Yazar "Brahmia, Ameni" seçeneğine göre listele

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    Synthesis, crystal structure, Hirshfeld surface analysis and DFT calculations of 2, 2, 2-tribromo-1-(3,5-dibromo-2-hydroxyphenyl)ethanone
    (Elsevier, 2022) Brahmia, Ameni; Bejaoui, Linda; Rolicek, Jan; Hassen, RachedBen; Serdaroglu, Goncagul; Kaya, Savas
    A novel derivative 2, 2, 2-tribromo-1-(3,5-dibromo-2-hydroxyphenyl) ethanone was synthesis by 3-acetyl-4-hydroxycoumarin and dibromide. The structural properties of the synthesized compound have been exploited with the aid of single-crystal X-ray crystallographic studies and infrared spectrometry. The compound crystallizes in the monoclinic system with space group P2(1)/c. A comparative study between the novel brominated compound synthesized and the brominated coumarin derivative is presented. The optimized DFT geometries (B3PW91/6-311 G (2df, p)) and the spectral simulations of two derivatives compared agree well with the experimental data. Hirshfeld's analysis revealed the importance of Br center dot center dot center dot Br (40%) and Br center dot center dot center dot H/H center dot center dot center dot Br (19%) of the total surface contacts in the molecular stack. The contacts O center dot center dot center dot H/H center dot center dot center dot O have a significant contribution for the brominated coumarin (C2) of 26.1% of SH compared to the brominated cycle (C1) 9.7%. (C) 2021 Published by Elsevier B.V.
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    Synthesis, crystal structure, hirshfeld surface analysis, spectroscopic, biological and first-principles studies of novel aminocoumarins
    (Elsevier, 2020) Bejaoui, Linda; Brahmia, Ameni; Marzouki, Riadh; Dusek, Michal; Eigner, Vaclav; Serdaroglu, Goncagul; Kaya, Savas
    Two novel aminocoumarins 3-(1-(2 aminophenylamino) ethylidene)chromene-2,4-dione, noted (1) and 3-(1-(2-1-(2, 4-dioxochromene-3-ylidene) ethylamino)phenylamino) ethylidene) chromene-2,4-dione,noted (2), were synthesized from 3-acetyl-4-hydroxycoumarin and ortho-phenylenediamine in absolute ethanol and characterized by spectroscopies methods (FT-IR, UV-vis and fluorescence). The crystal structures of the mentioned compounds were solved from single-crystal diffraction data at low temperature. The compound (1) crystallizes in the orthorhombic system with space group Iba2 while (2) is monoclinic with space group P(2)1/c . Hirshfeld surface analysis indicates the presence of the pi-pi stacking in the aminocoumarin structures with the contribution of 7.8% for (1) and 8.7% for (2) of the total Hirshfeld area. The optimized DFT geometries (B3PW91/6-311 G (2df, p)) and the spectral simulations agree well with the experimental data. Theoretical reactivity behavior was assessed, taking into account HOMOLUMO diagrams and Molecular Electrostatic Potential maps. The two aminocoumarins derivatives have fluorescence properties. Analysis of the photoluminescence spectra shows that the emission intensity is high for the solutions of the two compounds in polar aprotic solvents (DMSO, DMF). The aminocoumarins were monitored for antimicrobial activity using the disk diffusion method. The coumarin (1) is effective against S. aureus (gram-positive bacteria) and S. typhy (gram-negative bacteria), but the coumarin (2) showed markedly weak antibacterial activity. (C) 2020 Elsevier B.V. All rights reserved.
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    Theoretical and experimental insights about the adsorption of uranyl ion on a new designed Vermiculite-Polymer composite
    (Elsevier, 15.04.2022) Şimşek, Selçuk; Kaya Savaş; Şenol, Zeynep Mine; Ulusoy, Halil İbrahim; Katim, Kp; Özer, Ali; Altunay Nail; Brahmia, Ameni
    A new Polyacrylamide (PAA)-Vermiculite (V) composite was synthesized and characterized with the help of FTIR, SEM, and PZC analyses. The effects of ion concentration, pH and ionic strength parameters to adsorption process were investigated in detail. The obtained data were analyzed and discussed in the light of the Langmuir, Freundlich and Dubinin-Radushkevich (DR) models. It was shown that the adsorption of UO22+ increased with the increasing of the pH while the increasing or decreasing of the ionic strength did not lead to significant changes in adsorption process. The adsorption of uranyl ion on new designed material followed an endothermic and spontaneous process with increased disorderliness at adsorbate/adsorbent interface. It was noticed that the adsorption process exhibits a pseudo-second-order kinetics. The interaction mechanism regarding to the interaction between uranyl ion and new designed Polyacrylamide (PAA)-Vermiculite (V) composite was highlighted in the light of Density Functional Theory (DFT) calculations. Both theoretical and experimental analyses made proved that the designed new material with a adsorption capacity of 0.375 mol kg−1 is a potential adsorbent for effective removal of uranyl ions from solutions.