (2), 339-345 (2011)

scholarly journals A DFT Study on the Stepwise Fluorinated Methylenecyclopropane ⇋ 1-Methylcyclopropene System

2008 ◽  
Vol 63 (1-2) ◽  
pp. 42-48 ◽  
Author(s):  
Salim M. Khalil
Keyword(s):  
Density Functional Theory ◽  
Free Energy ◽  
Dft Calculations ◽  
Density Functional ◽  
Dipole Moments ◽  
Isodesmic Reactions ◽  
Functional Theory ◽  
Substantial Concentration ◽  
Homo Lumo ◽  
Optimized Geometries

Density functional theory (DFT) calculations have been performed to calculate the optimized geometries of stepwise fluorinated methylenecyclopropanes and 1-methylcyclopropenes. Increasing the number of fluorine atoms caused a destabilization of methylenecycopropane. Perfluorinated 1-methylcyclopropene was found to be present in substantial concentration. This is supported by calculations of the Gibbs free energy, isodesmic reactions and orbital energies (HOMO-LUMO). These results are compared with the fluorinated cyclopropanes keto-enol system. Enthalpies, entropies and dipole moments are reported.

Three 1-phenylindolin-2-one derivatives displaying different molecular dipole moments and different crystallographic symmetries

2015 ◽  
Vol 71 (1) ◽  
pp. 69-74 ◽  
Author(s):  
Lei Wang ◽  
Man Zhang ◽  
Ying-Ying Jin ◽  
Qing Lu ◽  
Qi Fang
Keyword(s):  
Density Functional Theory ◽  
Dipole Moment ◽  
Dft Calculations ◽  
Density Functional ◽  
Dipole Moments ◽  
Polar Space ◽  
Functional Theory ◽  
Polar Structure ◽  
Molecular Dipole ◽  
Space Groups

Three 1-phenylindolin-2-one derivatives, namely 1-phenylindolin-2-one, C14H11NO, (I), 5-bromo-1-phenylindolin-2-one, C14H10BrNO, (II), and 5-iodo-1-phenylindolin-2-one, C14H10INO, (III), have been synthesized and their structures determined. Compounds (I) and (II) crystallized in the centrosymmetric space groupsPbcaandP21/c, respectively, while compound (III) crystallized in the polar space groupAea2. Density functional theory (DFT) calculations show that the molecular dipole moment gradually decreases in the order (I) > (II) > (III). The relatively smaller dipole moment of (III) and the larger non-electrostatic intermolecular interactions may be the main reasons for the noncentrosymmetric and polar structure of (III).

Thermal Decomposition of Hydroxylamine Nitrate Studied by Differential Scanning Calorimetry Analysis and Density Functional Theory Calculations

2017 ◽  
Vol 42 (4) ◽  
pp. 334-343
Author(s):  
Jianguo Liu ◽  
Zhentao An ◽  
Qian Zhang ◽  
Chaoyang Wang
Keyword(s):  
Activation Energy ◽  
Density Functional Theory ◽  
Differential Scanning Calorimetry ◽  
Thermal Decomposition ◽  
Density Functional ◽  
Probable Mechanism ◽  
Thermal Decomposition Mechanism ◽  
Scanning Calorimetry ◽  
Functional Theory ◽  
Mechanism Function

The thermal stability and kinetics of hydroxylamine nitrate (HAN) decomposition were studied by differential scanning calorimetry (DSC) and the thermal decomposition reaction mechanism was determined by density functional theory (DFT). With the help of parameter values from the non-isothermal DSC curves of HAN, the thermal decomposition activation energy and pre-exponential constant were obtained by the Kissinger and Ozawa methods. Then, the most probable mechanism function was calculated by the Šatava–Šesták method. Seven different paths for the thermal decomposition mechanism of HAN were formulated and DFT at the B3LYP/6-311++G(d,p) level was used to carry out the dynamics analysis. The calculated results show that the values of the activation energy calculated by the Kissinger and Ozawa methods are 67.892 and 70.412 kJ mol−1 respectively. The most probable mechanism function calculated by the Šatava–Šesták method is [Formula: see text]. The path being favoured energetically in the dynamics is in the order: Path6 > Path5 > Path4 > Path1 > Path2 > Path7 > Path3.

