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Öğe A pH-dependent CT sensitive method for detection of trace Mn in milk by UV-spectrophotometry(1 September 2023) Zengin HacıbayramIn this study, a new method was developed for the extractive pre-concentration/detection of trace Mn in milk prior to analysis by UV-spectrophotometry. The method is based on the pH-controlled intra-ligand charge transfer (ICT) complexation of modifier, 2-HBT in presence of trace Mn (II), and then the extraction of the complexes, where the hydrazine and hydrazone tautomers are predominant at pHs of 2.0/ 3.0, and pH 6.0 because of CT at pH 4.0. The free Mn (II) and total Mn levels of the samples were detected at 269 nm by UVspectrophotometry. For total Mn, the method was validated by analysis of two certified milk samples. The results were statistically in good agreement with the certified values, and the precision was lower than 6.4%. After a pre-concentration of 62.5-fold, the limits of detection were 1.45/1.92 and 1.54/2.12 μg L 1 in range of 5–165 and 5–150 μg L 1 from the solvent-based and matrix-matched calibration curves, respectively. There is not a matrix effect from comparison of the calibration curves’s slopes. The method was successfully applied to analysis of milk samples. In terms of speciation, the free Mn (II) and total Mn levels in milk were in the range of 7.65–30.4 μg L 1, and 10.2–34.7 and 10.7–35.5 μg L 1 after the microwave and ultrasound assisted extraction.Öğe Novel amide- and imide-co-polymers modified with sulfathiazole as efficient chelator for selective extraction, pre-concentration and determination of trace inorganic antimony (as Sb(III)) from edible vegetable oils by ultrasound assisted-cloud point extraction coupled to micro-volume UV-spectrophotometry(Elsevier, 22 September 2022) Zengin Hacıbayram; Gürkan RamazanThe study described the synthesis, characterization, and application of newly prepared sulfathiazole-modified amide/imide co-polymers for the extraction of trace Sb(III) from edible vegetable oils. The method was based on the pH-dependent complexation between Sb(III) and chelators as a result of charge transfer via tautomerization in presence of the mixed ionic surfactants in 5%(v/v) 2-propanol, 1:1, v/v) at pH 2.0 and 8.0, respectively for amide and imide copolymers and then selectively ultrasound assisted-cloud point extraction of the Sb(III)- complexes into the micellar phase of extractant. The separated micellar phase by centrifugation was diluted to 0.4 mL with tetrahydrofuran, and detected at 269 nm by micro-volume UV-spectrophotometry. The parameters affecting extraction efficiency were optimized. The optimal extraction conditions were found to be: 0.6/0.8 mmol L 1 of McIlvaine buffer, 30 μmol L 1 of the mixed-ionic surfactant mixture, 120 μmol L 1 KCl, 0.1/0.06% (v/v) of the nonionic surfactant and (0.4/0.2)× 10 3%(w/v) of sulfathiazole-modified amide/imide copolymers at pH 2.0 and 8.0 for 7 min at 40 ◦C in an ultrasonic bath (40 kHz, 300 W). From preconcentration of 20-mL sample, the good linear relationships (r2 ≥0.995) between absorbance and Sb(III) concentration were obtained from calibration curves prepared in solvent in range of 1–40 and 1–62.5 μg L 1 with the method detection limits of 0.30/0.47 and 0.51/0.51 μg L 1 at 269 nm by spectrophotometer after 50-fold pre-concentration. The accuracy was statistically verified by analysis of a non-certified sample with and without spiking where the precision and relative recoveries are within 5–12% and 83–92%, respectively. Also, the matrix effect was evaluated by triplicate measurements of 25 μg L 1 Sb(III) (n: 3) under optimal conditions. The method was successfully applied into the analysis of total iSb levels of edible vegetable oils. The results shown that the STZmodified amide/imide co-polymers were efficient selective chelators even in presence of 50-fold excess Sb(V), and exhibited great potential as alternative binding chelators for the extraction of Sb(III) from edible vegetable oils.