Theoretical Study of Tautomeric Equilibrium, the Stability, Polarizability, HOMO-LUMO Analysis and Acidity of 4,4-diméthyl-3,4-dihydroquinolin-2(1H)-one Derivatives
Lucie Affoue Bede,
Benjamine Amon Assoma,
Latyfatou Laye Alao,
Denis Kicho Yapo,
Soleymane Kone
Issue:
Volume 7, Issue 2, December 2019
Pages:
107-114
Received:
13 August 2019
Accepted:
28 August 2019
Published:
11 September 2019
Abstract: Quinoline derivatives have several reactionnels sites conferring them a hight reactivity. This makes them excellent precursors in the synthesis of new bioactive compounds. Considering the interest of quinoline chemistry and diversity of their applications, a study based on a theoretical approach of reactivity of 4,4-dimethyl-3,4-dihydro-quinolin-2(1H)-one and derivatives is carried. This study determines interaction sites of these derivatives in order to understand the mechanisms involved. Calculations are carried in gaseous phase and solution in N, N-dimethylformamide (DMF). Density Functional Theory (DFT/B3LYP) method associated with 6-311G(d) and 6-311+G (d) bases is used to perform these calculations. Results of the thermodynamic parameters showed that there is a tautomeric equilibrium relationship between the different derivatives Reactivity analysis based on Frontier Molecular Orbitals theory revealed that tautomers ketone are less reactive than tautomers enol. Calculation of Fukui indices indicates that the carbon atoms C2, C3, C5, C 7 and C8 of quinoline-2-one ring are sites favorable to nucleophilic attack. Atoms N1, C4, C6 and O11 are nucleophilic sites therefore favorable to an electrophilic attack. Methoxyl substituent (CH3O) decreases the acidity of nitrogen and oxygen atoms of quinolin-2-one while bromine atom increases acidity of these same sites. These results predict a deprotonation of the nitrogen (N1) of the brominated quinoline-2-ones less energetic than that of the methoxylated derivatives. Conclusively, this work provides data to elucidate the mechanisms to understand the reactivity of 4,4-diméthyl-3,4-dihydroquinolin-2(1H)-one derivatives.
Abstract: Quinoline derivatives have several reactionnels sites conferring them a hight reactivity. This makes them excellent precursors in the synthesis of new bioactive compounds. Considering the interest of quinoline chemistry and diversity of their applications, a study based on a theoretical approach of reactivity of 4,4-dimethyl-3,4-dihydro-quinolin-2(...
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Topological Analysis of the Electron Density Illustrating the Stabilizing Interactions in Some Basic Solid-state Systems
James Tembei Titah,
Franklin Che Ngwa,
Peter Sirsch,
Coulibaly Wacothon Karime,
Mamadou Guy-Richard Kone
Issue:
Volume 7, Issue 2, December 2019
Pages:
115-120
Received:
31 October 2019
Accepted:
21 November 2019
Published:
7 December 2019
Abstract: The solid-state structures of Sodium (Na), Titanium (Ti), Diamond and Graphite, Sodium Chloride (NaCl), Magnesium Oxide (MgO), Cadmium (II) Iodide (CdI2) and Zirconium Chloride (ZrCl) have been explored in details using computational electron density methods; the full-potential linearized augmented plane wave (FPLAPW) method plus local orbital (FPLAPW+lo) embodied in the WIEN2k package code. Topological analysis of their DFT-computed electron densities in tandem with Bader’s Atoms in Molecules (AIM) theory reveals a plethora of stabilizing interactions some of which are really strong. Na and Ti metals reveal only metallic bonding, diamond and graphite show covalent bonding between the carbon-atoms. In addition, there exist Van der Waals forces between the carbon-atoms on adjacent planes in the graphene sheets. NaCl and MgO exhibit electrostatic interactions between the metals (Na, Mg) and non-metals (Cl, O) respectively. Furthermore, there exist Van der Waals interactions between Cl and O atoms. CdI2 and ZrCl both show ionic and Van der Waals forces between the atoms. ZrCl exhibit metallic bonding and NNMs between the Zr-atoms, which are absent in CdI2 due to longer Cd-Cd bond distances. Analyses of the electron density flatness (f), charge transfer index (c) and molecularity (μ) were computed. It is observed that the different types of interactions increase with complexity of the solid-state structures. Finally, non-nuclear maxima (NNM) were identified for the first time in heteroatomic solid-state systems.
Abstract: The solid-state structures of Sodium (Na), Titanium (Ti), Diamond and Graphite, Sodium Chloride (NaCl), Magnesium Oxide (MgO), Cadmium (II) Iodide (CdI2) and Zirconium Chloride (ZrCl) have been explored in details using computational electron density methods; the full-potential linearized augmented plane wave (FPLAPW) method plus local orbital (FPL...
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