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Öğe A New Strategy for Photo-Electrochemical Reduction of Carbon Dioxide Using a Carbazole-BODIPY Based Metal-Free Catalyst(Wiley-V C H Verlag Gmbh, 2025) Ozdemir, Mucahit; Ulucay, Sude; Altinisik, Sinem; Koksoy, Baybars; Yalcin, Bahattin; Koyuncu, SermetIn this study, a cross-linked boron dipyrromethene (BODIPY) photocatalyst containing a carbazole donor group designed for photoelectrocatalytic carbon dioxide (CO2) reduction is synthesized and characterized. The BODIPY-based system, coated onto a platinum surface, is evaluated for its electrochemical and photocatalytic performance under light illumination. Cyclic voltammetry (CV) and chronoamperometry measurements reveals enhanced photocurrent responses, confirming the catalyst's ability to effectively drive CO2 reduction. Gas chromatography/mass spectrometry (GC-MS) analysis identifies the formation of ethanol (C2H5OH) as a major reaction product, showing that its yield increased with extended reaction times. Additionally, the photocatalyst demonstrates remarkable performance with significantly increasing turnover numbers (TON) and turnover frequencies (TOF) over time, indicating stable and sustained catalytic activity. With a Faradaic efficiency of 34.79% at a potential of -1.15 V, this BODIPY system exhibits both high activity and long-term stability. The combination of efficient electron transfer and visible light absorption by the carbazole-BODIPY donor-acceptor structure positions this system as a highly promising candidate for sustainable CO2 conversion applications.Öğe DNA and hemoglobin binding activities: Investigation of coumarin-thiosemicarbazone hybrids(Academic Press Inc Elsevier Science, 2024) Celik, Esra; Meletli, Furkan; Ozdemir, Mucahit; Koksoy, Baybars; Danis, Ozkan; Yalcin, BahattinCoumarin and coumarin-thiosemicarbazone hybrids were synthesized and characterized by various techniques such as FT-IR, 1H NMR, 13C NMR, MALDI-TOF-MS spectroscopy, and single crystal X-Ray diffractometer (XRD). The photochemical and photophysical properties of the compounds, such as solvatochromism, solubility, and chemical reactivity, were analyzed using UV-vis spectroscopy in different solvents. Due to the potential biological activities of the synthesized compounds, their binding affinity and mechanisms with calf thymus DNA (ctDNA) and bovine hemoglobin (BHb) were determined using several useful spectrophotometric and theoretical approaches such as UV-vis absorption and fluorescence spectroscopy, molecular docking, and density functional theory (DFT). The experimental results showed that the compounds exhibited strong binding interactions with DNA and BHb. Additionally, the compounds demonstrated predominantly binding modes, such as intercalation and groove binding with DNA and pi-pi stacking interactions with BHb. To better understand the thermodynamics of these interactions, quenching constants, binding constants, and Gibbs free energy changes (Delta G degrees) were calculated. Molecular docking and DFT results supported the experimental data regarding the binding affinity and mechanisms of the compounds to DNA and BHb. Overall, this comprehensive study on coumarin and coumarin-thiosemicarbazone hybrids provides valuable insights into their interaction mechanisms with critical biomolecules, highlighting their potential in therapeutic applications as multifunctional agents.Öğe Heavy Atom-Enhanced Photooxidation Performance of Carbazole-Substituted BODIPY Dyes(Wiley-V C H Verlag Gmbh, 2025) Ozdemir, Mucahit; Sevimli, Esra; Ozan, Gulsema; Salan, Umit; Yalcin, Bahattin; Koksoy, BaybarsIn this study, halogenated BODIPYs (C-Br-2-BDPY and C-I-2-BDPY) bearing a carbazole group at the meso position are synthesized and characterized using various spectroscopic techniques. Single-crystal X-ray diffraction analysis of the C-I-2-BDPY revealed that it crystallizes in a triclinic crystal system with a P-1 space group. The optical properties, singlet oxygen generation capacities, and photocatalytic activities of the BODIPY derivatives are evaluated with respect to juglone