Öğe A new pre-concentration procedure based on poly(styrene-co-maleamide and imide) copolymers modified with 2-hydrazinobenzothiazole prior to spectrophotometric monitoring of inorganic as (as As(III)) in edible vegetable oils(Elsevier, 27 December 2022) Zengin, HacıbayramThis study describes the development of 2-hydrazinobenzothiazole modified-amide/imide co-polymers for the extraction/pre-concentration of trace As(III), from edible vegetable oils. Their characterization was realized by help of instrumental techniques. The method is based on pH-dependent complexation between As(III) and copolymeric chelators in presence of 35-fold excess As(V), their selective extraction into the mixed micellar phase, and detected at pH 2.0 and 6.0 by UV–vis spectrophotometer. The variables affecting extraction efficiency were optimized. From pre-concentration of 20-mL sample, the good linear relationships were obtained in range of 1–40 and 3–75 μg/L with DLs of 0.32 and 1.00 μg/L. The accuracy was verified by analysis of a certified sample without and with spiking. The method was applied into the analysis of iAs levels of samples. The results show that the functional co-polymers are efficient chelators, and exhibit great potential for the selective extraction of As(III) from edible vegetable oils.Öğe Molecular insights into the corrosion inhibition mechanism of omeprazole and tinidazole: a theoretical investigation(2023)In many studies published in recent years, corrosion scientists proved that various drug molecules can exhibit high inhibition performance against the corrosion of metal surfaces and alloys. This study presents the adsorption behaviour and inhibition mechanism of Omeprazole and Tinidazole on steel surface in gas phase and aqueous acidic conditions using quantum chemical calculations and molecular dynamics simulations. Well-known quantum chemical parameters such as EHOMO, ELUMO, energy gaps, dipole moment, global hardness, softness, electrophilicity, electrodonating power, electroaccepting power and the fraction of electron transfer, were calculated to understand the corrosion inhibition properties and interactions with the steel surface of the studied molecules. Fukui indices analysis was performed to identify the local reactivities of the molecules. Additionally, Monte Carlo simulations were used to determine the optimal adsorption configuration of the inhibitors onto a Fe (1 1 0) surface. The study's findings provide valuable insights into preventing corrosion of steel surfaces in aqueous acidic environments. The theoretical data obtained was evaluated in terms of Maximum Hardness, Minimum Polarizability and Minimum Electrophilicity Principles.Öğe Molecular docking and A DFT study on the antiradical activity of naringenin and hesperetin with nitric oxide, peroxy, and methoxy radicals(2023) Özbakır Işın, Dilara; Erdoğan, ŞabanNaturally occurring flavonoids, naringenin (N) and hesperetin (H), weretheoretically investigated for their ability to scavenge nitric oxide, peroxy,and methoxy radicals in gas, water, and benzene solvent media.BMK/6-311+G(d,p) level of theory was used to for determine antiradical activ-ity of the selected compounds and the calculation of reaction enthalpies relatedto three possible mechanisms of free radical scavenging activity, namely,hydrogen atom transfer (HAT), single electron transfer–proton transfer(SET-PT), and sequential proton loss electron transfer (SPLET). When theresults were examined, it was seen that the SET-PT mechanism was not aneffective antioxidant effect mechanism in any solvent medium. In addition, inthe absence of any radicals, HAT in the gas phase, SPLET in the water phase,and HAT and SPLET in the benzene phase are in competition. When theinvestigated antioxidants were examined in the presence of various radicals interms of their antiradical scavenging properties, it was observed that theSET-PT mechanism was not possible in all radicals and all solvent phases dueto positive ionization potential (IP) values. In addition, it was determined thatthe SPLET mechanism pathway was the most likely mechanism pathway withall the radicals examined. In addition, molecular docking calculations of thestudied molecules were made to compare the activities against to humanperoxiredoxin-5 (HP5), a protein with antioxidant properties.