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    Alkylation of morpholine and prolidine by phthalimide substituted Ru(II)- NHC catalysts
    (Pergamon-Elsevier Science Ltd, 2024) Akkoc, Mitat; Gurbuz, Nevin; Ozdemir, Ismail
    In this study, a series of benzimidazolium salts and silver-benimidazol-2-ylidene complexes were synthesized. The obtained silver complexes were converted into Ru(II)- benimidazol-2-ylidene complex using the transmetallation method. After elucidating the structures of these Ru(II)-NHC compounds, the synthesized ruthenium complexes were used in the alkylation reaction of cyclic amines to synthesize valuable derivatives such as pyrrolidine and morpholine. Pyrrolidine derivatives are extensively studied for their antimicrobial, antiviral, antifungal, anticancer, anti-inflammatory, anticonvulsant, cholinesterase inhibition, and carbonic anhydrase inhibition properties. Morpholine derivatives are particularly studied in the context of central nervous system (CNS) diseases. The yield of the catalytic products obtained was determined by GC. High selectivity and yield were achieved in the alkylation reactions of heterocyclic structures.
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    Benzimidazole-based N-heterocyclic carbene ruthenium(II) complexes: Synthesis and C-H bond activation properties
    (Elsevier, 2022) Akkoc, Mitat
    The transition-metal-promoted C-H activation has become an efficient as well as an atom-economic methodology for the synthesis of a wide array of organic molecules. Herein, the reaction of RuCl2(p-cymene)](2) with 1,3-dialkylbenzimidazolium salts ( 1a-c ) in the presence of a small excess of cesium carbonate yields chelated eta(6)-arene, eta(1)-carbene ruthenium complexes ( 2a-c ). All synthesized compounds were characterized by elemental analysis and NMR spectroscopy. The catalytic activity of [Cl2Ru(eta(6)-arene, eta(1)-carbene)] complexes ( 2a-c ) were evaluated in the direct arylation of 2-phenylpyridine and 1-phenylpyrazole with (hetero)aryl chlorides derivative. (C) 2022 Published by Elsevier B.V.
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    Cost-effective sodium-ion batteries using a Na0.67Mn0.9Ni0.1O2 cathode and lavender-flower-waste-derived hard carbon with a comparative presodiation approach
    (Elsevier, 2026) Dogan, Ebru; Moeez, Iqra; Whba, Rawdah; Ozcan, Sibel; Akkoc, Mitat; Altin, Emine; Altin, Serdar
    The development of cost-effective, high-performance sodium-ion batteries (SIBs) is essential for large-scale energy storage systems. In this study, low-cost SIBs are fabricated using P2-type Na0.67Mn0.9Ni0.1O2 as the cathode and hard carbon (HC) derived from lavender flower waste as the anode. The synthesis of both electrode materials from widely accessible precursors ensures scalability and environmental sustainability. To address the sodium deficiency of HC, three different presodiation strategies-electrochemical, chemical, and direct contact-are systematically investigated, and the electrochemical performances of the full cells are compared. This evaluation reveals significant variations in the initial capacity, capacity retention, Coulombic efficiency, and rate performance. Although the direct-contact method delivers the highest initial capacity, electrochemical presodiation delivers superior long-term cycling stability and enhanced energy density. This comprehensive comparison of the electrochemical performance emphasizes the vital role of presodiation in enhancing the full-cell efficiency, while highlighting the potential methods for developing cost-effective and sustainable SIBs.
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    Enhanced catalytic performance of silica-supported Pd-NHC complexes in Suzuki-Miyaura coupling reactions
    (Elsevier, 2025) Akkoc, Mitat; Koc, Hatice Kubra; Ozdemir, Ismail
    Since silica-supported catalysts are effective due to their rigid but porous structure, which lacks thermal and chemical stability and swelling properties, the characteristic structure of this heterogeneous catalyst we synthesized was elucidated using methods such as NMR, XRD, FTIR, SEM, DTA, and TGA. In this study, benzimidazolium salt was first synthesized and then converted into a Pd-NHC complex. The synthesized Pd-NHC complex was bonded to the SiO2 structure, and heterogeneous SiO2@NHC@Pd was synthesized. The Suzuki-Miyaura C-C coupling reaction of this SiO2@NHC@Pd catalyst was successfully carried out under mild conditions in the presence of green solvents.
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    Magnetite@MCM-41 nanoparticles as support material for Pd-N-heterocyclic carbene complex: A magnetically separable catalyst for Suzuki-Miyaura reaction
    (Wiley, 2021) Akkoc, Mitat; Bugday, Nesrin; Altin, Serdar; Yasar, Sedat
    The Magnetite@MCM-41@NHC@Pd catalyst was obtained with Pd metal bound to the NHC ligand anchored to the surface of Fe3O4@MCM-41. It was characterized by Fourier transform infrared (FTIR) spectroscopy, transmission electron microscopy (TEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), energy disperse X-ray analysis (EDX), thermogravimetric analysis (TGA), differential thermal analysis (DTA), and scanning electron microscopy (SEM). The amount of Pd in the Magnetite@MCM-41@NHC@Pd was measure by inductively coupled plasma-optical emission spectroscopy (ICP-OES) analysis. The catalytic activity of Magnetite@MCM-41@NHC@Pd heterogeneous catalyst done on Suzuki-Miyaura reactions of aryl halides with different substituted arylboronic acid derivatives. All coupling reactions afforded excellent yields and up to 408404 Turnover Frequency (TOF) h(-1) in the presence of 2 mg of Magnetite@MCM-41@NHC@Pd catalyst (0.0564 mmol g(-1), 0.01127 mmol% Pd) at room temperature in 2-propanol/H2O (1:2). Moreover, Magnetite@MCM-41@NHC@Pd catalyst was recover by applying the magnet and reused for another reaction. The catalyst showed excellent structural and chemical stability and reused ten times without a substantial loss in its catalytic performance.