synthesis. While the nonhalogenated BODIPY (C-BDPY) exhibit negligible singlet oxygen generation (Phi(Delta) < 0.05), the iodinated (C-I-2-BDPY) and brominated (C-Br-2-BDPY) derivatives demonstrate considerably higher singlet oxygen quantum yields of 0.82 and 0.73, respectively. In the photooxidation reaction of 1,5-dihydroxynaphthalene (DHN) to juglone, these halogenated BODIPY compounds achieve conversion yields of 62.6% for C-Br-2-BDPY and 87.8% for C-I-2-BDPY within one hour. The turnover number values of the BODIPY photosensitizers show a continuous increase over time, indicating sustained product formation, whereas the turnover frequency values gradually decline, reflecting the decrease in reaction rate as the process progress. Density functional theory calculations support the experimental results by demonstrating that the presence of heavy atoms facilitates intersystem crossing and enhances the thermodynamic feasibility of the photooxidation reactions.Öğe Investigating the Photochemical Properties of a Clickable Silicon (IV) Phthalocyanine Core(Wiley-V C H Verlag Gmbh, 2025) Ozdemir, Mucahit; Sevimli, Esra; Ozturkkan, Fureya Elif; Durmus, Mahmut; Yalcin, Bahattin; Koksoy, BaybarsIn this study, a new azido-functionalized silicon(IV) phthalocyanine (SiPcN3) was synthesized and comprehensively characterized, revealing its promising photochemical characteristics. Despite the common challenges associated with crystallizing phthalocyanine-based compounds, SiPcN3 was successfully obtained as single crystals in the monoclinic P21/c space group. The incorporation of -N3 groups not only enhanced the compound's solubility and thermal stability but also introduced a reactive site suitable for future functionalization via copper-catalyzed azide-alkyne click chemistry. The molecular design enables straightforward integration into extended macromolecular systems, such as covalent organic frameworks (COFs) or cross-linked polymers. UV-Vis and photoluminescence analyses demonstrated intense Q-band absorption in the red region and tunable emission characteristics. The measured singlet oxygen quantum yield (Phi Delta = 0.14) indicates moderate photosensitizing activity, but this performance can potentially be enhanced through appropriate derivatization, improving its applicability in photodynamic therapy (PDT). Overall, these findings position SiPcN3 as a structurally versatile and functionally adaptable molecular platform, with promising potential for future development of PDT agents, photocatalytic/photooxidative materials, and optoelectronic devices, especially when embedded into porous or cross-linked polymeric networks.Öğe Light driven photocatalytic hydrogen generation using BODIPY-thiophene-covalent organic polymers(Pergamon-Elsevier Science Ltd, 2025) Turgut, Ki bra; Ozdemir, Mucahit; Yildiz, Gizem; Yalcin, Bahattin; Koyuncu, Sermet; Koksoy, Baybars; Patir, Imren HatayBoron-dipyrromethene (BODIPY)-based dyes have recently garnered attention as sensitizers for photocatalytic hydrogen production. They exhibit high catalytic activity through efficient electron transfer, owing to their unique properties such as high molar absorptivity, adjustable absorption and emission energies, and high fluorescence quantum efficiencies. In this study, the effect of a-OH subunit that can increase hydrophilicity on the photocatalytic hydrogen evolution in BODIPY-thiophene-based covalent organic polymers (COP) was investigated. In the conducted research, COP structures were integrated into BODIPY to enhance their light absorption capabilities, aiming to serve as photocatalysts for energy conversions under simple conditions. In the proposed system, Thiophene-BODIPY-based dyes are integrated into COP structures, where they facilitate electron excitation upon light absorption, thereby playing an effective role in photocatalytic reactions by promoting electron transfer. The photocatalyst, modified with titanium dioxide (TiO2) nanoparticles, exhibited notable performance in enhancing the efficiency of the hydrogen production process, owing to its light absorption capabilities, multifunctional fluorescent properties, and electron-accepting characteristics. The synthesized BODIPY-Th-COP-OH_TiO2 photocatalyst demonstrated higher hydrogen activity compared to BODIPY-Th-COP-CH3_TiO2, attributed to the presence of hydroxyl groups promoted hydrophilic character in the catalyst structure. Therefore, BODIPY-Th-COP-X_TiO2 photocatalysts (X: OH, CH3) utilizing methanol as sacrificial agent yielded hydrogen amounts of 0.197 mmol g-1 h-1 and 0.132 mmol g-1 h-1 for BODIPY-Th-COP-OH_TiO2 and BODIPY-Th-COP-CH3_TiO2 photocatalysts, respectively, under visible light illumination.