Öğe Chemical composition, antimicrobial activities, and molecular docking studies of Turkish propolis ethanol extract(CAAS Agricultural Journals, 2023) Ozbey, G; Muz, M. N.; Tanriverdi, E. S.; Erkan Sultan; Bulut, N.; Otlu, B.; Zigo, F.The purpose of the present study was to investigate the antimicrobial effect of propolis ethanol extract collected from the Tarsus district of Mersin province, Kilis province, Yayladagi district of Hatay province in southern Türkiye and Sarkoy district of Tekirdag province of northwestern Türkiye against Escherichia coli (ATCC 25922), Helicobacter pylori (ATCC 43504), Pseudomonas aeruginosa (ATCC 27853), and Staphylococcus aureus (ATCC 29213). Their chemical constituents were detected via liquid chromatography-mass spectrometry/mass spectrometry (LC-MS/MS). They were used in a molecular docking approach to search the interactions between the propolis compounds. A total of 24 phenolic compounds were detected in all samples. 3–4 dimethoxycinnamic acid, caffeic acid and genistein were indicated to be the predominant phenolic compounds in propolis extracts by LC-MS/MS, while rutin was found in the lowest concentration. Phenolic compounds were detected in a high concentration of the propolis samples collected from the Tarsus district of Mersin province. The broth microdilution method determined minimum inhibition concentration (MIC) values. MIC values ranged from 0.02 to 14 mg·mL–1. E. coli and S. aureus examined were as susceptible to the propolis extracts except for Mersin and Tekirdag propolis samples. The propolis sample collected from the Tarsus district of Mersin province presented the highest antibacterial activity on P. aeruginosa with MIC values of 1 mg·mL–1. Active substances in propolis were docked to the relevant target proteins (5LMM, 4NX9, 5YHG, and 5FXT) representing E. coli (ATCC 25922), H. pylori (ATCC 43504), P. aeruginosa (ATCC 27853), and S. aureus (ATCC 29213), and with the help of molecular simulation. With this study, we indicated that the ethanol extract of propolis had a stronger antibacterial activity on S. aureus isolates than that of E. coli, H. pylori, and P. aeruginosa. Although each component of propolis contributed to the antibacterial activity, the contribution of the vitexin component to the antibacterial activity was found to be quite significant.Öğe Synthesis, docking studies, in vitro cytotoxicity evaluation and DNA damage mechanism of new tyrosine-based tripeptides(Wiley, 2023) Çalışkan Eray; Kaplan, A.; Şekerci, G.; Çapan, İ.; Tekin, S.; Erkan Sultan; Koran Kenan; Sandal Süleyman; Görgülü, A. O.Peptides are one of the leading groups of compounds that have been the subject of a great deal of biological research and still continue to attract researchers' attention. In this study, a series of tripeptides based on tyrosine amino acids were synthesized by the triazine method. The cytotoxicity properties of all compounds against human cancer cell lines (MCF-7), ovarian (A2780), prostate (PC-3), and colon cancer cell lines (Caco-2) were determined by the 3-[4,5-dimethylthiazol-2-yl]-2,5 diphenyl tetrazolium bromide assay method, and % cell viability and logIC50 values of the compounds were calculated. Significant decreases in cell viability were observed in all cells (p < 0.05). The comet assay method was used to understand that the compounds that showed a significant decrease in cell viability had this effect through DNA damage. Most of the compounds exhibited cytotoxicity by DNA damage mechanism. Besides, their interactions between investigated molecule groups with PDB ID: 3VHE, 3C0R, 2ZCL, and 2HQ6 target proteins corresponding to cancer cell lines, respectively, were investigated by docking studies. Finally, molecules with high biological activity against biological receptors were determined by ADME analysis.