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    Molecular docking and in vitro anticancer studies of silver(I)-N-heterocyclic carbene complexes
    (Cell Press, 2022) Akkoc, Mitat; Khan, Siraj; Yuce, Hande; Turkmen, Nese Basak; Yasar, Seyma; Yasar, Sedat; Ozdemir, Ismail
    A series of symmetric and unsymmetrical benzimidazolium-based N-heterocyclic carbene (NHC) precursors (1a-i) and their silver complexes (2a-i) have been synthesized. The Ag(I)-NHC complexes were characterized by H-1, C-13 {H-1} NMR, FTIR, LC/MS-QTOF, and elemental analysis. Anticancer and cytotoxic activity of all Ag(I)-NHC complexes were tested against healthy fibroblast cell line (L929), breast cancer cell line (MCF-7), and neuro-blastoma cell line (SH-SY5Y) by MTS [3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4sulfo-phenyl)-2H-tetrazolium] assay. The 2b, 2c, 2e, 2g, 2h, and 2i complexes showed higher cytotoxicity than cisplatin against SH-SY5Y and MCF-7 and lower cytotoxic activity against L929 cell lines. Because of their high cytotoxic activity against cancer cells and low cytotoxicity against healthy fibroblast cell lines, the 2b, 2c, 2e, 2g, 2h, and 2i are expected to be new lead compounds. In addition, molecular docking studies were performed to explore the binding interactions of silver complexes with the enzyme to explore new anticancer compounds. Furthermore, ADME properties of all complexes were predicted to explore lead-like characteristics and may be a potential drug candidate for cancer treatment.
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    Synthesis and biological evaluation of Au-NHC complexes
    (Wiley, 2022) Ekinci, Orhan; Akkoc, Mitat; Khan, Siraj; Yasar, Sedat; Gurses, Canbolat; Noma, Samir; Yilmaz, Ismet
    New seven Au-N-heterocyclic carbene (NHC) complexes have been synthesized via transmetalation from Ag-NHC complexes. NHC salts, Ag-NHC, and Au-NHC complexes were fully characterized by widely used spectroscopic techniques. The molecular and crystal structures of 3b and 3f Au-NHC complexes were clarified through the single-crystal X-ray diffraction method. According to X-ray diffraction analysis results, the coordination geometry around Au(I) atoms in the complexes are revealed to be almost linear with C-Au-Cl angle. Anticancer activity, DNA binding, xanthine oxidase (XO) inhibitory activity studies, and molecular docking studies were evaluated for all Au-NHC complexes to explore the binding mechanism at the active site. The IC50 value of Au-NHC complexes against human colorectal cancer (Caco-2) and breast cancer (MCF-7) cell lines was defined by MTT assay. The IC50 values for MCF-7 in the range of 5.2 +/- 2 to 152.4 +/- 1 mu M and Caco-2 5.2 +/- 1 to 152.7 +/- 2 mu M showed that 3a, 3b, 3c, 3d, and 3g have better anticancer activity than Cisplatin incredibly complex 3a against both cancer cell line. All Au-NHC complexes showed excellent antimicrobial activity against different bacteria and fungi. 3a was the complex that exhibited the best antimicrobial activity here as well. The XO inhibitory activity experimental results indicated that all gold complexes showed remarkable inhibition activity against XO compared to the generally used standard, allopurinol. The range of IC50 value was determined from 0.407 to 2.681 mu M. 3d complex showed the lowest IC50 value at 0.407 mu M. DNA binding experiments were performed using agarose gel electrophoresis to observe the ability of synthesized Au-NHC complexes to interact with the supercoiled pUC19 plasmid DNA. Molecular docking studies were performed to determine the binding mode of all active compounds against the XO enzyme, antibacterial, antifungal, and MCF-7 cell lines.
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    Systematic study on the catalytic performance of NHC-ligated silver(I) complexes
    (Elsevier Science Sa, 2026) Akkoc, Mitat; Onder, Belgin; Evren, Enes; Karaca, Emine Ozge; Gurbuz, Nevin; Ozdemir, Ismail
    This study reports the synthesis of novel N-heterocyclic carbene (NHC) ligated silver(I) complexes, which are gaining increasing attention as versatile catalysts in organic synthesis. The structural properties of the synthesized compounds were elucidated in detail using various spectroscopic and thermal analysis techniques, including FTIR, NMR spectroscopy, and melting point determination. These analyses confirmed the successful formation of the complexes and verified that they exhibited the expected molecular structures. The low cost and unique chemical properties of silver make it an attractive alternative to other transition metals. In this context, the catalytic potential of the synthesized Ag-NHC complexes was investigated in the A3 coupling reaction, a key method for the synthesis of propargylamines. The A3 reaction is a crucial step in the formation of nitrogencontaining compounds of significant importance in pharmaceutical and natural product chemistry. Experimental results demonstrated that the Ag-NHC complexes effectively catalyzed the reaction, leading to high yields. In conclusion, this research successfully achieved the synthesis and characterization of new Ag-NHC complexes. Following the acquisition of structural analysis data, their catalytic activity in the A3 coupling reaction was successfully investigated.