Öğe Light-Induced Performance Enhancement of Supercapacitors through Thiol-Ene Click Surface Functionalization of Thienothiophene-BODIPY Porous Polymers(Amer Chemical Soc, 2025) Ozdemir, Mucahit; Ulucay, Sude; Sevimli, Esra; Altinisik, Sinem; Koksoy, Baybars; Yalcin, Bahattin; Koyuncu, SermetPhotoassisted supercapacitors are emerging as next-generation energy storage devices that synergistically combine light harvesting and electrochemical energy storage. BODIPY-based semiconductors, known for their strong light absorption, tunable electronic properties, and photostability, have recently attracted attention as efficient photoactive components in such systems. This study investigates the potential use of cross-linked thieno[3,2-b]thiophene-BODIPY polymer as an electrode material for photoassisted supercapacitors, prepared through a surface functionalization approach using thiol-ene click chemistry. The polymer exhibited broad-band absorption and a low band gap due to extended conjugation, as confirmed by UV-vis and fluorescence spectroscopy, along with comprehensive optical, electrochemical, and morphological characterization. DFT calculations showed that the HOMO-LUMO energy gap narrows under illumination, indicating improved charge transport. Cyclic voltammetry (CV), galvanostatic charge-discharge (GCD), and electrochemical impedance spectroscopy (EIS) measurements confirmed that the cross-linked polymer offers high capacitance, low internal resistance, and long cycle stability. In terms of supercapacitor performance, a photoinduced enhancement of up to 50% in specific capacitance was observed under light. At a current density of 1.0 A/g, the specific capacitance increased from 240 F/g in the dark to 362 F/g under illumination. Stability tests conducted over 2000 cycles demonstrated that the supercapacitor retained 90% of its initial capacitance.Öğe Başlıksız(Taylor & Francis Inc, 2022) Ozdemir, Mucahit; Köksoy, Baybars; Ceyhan, Deniz; Sayin, Koray; Ercag, Erol; Bulut, MustafaThe novel coronavirus (SARS-CoV-2) causes severe acute respiratory syndrome and can be fatal. In particular, antiviral drugs that are currently available to treat infection in the respiratory tract have been experienced, but there is a need for new antiviral drugs that are targeted and inhibit coronavirus. The antiviral properties of organic compounds found in nature, especially coumarins, are known and widely studied. Coumarins, which are also metabolites in many medicinal drugs, should be investigated as inhibitors against coronavirus due to their pharmacophore properties (low toxicity and high pharmacokinetic properties). The easy addition of substituents to the chemical structures of coumarins makes these structures unique for the drug design. This study focuses on factors that increase the molecular binding and antiviral properties of coumarins. Molecular docking studies have been carried out to five different proteins (Spike S1-subunit, NSP5, NSP12, NSP15, and NSP16) of the SARS-CoV-2 and two proteins (ACE2 and VKORC1) of human. The best binding scores for 17 coumarins were determined for NSP12 (NonStructural Protein-12). The highest score (-10.01 kcal/mol) in the coumarin group is 2-morpholinoethan-1-amine substituted coumarin. Molecular mechanics Poisson-Boltzmann surface area (MM-PBSA) analyses of selected ligand-protein complexes were performed. The binding energies in each 5 ns were calculated and it was found that the interaction between ligand and target protein were stable. Communicated by Ramaswamy H. Sarma