Öğe Bromination and conversion of tetrahydro-1H-indene to bisoxirane with a new approach: synthesis, structural characterization by spectroscopic and theoretical methods, and biological analysis supported by DFT and docking(TÜBİTAK, 2023) YILMAZ, R. F.; Erkan Sultan; ÖKTEN, S.; Tutar, A.; ŞAHİN, E.In this study, a new method for synthesizing diepoxides is proposed. Tetrahydroindene 1 was brominated with NBS in the presence of LiClO4 and acetic acid, resulting in the formation of dibromodiacetate derivatives 2 and 3. Treatment of compounds 2 and 3 with NaOH in methanol produced a mixture of diepoxides 4 and 5. Additionally, direct bromination of tetrahydro-1H-indene yielded tetrabromo octahydroindene isomers 6 and 7. The structures of the compounds were characterized using spectroscopic techniques such as 1H NMR, 13C NMR, APT, COSY, and XRD. The new method provides an easy and selective route to access epoxides for the synthesis of various chemicals. This study also highlights the selective formation of endo-exo and exo-exo orientations of the obtained diepoxides, distinguishing it from previous studies. The stability and properties of the stereoisomers were investigated using computational methods, revealing the most stable configurations. Reactive sites in the molecules were identified using contour diagrams and molecular electrostatic potential maps. The anticancer properties of the compounds were evaluated in silico, comparing them to 5-fluorouracil (5-FU) against several cancer cell lines. The compounds exhibited the most effective anticancer activity against MCF-7 cells, with the order of anticancer activities generally determined as 2 > 7 > 3 > 6 > 5 > 4 > 5-FU.Öğe Equilibrium and Computational Chemical Modelling Studies for the Removal of Methyl Orange and Methyl Red Dyes from Water Using Modified Silica Resin(Taylor & Francis, 2023) Junejo, R; Shams Jalbani; Kaya,Savaş; Erkan Sultan; Marzouki, R; Memon, S.This study describes the removal of methyl orange (MO) and methyl red (MR) dyes from water samples using morpholinomethylcalix[4]arene immobilised silica (MIS) resin. The silica surface has been modified by p-morpholinomethylcalix[4]arene moiety and was characterised by FT-IR spectroscopy and SEM techniques. The adsorption capacity of MIS-resin was checked through batch adsorption experiments under the optimised conditions of pH, MIS-resin dose, time, and temperature. Results show that adsorption of MO and MR dyes are highly affected by the change in pH; thus, the higher adsorption percentages were achieved at pH 5.3 and 6.6 respectively. The adsorbent dosage has been optimised and it was noticed that the maximum adsorption was achieved by using 40 mg.L−1 of MIS-resin dose. The adsorption rate of dyes was investigated by applying the pseudo-first and second-order kinetic models and it has been observed that the experimental data shows a better correlation coefficient with the pseudo-second-order kinetic model. The feasibility of adsorption was analysed by thermodynamic parameters such as ∆H°, ∆G°, and ∆S° values indicate that the adsorption of dyes is exothermic and spontaneous. The equilibrium data have been validated using Langmuir and Freundlich models and the Langmuir model has a good correlation coefficient (R2 0.99). The MIS-resin was applied onto industrial effluents and it has been observed that the prepared resin is a very efficient adsorbent for the treatment of dyes contaminated wastewater. The adsorption of MO and MR dyes onto MIS-resin was well defined by computational chemical modelling at the B3LYP/LANL2DZ/6-311++G (d,p) level using G09W software.Öğe Modeling, spectroscopic structural properties of platinum-II complexes of 2-((phenylimino)methyl)phenolate-based ligands and research of nonlinear optical, organic light emitting diode and solar cell performances(Elsevier, 2023) Erkan Sultan; Karakaş, DuranThe hypothetical Pt(B1)2, Pt(B2)2 and Pt(B3)2 complexes were modeled. B1, B2 and B3 are Schiff bases, 2-((phenylimino)methyl)phenolate, 4-methyl-2-((phenylimino)methyl)phenolate and 4-nitro-2-((phenylimino)methyl)phenolate, respectively. The ground state structures of the complexes were computed at the DFT-B3LYP/6–31 G(d)/LANL2DZ level. From the characteristic bond lengths, bond angles, bond stretching frequencies