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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 Design, Synthesis, and Chemical Characterization of Pyrene-Substituted BODIPY Dyes(Wiley-V C H Verlag Gmbh, 2025) Koksoy, BaybarsIn this study, novel di- and tetra-pyrenylated BODIPY (boron-dipyrromethene) dyes (Bdpy2 and Bdpy4) were synthesized via the Suzuki-Miyaura cross-coupling reaction, incorporating pyrene units at specific positions on the BODIPY core. Comprehensive structural characterization was achieved through FT-IR, UV-Vis, MALDI-mass spectrometry, and NMR techniques. The optical properties were extensively analyzed in different solvents, revealing Q-band absorption maxima at 531 nm for Bdpy2 and 533 nm for Bdpy4 in THF, along with red-shifted emission peaks due to increased pi-pi stacking interactions. Bdpy4 displayed a fluorescence quantum yield of 0.68 and a fluorescence lifetime of 3.88 ns, surpassing Bdpy2 ' s values of 0.61 and 3.44 ns, respectively. These improved values in Bdpy4 highlight the enhanced energy transfer efficiency provided by the additional pyrene groups. Theoretical TD-DFT calculations supported the experimental findings, indicating effective energy transfer from pyrene to the BODIPY core. These findings suggest that the high fluorescence efficiency and extended lifetimes of pyrenylated BODIPY derivatives make them promising candidates for optoelectronic applications, including bioimaging and energy harvesting.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 Effective ?-glycosidase inhibitors based on polyphenolic benzothiazole heterocycles(Academic Press Inc Elsevier Science, 2024) Sevimli, Esra; Seyhan, Gokce; Akkaya, Didem; Sari, Suat; Barut, Burak; Koksoy, Baybarsalpha-Glycosidase inhibition is one of the main approaches to treat Diabetes mellitus. Polyphenolic moieties are known to be responsible for yielding exhibit potent alpha-glycosidase inhibitory effects. In addition, compounds containing benzothiazole and Schiff base functionalities were previously reported to show alpha-glycosidase inhibition. In this paper, the synthesis of seven new phloroglucinol-containing benzothiazole Schiff base derivatives through the reaction of 6-substituted-2-aminobenzothiazole compounds with 2,4,6-trihydroxybenzaldehyde using acetic acid as a catalyst was reported. The synthesized compounds were characterized using spectroscopic methods such as FT-IR, 1 H NMR, 13 C NMR, and elemental analysis. The synthesized compounds were evaluated for their inhibitory effects on alpha-glycosidase, compounds 3f and 3g were found to show significant inhibitory properties when compared to the positive control. The IC 50 values of 3f and 3g were calculated as 24.05 +/- 2.28 and 18.51 +/- 1.19 mu M, respectively. Kinetic studies revealed that compounds 3f and 3g exhibited uncompetitive mode of inhibition against alpha-glycosidase. Molecular modeling predicted druglikeness for the title compounds and underpinned the importance of phloroglucinol hydroxyls for interacting with the key residues of alpha-glycosidase.Öğe ?-Glycosidase activity of novel coumarin-triazole-coumarin dyads(Tubitak Scientific & Technological Research Council Turkey, 2025) Sirin, Ersin; Sevimli, Esra; Seyhan, Gokce; Barut, Burak; Kaya, Yunus; Koksoy, BaybarsNovel coumarin-triazole-coumarin dyads were synthesized and characterized, and their alpha-glycosidase inhibitory activities were evaluated spectrophotometrically. Compound 4e exhibited the most pronounced inhibitory effect, with an IC50value of 38.98 +/- 0.77 mu M. The IC50 values for 4d and 4a were 93.55 +/- 1.70 mu M and 95.04 +/- 3.55 mu M, respectively. The Lineweaver-Burk plot showed that 4e inhibited alpha-glycosidase in a mixed type. In addition, the Ki value obtained from the Dixon plot was 19.95 +/- 0.15 mu M for alpha-glycosidase.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 Photophysicochemical and electrochemical properties of pyrene-BODIPY platforms(Royal Soc Chemistry, 2024) Omeroglu, Ipek; Koksoy, Baybars; Ozturk, Dilek; Salah, Lubna; Maksheed, Saad; Durmus, MahmutThe photochemical, photophysical, and electrochemical properties of BODIPY compounds (1-7) substituted with iodine or pyrene at the 2-, 6-, or 8-positions (meso) were thoroughly investigated in this study. Through the incorporation of iodine and/or pyrene moieties into the BODIPY derivatives, we evaluated their impact on the photophysical properties using both steady-state and time-resolved fluorescence analyses. Notably, the heavy atom effect induced by iodine was observed, leading to an increase in singlet oxygen quantum yield in proportion to fluorescence intensity. Furthermore, the introduction of pyrene at the meso position in BODIPY (compound 5) significantly enhanced the pi-conjugated system and facilitated the generation of singlet oxygen. Intriguingly, compound 7, which featured pyrene substitutions at positions 2, 6, and 8, exhibited a reduced singlet oxygen yield when compared to the iodine-substituted compound 6. Moreover, we conducted an evaluation of the electrochemical properties of the BODIPY compounds (1-7) in dichloromethane. Additionally, we characterized the structures of the synthesized compounds (5 diamond , 6, and 7) using various spectroscopic techniques, including FT-IR, HRMS, and NMR (1H, 13C, 19F, and 11B), which were performed for the first time within the scope of this study. The comprehensive findings obtained from this extensive research contribute valuable knowledge that has the potential to guide the development of highly efficacious photosensitizers for applications in photodynamic therapy. The photochemical, photophysical, and electrochemical properties of novel BODIPY compounds substituted with iodine or pyrene groups at the 2-, 6-, or 8-positions (meso) were thoroughly investigated.
