Browsing by Author "Şener İ."

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A combined experimental and computational study of electrochemical and photophysical properties of new benzophenone derivatives functionalized with N-substituted-phenyl-1,3,4-thiadiazole-2-amine
(2020-03-05) Şener İ.; Şahin Ç.; Demir S.; Şener N.; Gür M.
New benzophenone derivatives with N-substituted-1,3,4-thiadiazole including different substituents were synthesized and characterized by using FTIR, NMR, UV/Visible, and fluorescence spectroscopies and cyclic voltammetry. The effect of –F, -Cl, –OCH3 and –NO2 substitutions at ortho-, meta-, para-positions on the photoluminescence properties of the molecules have been investigated. The results indicate that the electron-donating and electron-withdrawing moieties at the ortho-, meta-, and para-positions have an important effect on the photoluminescence properties of the molecules. The calculated the highest occupied molecular orbital (HOMO) and the lowest unoccupied molecular orbital (LUMO) energy levels are in the range of (−5.55) to (−5.65) eV and (−2.83) to (−3.02), respectively. The lower LUMO energy levels were observed for the molecules with –OCH3 substituents due to the donor strength of the substituent. Excited states and electrochemical properties of the molecules were also comprehensively and quantitatively studied by Density Functional Theory and Time-Dependent Density Functional Theory calculations. Experimental trends were successfully revealed by calculated data.
A combined experimental and DFT investigation of disazo dye having pyrazole skeleton
(2017-02-05) Şener N.; Bayrakdar A.; Kart H.; Şener İ.
Disazo dye containing pyrazole skeleton has been synthesized. The structure of the dye has been confirmed by using FT-IR, 1H NMR, 13C NMR, HRMS spectral technique and elemental analysis. The molecular geometry and infrared spectrum are also calculated by the Density Functional Theory (DFT) employing B3LYP level with 6-311G (d,p) basis set. The chemical shifts calculation for 1H NMR of the title molecule is done by using by Gauge-Invariant Atomic Orbital (GIAO) method by utilizing the same basis sets. The total density of state, the partial density of state and the overlap population density of state diagram analysis are done via Gauss Sum 3.0 program. Frontier molecular orbitals such as highest occupied molecular orbital (HOMO) and lowest unoccupied molecular orbital (LUMO) and molecular electrostatic potential surface on the title molecule are predicted for various intramolecular interactions that are responsible for the stabilization of the molecule. The experimental results and theoretical values have been compared.
Anticancer, antimicrobial, and DNA protection analysis of novel 2,4-dihydroxyquinoline dyes
(2018-10-01) Şener N.; Mohammed H.J.A.; Yerlikaya S.; Celik Altunoglu Y.; Gür M.; Baloglu M.C.; Şener İ.
A new series of 2,4-dihydroxyquinoline derived disazo dyes has been synthesized by the reaction of 5-amino-4-phenylazo-3-methyl-1H-pyrazole derivatives with 2,4-dihydroxyquinoline. The structures of the obtained dyes were identified by various spectrophotometric methods such as FT-IR, 1H-NMR, and elemental analysis. The synthesized compounds were also examined for different biological activities, including DNA protection, antimicrobial, and anticancer activities. Compound 3b was found most effective on Gram-positive bacteria. A DNA protection assay was applied to all compounds, and it was found that compounds 3h and 3j had a high capacity for binding to DNA. Besides, compounds 3h and 3j showed cytotoxicity against HeLa and PC3 cancer cell lines. These compounds could potentially be used as drugs or drug additives based on their effects on bacterial and cancer cell lines.
Antiproliferative properties and structural analysis of newly synthesized Schiff bases bearing pyrazole derivatives and molecular docking studies
(2021-10-05) Şener N.; Özkinali S.; Altunoglu Y.C.; Yerlikaya S.; Gökçe H.; Zurnaci M.; Gür M.; Baloglu M.C.; Şener İ.
