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Öğe 1-Amino-2-hydroxy-4-naphthalenesulfonic acid based Schiff bases or naphtho[1,2-d]oxazoles: Selective synthesis and photophysical properties(Pergamon-Elsevier Science Ltd, 2015) Atahan, Alparslan; Durmuş, SefaA series of Schiff base and naphtho[1,2-d]oxazole derivatives were selectively synthesized via condensation reaction of 1-amino-2-hydroxy-4-naphthalenesulfonic acid and benzaldehyde derivatives at same conditions. The synthesized compounds were then characterized by using (HNMR)-H-1,(CNMR)-C-13, FTIR spectroscopies and elemental analyses. It was seen that the Schiff bases generated in the presence of OH group at ortho position of benzaldehyde derivatives. However, the products were naphtho[1,2-d]oxazoles in other cases. Then, the synthesized compounds were photophysically investigated by UV absorption and fluorescence emission spectroscopies. As a result, these Schiff bases have shown long wavelength absorption (lambda(max): 386 nm) and emission (lambda(max): 429-437 nm) effect while synthesized naphtho[1,2-d]oxazole derivatives have a set of absorption (lambda(max): about 296, 308, 320 nm) and emission maxima (lambda(max): 378-395 nm) at lower wavelength. (C) 2015 Elsevier B.V. All rights reserved.Öğe Antimicrobial, Antiproliferative Effects and Docking Studies of Methoxy Group Enriched Coumarin-Chalcone Hybrids(John Wiley and Sons Inc, 2023) Badreddin Musatat, Ahmad; Kılıçcıoğlu, İlker; Kurman, Yener; Dülger, Görkem; Alpay, Merve; Yağcı, Ravza; Atahan, AlparslanMethoxy group enriched eight coumarin-chalcone hybrid derivatives were synthesized. Antimicrobial/ antiproliferative activities were tested against eight human pathogenic microorganisms and four cancer cell lines (AGS, HepG2, MCF-7 and PC-3), respectively. Antimicrobial results showed that most of the compounds were almost more active than used standard antibiotics. Cytotoxicity results showed that 2,3,4-trimethoxyphenyl and thiophene containing structures have promising antiproliferative effects against AGS gastric cell lines with ?5 ?g/ml IC50 values. At the same time, 2,4-dimethoxyphenyl bearing derivative exhibited the lowest IC50 values against HepG2 (?10 ?g/ml) and PC-3 (?5 ?g/ml) cell lines. Particularly, the cell viabilities of MCF-7 cell lines were remarkably inhibited by all the compounds with lower IC50 values. Therefore, molecular docking studies between hybrid ligands and quinone reductase-2 enzyme (regulates in MCF-7 cancer cells) were performed. The results demonstrated that all the derivatives can smoothly interact with interested enzyme in agreement with the experimental results. Finally, ADME parameters were studied to reveal drug-likeness potentials of the coumarin-chalcone hybrids. © 2023 Wiley-VHCA AG, Zurich, Switzerland.Öğe Employing of 2-Acetylpyridine Based Chalcone as Hg2+ Sensing Material: Experimental and Theoretical Examination(Düzce Üniversitesi, 2022) Musatat, Ahmad Badreddin; Atahan, Alparslan; Aksu, Mecit; Zengin, MustafaThis study reports the evaluation of 2-acetylpyridine based chalcone structure as a useful sensing material for Hg2+ ion detection by the means of UV-visible spectroscopy. In this context, firstly, the most common twenty metal ions were treated by the chalcone structure which was synthesized from 2-acetylpyridine and 4-diphenylaminobenzaldehyde according to the known procedures. As result, the studied chalcone compound exhibited good sensing activity towards Hg2+ ion in acetonitrile/water medium with significant red-shift phenomenon. In addition, some photophysical/electronic parameters of the chalcone and its Hg2+ complex were determined experimentally and theoretically. B3LYP, PBE0 methods and SVP, TVZP, and TVZPP basis sets were used for theoretical calculations in acetonitrile media. Finally, experimental results were explained and the proposed sensing mechanism was supported via density functional theory (DFT) outputs.