and proton chemical shift values, the platinum environment geometry was found to be square plane. The nonlinear optical (NLO) activities of the complexes were investigated by calculating some nonlinear optical property parameters and NLO performance of Pt(B3)2 was found to be higher than other complexes. Organic light emitting diode (OLED) performances of the complexes were investigated and found that the all complexes could be suitable for the production of OLED-featured materials. The solar cell (SC) performances of the complexes were determined by considering the power conversion efficiency (PCE). it was suggested that the Pt(B3)2 complex might have the highest solar cell performance.Öğe Analysis of boronic acids containing amino ferrocene by DFT approach and in silico studies(Elsevier, 2023) Muhammad, U. S.; Erkan Sultan; Kaya,SavaşThe synthesized (2)-(6) complexes and (2′)-(6′) hypothetical complexes formed by attached boranic acid esters were optimized at the DFT-B3LYP/GEN level. The structural and spectroscopic properties (IR, 1HNMR , 13CNMR ) of the optimized complex structures were calculated and the complexes were characterized. Molecular orbital energy diagrams and some molecular properties of the complexes were calculated. Some quantum chemical parameters were calculated for the biological activities of the complexes. It was predicted that complexes with diboranic acid ester had higher biological abilities. They were docked against Burkitt's lymphoma (BL) cell line for their anticancer activities and similar trend was obtained with quantum chemical parameters. NLO and OLED properties were examined to evaluate the electronic properties of the complexes. These properties of the complexes were found to be advantageous over the related reference materials.Öğe Investigation of substituent effect on rhenium complexes by DFT methods: Structural analysis, IR spectrum, quantum chemical parameter, NLO and OLED properties, molecular docking(Elsevier, 2023) Yıldız Alkaya, C.; Güney, E.; Nasif, V.; Karakaş, D.; Erkan SultanFor the synthesized 9b, 9c and 9d complexes, hypothetical complexes were formed by adding electron-withdrawing (NO2) and electron-donating (NH2) groups. Benchmark analysis was performed using the bond lengths of the synthesized complexes (9b, 9c and 9d). B3LYP-LANL2DZ/6-31+G(d), B3LYP-LANL2DZ/6-31G(d), B3LYP-SDD/6-31+G(d), B3LYP-SDD/6-31G(d), M062X-LANL2DZ/6-31+G(d), M062X-LANL2DZ/6-31G(d), M062X-SDD/6-31+G(d) and M062X-SDD/6-31G(d) levels were used for these analysis. According to the correlation coefficient, the best level was determined as M062X-SDD/6-31+G(d). IR spectra of all complexes were examined in detail. Experimental results and calculation results for IR spectra were found to be in agreement with each other. The activities of the complexes were compared with the quantum chemical parameters. It was predicted that complexes containing electron donor groups are more advantageous in terms of biological activity. Electrophilic and nucleophilic regions for complexes were determined by molecular orbitals diagrams and electrostatic potentials maps. In addition, all complexes were evaluated in terms of their optical properties (NLO and OLED) and were found suitable for both materials. Experimentally, the 9b, 9c and 9d complexes were active against the A2780 ovarian cancer cell lines. Therefore, molecular docking was performed with the selected protein (PDB ID: 5FI4) and all complexes. The obtained computational results were found to be in agreement with the experimental data.Öğe A series of phenanthroline-imine compounds: Computational, OLED properties and fluorimetric sensing of nitroaromatic compounds.