New pyrazole Schiff bases containing azo groups were synthesized using the condensation reaction between p-nitrobenzaldehyde and (E)-4-(phenyl)-1-H-pyrazole-3,5-diamine in the molar ratio of 1:2. Characterization of the compounds was performed by spectroscopic techniques, including IR, UV-Vis, 1H-NMR and 13C-NMR. Biological activity of the compounds was evaluated by analyzing DNA protection, antimicrobial and anticancer properties. Compound 4 was effective for Salmonella typhimurium with the MIC concentration of 62.5 µg/mL. Moreover, this compound had the highest protection activity on DNA. Cytotoxic activity of compound 4 was determined on the HeLa cancer cell line with the IC50 concentration of 976.6 µM. The anti-cancer characteristic of compounds 4 and 5 for HeLa cancer was theoretically analyzed by molecular docking study as well. Among the tested compounds, compound 4 possessed significant results due to its in vitro cytotoxic properties. Therefore, it may be considered as a potential bioactive agent for cancer treatment studies. In addition, further in vivo analysis can be performed to indicate its anticancer property.
Antiproliferative-antimicrobial properties and structural analysis of newly synthesized Schiff bases derived from some 1,3,4-thiadiazole compounds
(2020-11-05) Gür M.; Yerlikaya S.; Şener N.; Özkınalı S.; Baloglu M.C.; Gökçe H.; Altunoglu Y.C.; Demir S.; Şener İ.
The 1,3,4-thiadiazole core has been mainly used as a pharmacological scaffold in medicinal chemistry. A series of Schiff bases derived from 5-substituted-1,3,4-thiadiazole-2-amine were designed and synthesized to investigate their biological activities. Structures of compounds were clarified with FTIR, 1H NMR and elemental analysis. Due to the importance of this core in pharmacology, all these newly synthesized compounds were tested for different biological properties at the same time. Compound 3A ((E)-N-(2,5-dimethoxybenzylidene)-5-(4-methoxyquinolin-2-yl)-1,3,4-thiadiazol-2-amine) and compound 4A ((E)-N-(2,5-dimethoxybenzylidene)-5-(3-methylbenzofuran-2-yl)-1,3,4-thiadiazol-2-amine) possessed high DNA protective ability against oxidative Fenton mixture. Compound 1A ((E)-N-(2,5-dimethoxybenzylidene)-5-(benzo[b]thiophen-2-yl)-1,3,4-thiadiazol-2-amine) and compound 2B ((E)-2-((5-(1H-indol-2-yl)-1,3,4-thiadiazol-2-ylimino)methyl)-6-methoxyphenol) showed strong antimicrobial activity against S. epidermidis. The most effective compound was detected as compound 3A which exhibited cytotoxicity on both PC-3 and MDA-MB-231 cancer cell lines. The IC50 of this compound was calculated as 370.7 μM and 505.1 μM for MDA-MB-231 and PC-3 cells, respectively. Molecular docking studies were also performed to examine the understanding of the mechanism behind the anti-cancer and anti-bacterial properties. For further study, compound 3A has the potential for utilization with chemotherapy drugs to establish a more efficient therapy strategy with minimum cytotoxicity against cancer cells.
New 1,3,4-thiadiazole compounds including pyrazine moiety: Synthesis, structural properties and antimicrobial features
(2017-07-05) Gür M.; Şener N.; Muğlu H.; Çavuş M.S.; Özkan O.E.; Kandemirli F.; Şener İ.
In the study, some new 1,3,4-thiadiazole compounds were synthesized and we have reported identification of the structures by using UV-Vis, FT-IR, 1H NMR, 13C NMR and Mass spectroscopic methods. Antimicrobial activities of the compounds against three microorganisms, namely, Candida albicans ATCC 26555, Staphylococcus aureus ATCC 9144, and Escherichia coli ATCC 25922 were investigated by using disk diffusion method. These thiadiazoles exhibited an antimicrobial activity against Staphylococcus aureus and Candida albicans. The experimental data was supported by the quantum chemical calculations. Density functional theory (DFT) calculations were carried out to obtain the ground state optimized geometries of the molecules using the B3LYP, M06 and PBE1PBE methods with 3–21 g, 4–31 g, 6–311++g(2d,2p), cc-pvtz and cc-pvqz basis sets in the different combinations. Frontier molecular orbitals (FMOs) energies, band gap energies and some chemical reactivity parameters were calculated by using the aforementioned methods and basis sets, and the results were also compared with the experimental UV-Vis data.