Öğe Evaluation of new chalcone derivatives as polyphenol oxidase inhibitors(Pergamon-Elsevier Science Ltd, 2011) Sönmez, Fatih; Sevmezler, Sedat; Atahan, Alparslan; Ceylan, Mustafa; Demir, Dudu; Gencer, Nahit; Küçükislamoğlu, MustafaA newly series of 4-(phenylurenyl) chalcone (4a-j) and 4'-(phenylurenyl/thiourenyl)chalcone (9a-l) derivatives were synthesized and their inhibitory effects on the diphenolase activity of banana tyrosinase were evaluated. Tyrosinase has been purified from banana on an affinity gel comprised of Sepharose 4B-L-tyrosine-p-aminobenzoic acid. The result showed that 4a-j inhibited the PPO enzyme activity. Conversely, 9a-h and 9i-l showed activator effect on tyrosinase enzyme activity. (C) 2011 Elsevier Ltd. All rights reserved.Öğe Evaluation of novel thiophene branched polystyrene as insulator layer in organic electronic device(Elsevier Science Bv, 2019) Günaydın, Okan; Demir, Ahmet; Atahan, Alparslan; Yardım, Tayfun; Yücedağ, İbrahimA novel thiophene branched polystyrene copolymer (PS-Th) was successfully synthesized and well characterized. Two different Organic Field Effect Transistor (OFET) devices were fabricated by using this novel PS-Th material and polystyrene (PS) as insulator materials and main performance parameters of the devices such as mobility (mu(FET)), on/off ratio (I-on/off), and threshold voltage (V-Th) were compared. Consequently, our results indicated that PS-Th copolymer was efficiently working as dielectric material for OFETs. Moreover, mu(FET) significantly enhanced (approx. 3.7 times) compared to the PS based OFET device while V-Th and I-on/off were slightly increasing. This situation can be explained by well organized molecular arrangement at the dielectric-semiconductor interface via thiophene-thiophene interaction between semiconductor material Poly(3-hexylthiophene-2,5-diyl) (P3HT) and insulator material PS-Th chains. (C) 2019 Elsevier B.V. All rights reserved.Öğe Exciton Migration and Surface Trapping for a Photonic Crystal Displaying Charge-Recombination Fluorescence(Wiley-V C H Verlag Gmbh, 2016) Al-Aqar, Roza; Atahan, Alparslan; Benniston, Andrew C.; Perks, Thomas; Waddell, Paul G.; Harriman, AnthonyA compact donor-acceptor molecular dyad has been synthesized by attaching an N,N-dimethylamino fragment to a naphthalic anhydride residue. The dyad shows fluorescence from an intramolecular charge-transfer state (i.e., charge-recombination fluorescence) in solution, with the photo-physical properties being strongly dependent on the solvent polarity. Similar emission is seen for single crystals of the target compound, the molecules being aligned head-to-head, although time-resolved emission profiles display dual-exponential kinetics. A second polymorph with the head-to-tail alignment also gives rise to two lifetimes that differ somewhat from those of the first structure, which are assigned to bulk and surface-bound molecules. Growing the crystal in the presence of Rhodamine B localizes the dye around the surface. Excitation of the crystal is followed by sub-ps exciton migration along the aligned stacks, with occasional crossing to adjacent stacks and trapping at the surface. Rhodamine B present at very low levels acts as the acceptor for excitons entering the surface layer. Crystals embedded in a polyester resin form an artificial light-harvesting antenna able to sensitize an amorphous silicon solar cell.Öğe In vitro inhibition effect of some chalcones on erythrocyte carbonic anhydrase I and II(Taylor & Francis Ltd, 2013) Gençer, Nahit; Bilen, Çiğdem; Demir, Dudu; Atahan, Alparslan; Ceylan, Mustafa; Küçükislamoğlu, MustafaIn this study, 4'-(phenylurenyl/thiourenyl) chalcones (14-25) were prepared from 4'-(phenylurenyl/thiourenyl)acetophenones and benzaldehyde derivatives by Claisen-Schmidt condensation. In vitro inhibition effects of chalcone derivatives on purified carbonic anhydrase I and carbonic anhydrase II were investigated by using the CO2 hydration method of Maren. The result showed that all the synthesized compounds inhibited the CA isoenzymes activity. 18 and 19 were found to be most active (IC50 = 25.41 m M and 23.06 mu M) for hCA I, respectively. For hCA II, 24 is the most active compound (IC50 = 14.40 mu M).