(Elsevier, 2023) Kose, A.; Erkan Sultan; Tümer, M.In this study, Schiff base compounds (1–5) were synthesized by the reaction of 5-amino-1,10-phenanthroline with various aldehydes. The molecular structures of the synthesized compounds were characterized by FT-IR, 1H/13C NMR and mass spectroscopic methods. Single crystals of 1 were obtained and their molecular structures in crystalline form were determined by single crystal X-ray diffraction study. The sensor properties of the synthesized compounds against nitroaromatic compounds [nitrobenzene (NB), 4-nitrophenol (NP), 2,4-dintrophenol (DNP) and 1,3,5-trinitrophenol (TNP)] were investigated by fluorescence spectroscopy. Compound 3 have highest sensitivity for the sensing of 1,3,5-trinitrophenol (TNP) (Ksv: 4.63 × 104 M−1) with LOD of 4.01 µM while compound 5 showed the highest sensitivity for 2,4-dinitrophenol (DNP) (Ksv: 5.71 × 104 M−1) with LOD of 4.75 µM. In addition, the structural parameters (bond angles/lengths), contour diagrams of HOMO/LUMO molecular orbitals, molecular electrostatic potential (MEP) maps, non-linear optical (NLO) and OLED properties were investigated by computational studies. According to the HOMO and LUMO energies, the NLO property of the molecule (5) is higher than both other molecules and the reference substance urea.Öğe Crystal structure, Hirshfeld surface analysis, computational and antifungal studies of dihydropyrimidines on the basis of salicylaldehyde derivatives(2023)We herein reported the synthesis of dihydropyrimidines 1 and 2 on the basis of nitro and brominated salicylaldehyde derivatives by Biginelli reaction in microwave conditions in the presence of cheap low toxic copper triflate. The structures of both compounds were investigated by the X-ray single-crystal diffraction method. The presence of non-covalent interactions and their impact on crystal structure was determined. In addition, the conformation of the dihydropyrimidine ring was also studied. In order to understand the molecular interactions in their structure, the Hirshfeld surface and contacts enrichment analyses were performed. Moreover, the biological activity of synthesized compounds was also investigated against Candida albicans and Aspergillus niger fungi. Finally, computational studies of the related compounds were performed at M062X/6- 31G(d) level in the water and molecular docking calculations were done against the thymidylate kinase of Candida albicans.Öğe Eaton's reagent is an alternative of PPA: Solvent free synthesis, molecular docking and ADME studies of new angular and linear carbazole based naphtho naphthyridines(2023)An approach towards the preparation of novel angular and linear carbazole based naphtho naphthyridines are described in good yields. From schematic study on the condensation of 4-chloro-2- methylbenzo[h]quinoline and 3-amino-9-ethylcarbazole in presence of CuI as catalyst to N-(9-ethyl- 9H-carbazol-3-yl)-2-methylbenzo[h]quinolin-4-amine was stated as starting synthon. Thus, this carbazole based quinoline amine on treatment with Eaton's reagent catalyzed cyclisation reaction with Aromatic carboxylic acids to yield the linear and angular 8-substituted naphtho[h]carbazol [1,6] naphthyridines. This Eaton's reagent is a precise catalyst for the reaction of cyclizing cum aromatization agent followed by dehydration of the conversion of angular and linear naphthyridines in excellent yields compared with Polyphosphoric acid (PPA). Further, the molecular docking studies were conducted to offer binding mode into the binding sites of phosphoinositide-dependent protein kinase 1 (PDK-1) receptors. The synthesized compounds showed better docking scores and binding energies, when compared with reference drugs ARC-111 and Ellipticine. Pharmacokinetic (ADME) parameters of the potent derivatives have also been found to an acceptable range.Öğe New azo-azomethine based copper(II) and zinc(II) complexes: Synthesis, electrochemistry, photoluminescence properties, density functional theory calculations and molecular docking(2023)A new bidentate azo-azomethine ligand 2-{(E)-[(3,4-dimethylphenyl) imino]methyl}-4-[(E)-(4-ethylphenyl)diazenyl] phenol (2) and its copper(II) and zinc(II) complexes (3) and (4) were synthesized and characterized by elemental analysis, 1H/13C NMR (for the ligand 2 and its Zn(II) complex) and IR spectral measurements. The structure of the ligand 2 was also determined by single crystal X-ray diffraction. The structure was solved in monoclinic unit cell and P21/n space group with final R value of 0.0586. In the