Novel Disubstituted Calix[4]arenes Containing Chromogenic Groups on the Lower Rim: Synthesis, Structural Identification, and Absorption Properties
(2018-04-01) Şener N.; Erişkin S.; Gür M.; Şener İ.
5,11,17,23-Tetra-tert-butyl-25,26,27,28-tetrahydroxycalix[4]arene and 25,26,27,28-tetrahydroxycalix[4]arene were synthesized based on previous literature. Firstly, several azo dyes were synthesized, and then, these dyestuffs were chlorinated through reaction with thionyl chloride. Secondly, the azo compounds bonded with methylene chloride and reacted with 25,26,27,28-tetrahydroxycalix[4]arene, and then, six novel disazocalix[4]arene derivatives 4(a–f) were achieved. Their structures were characterized as Fourier transform infrared, 1H-NMR, and elemental analysis. In this study, we investigated the solvatochromic properties of the compounds and the acid–base effect on their ultraviolet–visible absorption by using six solvents.
Organic fluorescent compounds based on phenanthroimidazole: A review of highlight studies
(2023-01-01) Zurnacı M.; Şener İ.; Gür M.; Şener N.
Strongly fluorescing silver(I) complex of a new thiadiazole ligand: X-ray crystallography, close anagostic interactions and TD-DFT emissive states
(2019-09-17) Demir S.; Gür M.; Şener N.; Şener İ.; Alpaslan G.
A new thiadiazole ligand, N-ethyl-5- (benzo[b]thien-2-yl-)-1,3,4-thiadiazol-2-amine (BTH), was prepared from 3-methyl-1-benzofuran-2-carboxylic acid and N-ethylhydrazinecarbothioamide precursors. Corresponding silver(I) complex, tetrakis(N-ethyl-5-(benzo[b]thien-2-yl-)-1,3,4-thiadiazol-2-amine)silver(I) nitrate [Ag2(BTH)4](NO3)2 (1), was prepared. The structures of BTH and 1 were characterized by 1H-NMR, 13C-NMR, FT-IR, elemental analysis and HR-MS techniques. Furthermore, molecular structure of 1 was illuminated by X-ray crystallography. Owing to strong anagsotic interaction, crystal structure of the complex revealed an intriguing asymmetric monomer unit even with two same ligands in 2:1 metal-to-ligand stoichiometry. Photoluminescence properties of the complex were investigated by solid and solution media emission measurements. Excited and emissive state behavior of the complex was further analyzed by quantum chemical TD-DFT calculations and natural transition orbital (NTO) analyses.
Studies on Antimicrobial, Antibiofilm, Efflux Pump Inhibiting, and ADMET Properties of Newly Synthesized 1,3,4-Thiadiazole Derivatives**
(2021-12-06) Zurnacı M.; Şenturan M.; Şener N.; Gür M.; Altınöz E.; Şener İ.; Altuner E.M.
The novel compounds bearing 1,3,4-thiadiazole moiety were obtained and their structures were identified using FT-IR, NMR methods, elemental, and mass analysis. UV-Vis and fluorescence spectra were obtained in six different polarity solvents. In addition, antimicrobial, antibiofilm, and the efflux pump inhibiting activities of the new compounds on K. pneumoniae, methicillin-resistant S. aureus (MRSA), E. coli, and C. albicans were investigated. Furthermore, druglikeness and ADMET properties of the compounds were determined. As a result, it was observed that some of the derivatives presented antimicrobial activity against K. pneumoniae, S. aureus, and C. albicans. But the MBC/MFC test showed that all the activities were bacteriostatic. In addition, these derivatives have the potential of using both inhibiting and activating biofilm formation depending on the concentration. 1,3,4-thiadiazole derivatives also presented good efflux pump inhibition in K. pneumoniae and E. coli. ADMET tests showed that 1,3,4-thiadiazole derivatives have the potential of being used as therapeutic compounds.
Study on Photophysical Properties of Novel Fluorescent Phenanthroimidazole-Thiadiazole Hybrid Derivatives
(2022-05-01) Zurnacı M.; Şener İ.; Gür M.; Şener N.