γ-Valerolactone-Introduced Controlled-Isomerization of Glucose for Lactic Acid Production over Sn-Beta Catalyst

2021 ◽  
Author(s):  
Xinpeng Zhao ◽  
Zhimin Zhou ◽  
hu luo ◽  
Yanfei Zhang ◽  
Wang Liu ◽  
...  
Keyword(s):  
Density Functional Theory ◽  
Lactic Acid ◽  
Dft Calculations ◽  
Acid Production ◽  
Density Functional ◽  
Lactic Acid Production ◽  
Hydrothermal Conversion ◽  
Functional Theory ◽  
Environment Friendly

Combined experiments and density functional theory (DFT) calculations provided insights into the role of the environment-friendly γ-valerolactone (GVL) as a solvent in the hydrothermal conversion of glucose into lactic acid...

Mechanistic understanding of the Cu(i)-catalyzed domino reaction constructing 1-aryl-1,2,3-triazole from electron-rich aryl bromide, alkyne, and sodium azide: a DFT study

2021 ◽  
Author(s):  
Hanlin Gan ◽  
Liang Peng ◽  
Feng Long Gu
Keyword(s):  
Density Functional Theory ◽  
Dft Calculations ◽  
Sodium Azide ◽  
Density Functional ◽  
Dft Study ◽  
Domino Reaction ◽  
Aryl Bromide ◽  
Functional Theory ◽  
Mechanistic Understanding

The mechanism of the Cu(i)-catalyzed domino reaction furnishing 1-aryl-1,2,3-triazole assisted by CuI and 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU) is explored with density functional theory (DFT) calculations.

Graph theory-based reaction pathway searches and DFT calculations for the mechanism studies of free radical-initiated peptide sequencing mass spectrometry (FRIPS MS): a model gas-phase reaction of GGR tri-peptide

2020 ◽  
Vol 22 (9) ◽  
pp. 5057-5069 ◽  
Author(s):  
Jae-ung Lee ◽  
Yeonjoon Kim ◽  
Woo Youn Kim ◽  
Han Bin Oh
Keyword(s):  
Graph Theory ◽  
Dft Calculations ◽  
Gas Phase ◽  
Density Functional ◽  
Reaction Pathway ◽  
Peptide Sequencing ◽  
Phase Reaction ◽  
Functional Theory ◽  
Fragmentation Mechanisms ◽  
Gas Phase Fragmentation

A new approach for elucidating gas-phase fragmentation mechanisms is proposed: graph theory-based reaction pathway searches (ACE-Reaction program) and density functional theory (DFT) calculations.

scholarly journals Density functional theory (DFT) calculations of VI/V reduction potentials of uranyl coordination complexes in non-aqueous solutions

2019 ◽  
Vol 21 (6) ◽  
pp. 3227-3241 ◽  
Author(s):  
Krishnamoorthy Arumugam ◽  
Neil A. Burton
Keyword(s):  
Density Functional Theory ◽  
Dft Calculations ◽  
Aqueous Solutions ◽  
Density Functional ◽  
Coordination Complexes ◽  
Dft Study ◽  
Redox Behavior ◽  
Functional Theory ◽  
Reduction Potentials ◽  
Uranium Complexes

Of particular interest within the +6 uranium complexes is the linear uranyl(vi) cation and it forms numerous coordination complexes in solution and exhibits incongruent redox behavior depending on coordinating ligands. This DFT study predicts VI/V reduction potentials of a range of uranyl(vi) complexes in non-aqueous solutions within ∼0.10−0.20 eV of experiment.

Sign in / Sign up

Export Citation Format

Share Document