structure of the ligand, the imine (CH–– N) bond distance is of 1.276(2) Å which confirms the phenol-imine tautmeric form in the crystalline state. In the structure, molecules are stacked by π-π (edge to edge) interactions. The electrochemical and photoluminescence properties of the synthesized azo-azomethine ligand and its metal complexes were investigated. Also, computational studies of related compounds were performed by using M062X/6-31+G level in vacuum. The potential VEGFR2 inhibitory properties of the synthesized ligand and its possible tautomers was investigated by the docking study. As for the ligand structures, azo-imine form is so reactive against the VEGFR2 protein and its docking score and total interaction energy are better than those of other tautomers.Öğe [Cu 2 (ox)(dien) 2 ](NO 3 ) 3 , a precursor for preparation of CuO nanoparticles: Synthesis, structural, Hirshfeld surface analyses, and physico-chemical investigations(2023)[C u 2 ( ox )( dien ) 2 ](NO 3 ) 3 with (ox = oxalate, dien = diethylenetriamine) has been synthesized and charac- terized by single-crystal X-ray diffraction as well as FTIR and UV–Vis spectroscopic techniques. The complex crystallizes in the monoclinic space group (P2/c) with the following cell parameters ( ˚A, °): a = 23.7888(10), b = 6.7055(3), c = 12.7842(6) and β= 95.534(2). The 3D network consists of (C 2 O 4 ) groups bridging binuclear Cu(II) cations, in which the copper atoms are in a distorted square-pyramidal coordination environment. Experimental and computed FT-IR results confirmed the presence of charac- teristic bands of diethylenetriamine tridentate, nitrate and oxalate bidentate groups. UV–Vis spectrum of the complex was recorded and the characteristic transitions were determined. TG-DSC measurements re- vealed thermal stability of the studied complex until 473 K. Calcination of the complex under air led to the production of CuO nanoparticles. Moreover, the morphology and the size of the complex and its CuO nanoparticles were monitored by scanning electron microscopy (SEM). Magnetization and a.c. sus- ceptibility were measured and discussed. The complex molecular structure was optimized and the simu- lated geometric parameters compared with the crystal structure values. Hirshfeld surface and topological analyses were performed to describe the intermolecular interactions and to simplify the 3D networks of [Cu 2 (ox)(dien) 2 ](NO 3 ) 3 . Moreover, its antioxidant activity was assessed using DPPH, ferric reducing power tests and phosphomolybdenum assay.Öğe Synthesis, nanostructuring and in silico studies of a new imine bond containing a macroheterocycle as a promising PBP-2a non-b-lactam inhibitor(2023)This study is devoted to the synthesis of a 40-membered macroheterocycle with its further nanostructuring by magnetite nanoparticles. The mentioned macroheterocycle was synthesized by the [2+2] cyclocondensation of the oxygen-containing diamine with an aromatic dialdehyde in a noncatalytic medium and with no work-up procedure. The structure of the obtained macroheterocycle was studied by 1H and 13C nuclear magnetic resonance spectroscopy and matrix-assisted laser desorption/ ionization-time of flight mass spectrometry. Furthermore, the nanosupramolecular complex of macroheterocycles with magnetite nanoparticles was obtained and investigated by Fourier-transform infrared and ultraviolet-visible spectroscopy methods. Shifts in the infrared spectra of the nanosupramolecular complex indicate the interaction through metal-aromatic ring non-covalent bonding. The shift is also observed for the C–O–C stretching band of ether bonds. The loading rate of macroheterocycles on magnetite nanoparticles was 18.6%. The morphology of the ensemble was studied by transmission electron microscopy, which confirmed the synthesis of nanospherical particles with a diameter range of 10–20 nm. Powder X-ray diffraction analysis showed patterns of cubic Fe3O4 nanoparticles with a crystallite size equal to 9.1 nm. The macroheterocycle and its nanosupramolecular complex were tested against Klebsiella pneumoniae, Pseudomonas aeruginosa and Staphylococcus aureus. The results have shown that the created complex has shown 64 times better activity against Staphylococcus aureus in comparison with the individual macroheterocycle and 32 times better activity in comparison with the pristine antibiotic Ampicillin as a control. In addition, computational analysis of the macroheterocycle was performed at the B3LYP/6-31G level in water. Molecular docking analyses for the macroheterocycle revealed Penicillin-binding protein PBP2a (5M18) from the transpeptidase family as a target protein in Staphylococcus aureus.