Phenanthroimidazole-thiadiazole hybrid derivatives, which are new heterocyclic compounds with fluorescence properties, were synthesized by designing a two-step reaction mechanism and their photophysical properties were investigated. The synthesized derivatives were purified and their structures were elucidated by ATR-IR, 1H-NMR, elemental analysis and HR-MS methods. In the next stage of the study, the absorption and emission spectra of the synthesized new phenanthroimidazole-thiadiazole hybrid derivatives were determined by UV–Vis and fluorescence spectroscopy. Stokes’ shifts, molar extinction coefficients (ε), singlet energy levels (Es), quantum yield (ϕf), lifetimes (τ), the radiative (kr) and the nonradiative (knr) constant for new hybrid derivatives were measured in DMSO. In addition, aggregation measurements, which is an important parameter that changes the photophysical properties were performed and for these compounds, structure: photophysical properties were discussed.
Synthesis and characterization of some new 1,3,4-thiadiazole compounds derived from 3,4-(Methylenedioxy)cinnamic acid and their antimicrobial activities
(2019-01-01) Muğlu H.; Gür M.; Hsin M.A.M.B.; Şener N.; Özkınalı S.; Özkan O.E.; Şener İ.
Some new 1,3,4-thiadiazole compounds derived from 3,4-(methylenedioxy)cinnamic acid were synthesized in this study. Their structures were determined using UV-Vis, IR,1H-NMR, and13C-NMR spectroscopy. Moreover, the antibacterial activities of the new 1,3,4-thiadiazole derivatives were tested against Gram positive (Enterococcus durans, Bacillus subtilis, and Staphylococcus aureus) and gram negative (Salmonella typhimurium, Escherichia coli, Salmonella enteritidis, Salmonella in-fantis, Salmonella kentucky, Enterobacter aerogenes) bacteria using the disk diffusion method. Furthermore, their antifungal activity was tested against Candida albicans using the disk diffusion method. Some of the synthesized compounds (V, VII, XIII, and XIV) showed antibacterial activity against S. aureus. Also, one synthesized compound (VIII) showed antibacterial activity against E. coli, exhibiting 8 and 9 mm inhibition zones using 50 and 80 µL. One compound (IX) showed antibacterial activity against E. aerogenes, exhibiting a 12 mm inhibition zone using 80 µL. One compound (XIII) showed antibacterial activity against S. kentucky, exhibiting an inhibition zone of about 9 mm using 80 µL. Also, one compound (VII) showed antibacterial activity against E. durans, exhibiting 7, 7, and 8 mm inhibition zones using 30, 50, and 80 µL. None of the compounds (I-XV) showed antifungal activity against C. albicans. These results showed that some of the synthesized compounds could be used as antibacterial agents.
Synthesis of a new 1,3,4-thiadiazole-substituted phenanthroimidazole derivative, its growth on glass/ITO as a thin film and analysis of some surface and optoelectronic properties
(2021-12-28) Zurnaci M.; Ünal F.; Demir S.; Gür M.; Şener N.; Şener İ.
A new phenanthroimidazole derivative (PMItz) bearing a 1,3,4-thiadiazole moiety was prepared and deposited as a thin film on a previously prepared glass/ITO substrate via the physical vapor deposition (PVD) method. The optical and surface morphological properties of the fabricated thin film, glass/ITO/PMItz, were investigated via UV-Vis spectroscopy, atomic force microscopy (AFM) and scanning electron microscopy (SEM). Subsequently, metal/ITO/PMItz/metal (metal: In and Ag) devices were fabricated and their electrical properties were investigated. The optical measurements revealed the reasonably high optical conductivities of the thin films. The energy band gap was calculated to be 2.96 eV, the absorption coefficient was calculated to be 1.3 × 106 m-1 and the optical conductivity was calculated to be 3.14 × 1014. The typical diode characteristics of the devices were demonstrated by electrical measurements. The current-voltage (I-V) measurements revealed that the devices exhibited photo-sensitivity, the photovoltaic effect and strong negative differential resistance (NDR) effect at certain voltage values. The ideality factors in the dark were calculated to be 2.4 and 2.54 for the In/ITO/PMItz/In and Ag/ITO/PMItz/Ag devices, respectively. According to the Hall effect measurements, the conductivity of PMItz was found to be p-type with high carrier mobility and concentration and low specific resistance. This journal is
Synthesis, Characterization, and Fluorescence Studies of Novel Heterocyclic Azo Dyes Derived from Benzothiazole
(2017-11-01) Şener N.; Erişkin S.; Şahin Ç.; Yılmaz M.; Şener İ.