Öğe A Novel Polyaromatic Chalcone with Multiple Functional Groups: Synthetic, Photophysical, and Computational Elucidation(Taylor & Francis Ltd, 2021) Atahan, AlparslanThe title polyaromatic chalcone compound (PyMQ-chalcone) was sequentially synthesized via a three steps synthetic procedure and well characterized. Structural illumination was achieved by 1D and 2D NMR techniques, FTIR, LCMS/MS, and SEM. Photophysical investigations showed that the emission capacity remarkably increased by aggregation although target compound exhibited lower emission at solution state in common organic solvents. Furthermore, addition of some metal cations (such as Al3+ and Cr3+) slightly enhanced the emission in acetonitrile/water media in metal sensing studies. Lastly, density-functional theory studies were carried out by ORCA 4.2.0 software ((B3LYP; def2-TZVP basis set) to determine some electronic parameters such as HOMO-LUMO energy, total energy, dipol moment, and bond lengths, etc.Öğe Organic/inorganic interfaced field-effect transistor properties with a novel organic semiconducting material(Taylor & Francis Ltd, 2016) Demir, Ahmet; Atahan, Alparslan; Bağcı, Sadık; Aslan, Metin; Islam, M. SaifA novel 1,3,4-oxadiazole-substituted benzo[b]triphenylene was synthesized by three-step synthetic procedure and OFET device design was successfully designed after theoretical calculations made using Gaussian software. For investigating the field-effect properties of designed organic electronic device, a SiO2 (300nm) was thermally grown on p-Si wafer at 1000 degrees C as a dielectric layer and gate, source and drain contacts have been deposited using Au metal with physical vapour deposition. 1,3,4-Oxadiazole-substituted benzo[b]triphenylene was spin coated on the source and drain electrodes of our device, forming organic/inorganic interfaced field-effect transistors. Surface morphology and thin film properties were investigated using AFM. All electrical measurements were done in air ambient. The device showed a typical p-type channel behaviour with increasing negative gate bias voltage values. Our results have surprisingly shown that the saturation regime of this device has high mobility (mu(FET)), excellent on/off ratio (I-on/I-off), high transconductance (g(m)) and a small threshold voltage (V-Th). The values of mu(FET), I-on/I-off, g(m) and V-Th were found as 5.02cm(2)/Vs, 0.7x10(3), 5.64 mu S/mm and 1.37V, respectively. These values show that our novel organic material could be a potential candidate for organic electronic device applications in the future.Öğe The Photophysical Properties of Triisopropylsilyl-ethynylpentacene-A Molecule with an Unusually Large Singlet-Triplet Energy Gap-In Solution and Solid Phases(Mdpi, 2020) Schaberle, Fabio A.; Serpa, Carlos; Arnaut, Luis G.; Ward, Andrew D.; Karlsson, Joshua K. G.; Atahan, Alparslan; Harriman, AnthonyThe process of singlet-exciton fission (SEF) has attracted much attention of late. One of the most popular SEF compounds is TIPS-pentacene (TIPS-P, where TIPS = triisopropylsilylethynyl) but, despite its extensive use as both a reference and building block, its photophysical properties are not so well established. In particular, the triplet state excitation energy remains uncertain. Here, we report quantitative data and spectral characterization for excited-singlet and -triplet states in dilute solution. The triplet energy is determined to be 7940 +/- 1200 cm(-1) on the basis of sensitization studies using time-resolved photoacoustic calorimetry. The triplet quantum yield at the limit of low concentration and low laser intensity is only ca. 1%. Self-quenching occurs at high solute concentration where the fluorescence yield and lifetime decrease markedly relative to dilute solution but we were unable to detect excimer emission by steady-state spectroscopy. Short-lived fluorescence, free from excimer emission or phosphorescence, occurs for crystals of TIPS-P, most likely from amorphous domains.