Öğe Improved carbon steel corrosion characteristics in static and hydrodynamic HCl media by two novel N2O2 ligands: Experimental and theoretical studies(2023)Background: Expanding the use of carbon steel in various industrial operations is always associated with challenges due to many engineering factors in the selection of materials. However, carbon-steel corrosion is a significant challenge in many industries, particularly the oil and gas sector. Methods: This study created and employed two novel N2O2 ligands to prevent simple carbon steel from corroding in static and dynamic hydrochloric acid solutions. Corrosion tests were performed in none, 50, 100, and 250 ppm of the new compounds. Therefore, immersion, potentiodynamic polarization (PDP), and electrochemical impedance spectroscopy (EIS) tests were used to investigate the anti-corrosion effect. In addition, the impact of hydrodynamic conditions on performing the inhibitors was also conducted. The B3LYP (Becke, 3-parameter, Lee–Yang–Parr), HF (Hartree–Fock), M062X approach with 6–31++G(d,p) basis sets was employed using the Gaussian software to study the inhibitory activities of molecules in the gas and water phases. Significant findings: According to the PDP test, there is a direct correlation between the amount of inhibitor and resistance to corrosion in static conditions, where the reduced ligand was more efficient. The EIS data revealed that, in a 1.0 M HCl solution with an inhibitor concentration of 250 ppm, the ligand and its reduced form enhanced corrosion resistance by 86.38% and 91.43%. Furthermore, these values were found to be 33.46% and 57.77%, in turbulent environment of 500 rpm. The atomic force microscopy (AFM) studies revealed that the ligand and its reduced form decreased surface roughness by 13.61% and 85.37% in static conditions and 59.67% and 61.53% in a hydrodynamic environment in comparison to 1.0 M HCl solution. Additionally, the UV test demonstrated that the amounts of iron corrosion was less severe in H2L2 than in H2L1 and 1.0 M HCl. Under static and dynamic conditions, the samples had lower specific weight changes during the immersion test, indicating that the inhibitory chemicals protected the samples’ surfaces. Both compounds followed the Langmuir adsorption process. Furthermore, quantum chemical parameters simulations indicate the compounds’ anticorrosive abilities.Öğe Crystal Structure, Hirshfeld Surface Analysis, In-Silico and Antimycotic Investigations of Methyl 6-methyl-4-(4- nitrophenyl)-2-oxo-1,2-dihydropyrimidine-5-carboxylate(2023)Herein, we report the preparation of methyl 6-methyl-4-(4-nitrophenyl)-2-oxo-1,2- dihydropyrimidine-5-carboxylate 2, obtained by the regioselective oxidative dehydrogenation of the dihydropyrimidine derivative 1 in the presence of cerium ammonium nitrate. The structure of compound 2 was investigated by single-crystal X-ray diffraction (SC-XRD), which allowed the determination of its tautomeric form. Moreover, the presence of non-covalent interactions and their impact on the crystal structure were analyzed. To better characterize the intermolecular contacts, the Hirshfeld surface and enrichment ratio analyses were performed. Furthermore, the antimycotic activity of compounds 1 and 2 was investigated against Candida albicans, Aspergillus flavus, and Aspergillus niger, and their efficacy was compared to that of fluconazole. Computational investigations on the putative target of the compounds provided insights to explain the better activity of 2 with respect to its synthetic precursor.