Ten novel fluorescent azo disperse dyes 2a–e (open forms) and 3a–e (closed forms) were obtained by the coupling reaction of carbocyclic amine based diazonium chloride with compounds 2 and 3. The synthesized dyes were characterized by elemental analysis, high-resolution mass spectrometry, Fourier transform infrared, and NMR spectral techniques. Moreover, we investigated the substituent effect and solvatochromic properties of the dyes on absorption and fluorescence spectra. At the same time, the absorption and emission spectral data of the closed form dyes 3a–e were compared with the open form dyes 2a–e due to more planarity of the closed form dyes that lead to the extension of the π–electron conjugation.
Synthesis, Characterization, and Theoretical Calculation of New Azo Dyes Derived from [1,5-a]Pyrimidine-5-one Having Solvatochromic Properties
(2019-03-01) Şener N.; Gür M.; Çavuş M.S.; Zurnaci M.; Şener İ.
7-Amino-3-phenylazo-2-methyl-4H-pyrazolo[1,5-a]pyrimidine-5-one (3) was synthesized by the reaction of 5-amino-3-methyl-4-phenylazo-1H-pyrazole and 2-aminobenzothiazole with ethyl cyanoacetate in acetic acid at 150°C. Four novel heterocyclic azo disperse dyes were obtained by the coupling of heterocyclic amines-based diazonium chloride with compound 3. They were purified and characterized by elemental analysis, FTIR, and 1 H NMR. Furthermore, solvatochromic behaviors of related dyes were studied in detail by using ultraviolet–visible absorption spectrometer. The experimental data were supported by density functional theory using b3lyp/cc-pvtz level calculations, and a detailed analysis of predicted tautomeric structures was made.
Synthesis, Characterization, Solvatochromic Properties, and Antimicrobial-radical Scavenging Activities of New Diazo Dyes Derived from Pyrazolo[1,5-a]pyrimidine
(2017-11-01) Şener N.; Erişkin S.; Yavuz S.; Şener İ.
5-Amino-3-methyl-4-phenylazo-1H-pyrazole and ethyl cyanoacetate reacted in solvent-free media at 150°C to produce 7-amino-3-phenylazo-2-methyl-4H-pyrazolo[1,5-a]pyrimidine-5-one (3). A series of aromatic amines was coupled using this compound (3) and nitrous acid to produce new pyrazolo[1,5-a] pyrimidine derivatives with two arylazo groups 4(a-m). The structures of these dyes were determined via UV–vis, Fourier transform infrared, proton nuclear magnetic resonance, high-resolution mass spectral data, and elemental analysis. After synthesis, the solvent and acid–base effects of the dyes were investigated within the UV–vis region. The antimicrobial properties of the dyes were also studied. All dyes exhibited activity against Gram-positive and Gram-negative bacteria, and even against fungi. The results were compared to conventional reference results from the antibiotics ciprofloxacin and ketoconazole. Antioxidant potentials were analyzed using in vitro antioxidant models on the basis of DPPH (1,1-diphenyl-2-picrylhydrazyl) radical scavenging activities. Most of the compounds exhibited excellent antioxidant activities. In particular, compound 4b had a higher activity than Vitamin C.
Synthesis, structural analysis, and absorption properties of disperse benzothiazol-derivative mono-azo dyes
(2018-12-15) Şener İ.; Şener N.; Gür M.
A series of carbocyclic amines was reacted with 3-aminocrotonitrile to give the 2-arylhydrazone-3-ketiminobutyronitriles 1(a–m). Separately, 2-aminobenzothiazole was treated with hydrazine monohydrate to afford 2-hydrazinobenzothiazole. Then, compounds 1(a–m) were reacted with 2-hydrazinobenzimidazole under reflux in ethanol to give the 1-(1,3-benzothiazol-2-yl)-3-methyl-4-arylazo-5-aminopyrazole compounds 2(a–m). The structures of the synthesized compounds were investigated using FT-IR and 1H NMR spectroscopic methods and elemental analysis. Furthermore, the absorption profiles of the dyes in different solvents and in acidic and basic media were investigated.