Öğe Photophysics, pH sensing, and hydrolysis study of a novel 1,8-naphthalimide derivative(Turkish Chemical Society, 2018) Atahan, Alparslan; Orhan, ErsinIn this study, a novel highly emissive compound was synthesized via a two-step synthetic procedure and characterized by1H-NMR,13C-NMR and FTIR. Then its photophysical properties, pH sensing behaviors and pH-dependent hydrolysis were systematically investigated by ultraviolet and fluorescence spectroscopy. Photophysics studies were carried out in fourteen common organic solvents and absorption/emission spectra were recorded in Britton Robinson buffers (pH=3-12) to determine pH sensing behaviors. From the photophysical results, it has been shown that the novel compound exhibits strongly solvent polarity dependent emission and has high quantum yield (up to 0.72). Furthermore, at pH=12, absorbance started to decrease while emission was increasing and blue-shifting due to basic hydrolysis after a several minutes. Therefore, time dependent hydrolysis was also investigated at mentioned pH. © 2018, Turkish Chemical Society. All rights reserved.Öğe Pulse Radiolysis of TIPS-Pentacene and a Fluorene-bridged Bis(pentacene): Evidence for Intramolecular Singlet-Exciton Fission(Amer Chemical Soc, 2018) Karlsson, Joshua K. G.; Atahan, Alparslan; Harriman, Anthony; Tojo, Sachiko; Fujitsuka, Mamoru; Majima, TetsuroExposing TIPS-pentacene in deaerated benzene to ionizing radiation generates a mixture of singlet- and triplet-excited states of the solute. The singlet undergoes radiative decay without spin conversion whereas the triplet undergoes radiationless decay on the microsecond time scale. The concentration of each species was established by dosimetry. The excited-singlet state is not observed on the nanosecond-time scale for a related fluorene-bridged bis(pentacene), but the triplet is present in high concentration. Failure to detect the excited-singlet state is attributed to fast intramolecular singlet-exciton fission (iSEF) which is found to produce two triplet species. A short-lived intermediate (tau(T) = 145 ns) is identified as the species (T_T) having both pentacene units present as triplet states. The second transient is longer lived (tau(T) = 7.5 mu s) and is assigned to the corresponding species (T_G) with a single pentacene promoted to the triplet level. Dosimetry is used to conclude that iSEF partitions overwhelmingly in favor of T_G (70%) relative to T_T (25%). The total triplet yield from iSEF, therefore, is ca. 120% in this system, where the pentacene terminals are weakly coupled.Öğe Siringaldehit Bazlı Yeni 2,4,6-Triarilpiridin Türevlerinin Antioksidan Aktiviteleri ve Teorik Profili(Duzce University, 2024) Albayrak, Esra Nur; Şimşek, Samed; Musatat, Ahmad Badreddin; Akşit, Zeynep; Akşit, Hüseyin; Atahan, AlparslanSiringaldehitten türetilen sekiz adet yeni 2,4,6-triarilpiridin tasarlandı ve tek basamaklı multi-komponent yöntemle sentezlendi. Bu bileşiklerin antioksidan aktiviteleri bilinen referans bileşiklerle kıyaslanarak değerlendirildi. Daha sonra, B3LYP teorisi ve SVP, TVZP temel setleri kullanılarak, sentezlenen bileşikler için kapsamlı bir teorik kuantum hesaplama yaklaşımı oluşturuldu ve radikal yakalama potansiyelini tanımlayan Fukui indeksleri adlı elektronik yapı tanımlayıcı parametreler belirlendi. Son olarak, teorik ve deneysel sonuçlar karşılaştırılarak yapı-etkinlik ilişkisi ortaya konuldu. Sonuç olarak, elde edilen bileşiklerin antioksidan aktivite potansiyeli teorik bir yaklaşımla da desteklendi.Öğe Synthesis and Characterisation of Polyaromatic Chalcones with Electron Donation(2020) Atahan, AlparslanIn this study, a series of chalcone derivatives was successfully synthesized via condensation of 1- acetylpyrene with dimethylamine, diphenylamine or carbazole containing benzaldehyde derivatives at basic conditions. Spectral characterisations were acquired by 1 and 2 dimensional NMR techniques and FTIR. In addition, UV-vis and thermal analysis studies were performed to determine their absorption properties and thermal behaviours, respectively. Lastly, surface and film generation properties were investigated by the means of SEM images on ITO glass to determine usability potential in organic electronics.Keywords: Chalcone, Pyrene, Triphenylamine, Carbazole, Characterisation.Öğe Synthesis, Biological Activity and Structure-Activity Relationship of Novel Diphenylurea Derivatives Containing Tetrahydroquinoline as Carbonic Anhydrase I and II Inhibitors(Wiley-V C H Verlag Gmbh, 2018) Atahan, Alparslan; Gençer, Nahit; Bilen, Çiğdem; Yavuz, Emre; Genç, Hayriye; Sönmez, Fatih; Küçükislamoğlu, MustafaA series of novel tetrahydroquinoline derivatives containing urea moiety was synthesized and their invitro inhibitory effects on the human carbonic anhydrase isoenzymes (hCA-I and hCA-II) were evaluated by using the CO2 hydration method. All the synthesized compounds exhibited inhibitory activity against both hCA I and hCA II with 1-(4-fluorophenyl)-3-(4-(4-p-tolyl-5,6,7,8-tetrahydroquinolin-2-yl)phenyl)urea (7k, IC50 value of 5.28M and 5.51M, against hCA I and hCA II, respectively) as the strongest inhibitor in this study. Structure-activity relationships were also investigated. The results showed that most of synthesized compounds have a higher inhibitory activity against hCA I than hCA II. Also the substituents, containing two or more pairs of non-bonding electrons, generally increased the hCA I and II inhibitory activity. Furthermore, some electronic parameters such as the highest occupied molecular orbital and the lowest unoccupied molecular orbital (HOMO-LUMO) energy levels, electron affinity, total energy and dipole moments of the best inhibitors (7b, 7h and 7k) in this study were also calculated by using Gaussian software. The results revealed that HOMO-LUMO energy differences, total energy, chemical hardness and dipole moment of 7b, 7h and 7k showed a linear relationship with increasing inhibitory activity.Öğe Synthesis, characterization and electrochemical behavior of some Ni(II), Cu(II), Co(II) and Cd(II) complexes of ONS type tridentate Schiff base ligand(Pergamon-Elsevier Science Ltd, 2011) Durmuş, Sefa; Atahan, Alparslan; Zengin, MustafaTridentate Schiff base (H2L) ligand was synthesized via condensation of o-hydroxybenzaldehyde and 2-aminothiophenol. The metal complexes were prepared from reaction of the ligand with corresponding metal salts presence of substituted pyridine in two different solvents (MeOH or MeCN). The ligand and metal complexes were then characterized by using FTIR, TGA, H-1 NMR and C-13 NMR spectroscopies. The FTIR spectra showed that H2L was coordinated to the metal ions in tridentate manner with ONS donor sites of the azomethine N, deprotonated phenolic-OH and phenolic-SH. Furthermore, substituted pyridine was coordinated to the central metal atoms. The thermal behavior of the complexes was investigated by using TGA method and dissociations indicated that substituted pyridine and ligand were leaved from coordination. This coordination of the metal complexes was correlated by H-1 NMR and C-13 NMR. Finally, electrochemical behavior of the ligand and a Ni(II) complex were investigated. (C) 2011 Elsevier B.V. All rights reserved.Öğe Synthesis, enzyme inhibition, and molecular docking studies of a novel chalcone series bearing benzothiazole scaffold(Wiley, 2023) Musatat, Ahmad Badreddin; Atahan, Alparslan; Ergün, Adem; Çıkrıkçı, Kübra; Gençer, Nahit; Arslan, Oktay; Zengin, MustafaThis study reports the facile synthesis of a novel series of benzothiazole-chalcones, in addition to their inhibitory profile on important metabolic enzymes including human carbonic anhydrases (hCA-I, hCA-II) and paraoxonase (PON-1). The inhibition parameters, IC50 (concentration for 50% inhibition) and Ki (dissociation constant) values, toward the title enzymes were determined for the studied compounds. As a result, IC50 values of hydratase activity were in the range 4.15-5.47 and 2.56-4.58 mu M for hCA-I and hCA-II, respectively. At the same time, IC50 values of esterase activity were in the range 24.91-104.00 and 35.25-97.00 mu M, while Ki values were in the range 14.43-59.66 and 26.65-73.34 mu M for hCA-I and hCA-II, respectively. In addition, PON-1 enzyme inhibition results showed interesting inhibitory effects, with IC50 values between 13.28 and 16.68 mu M. Finally, a comprehensive approach was established for the synthesized compounds based on theoretical calculations, which have been done using B3LYP, PBE0 theories and SVP, TVZP, TVZPP basis sets, followed by docking studies by which the outputs proved the harmonically flows with the experimental results.
