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    Nickel (II) complex [NiCl2(DMF)2L2] bearing diaminobenzene and sulfonamide: Crystal structure and catalytic application in the reduction of nitrobenzenes
    (Pergamon-Elsevier Science Ltd, 2020) Dayan, Serkan; Kayaci, Nilgun; Dayan, Osman; Ozdemir, Namik; Ozpozan, Nilgun Kalaycioglu
    A new Bis[N-(2-aminophenyl)benzenesulfonamidej-di-chloro-Bis[O'-N,N-dimethyl-formamide]-nickel (II) complex [NiCl2(DMF)(2)L2] was synthesized in DMF solution in reflux media with NiCl2.2H(2)O and the pre-prepared N-(2-aminophenyl)benzenesulfonamide and the [NiCl2(DMF)(2)L-2] complex was crystallized in DMF/diethyl ether solution, for its single crystal. The complex characterized by FT-IR, elemental analysis, TG-DTA and UV Vis spectrophotometry methods, and its single crystal study were also performed by X-ray spectroscopy. Additionally, the catalytic efficiency of the fabricated [NiCl2(DMF)(2)L-2] complex was determined by UV Vis spectrophotometry in the reduction reaction of 2-nitroaniline (2-NA), 4-nitroaniline (4-NA) and nitrobenzene (NB) in presence of NaBH4 in water. The best conversion obtained as a result of the reduction of nitroarenes in the short time of 10 min. was 62.5 %, which was obtained at the 2-NA reduction. The conversion obtained from of the reduction of nitroarenes, are sequenced as 2-NA (62.5 %) > NB (56.5 %) > 4-NA (25.5%) in 10 min. In addition, the reaction products, both aqueous and short-term, are harmless to the environment, which will provide a significant reaction variety in terms of green chemistry. (C) 2019 Elsevier Ltd. All rights reserved.
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    One-pot stepwise reductive amination reaction by N-coordinate sulfonamido-functionalized Ru(II) complexes in water
    (Wiley, 2018) Kayaci, Nilgun; Dayan, Serkan; Ozdemir, Namik; Dayan, Osman; Ozpozan, Nilgun Kalaycioglu
    New complexes of formula [RuCl(p-cymene)(L)] (7-12) were prepared with [RuCl2(p-cymene)](2) and pre-synthesized N-arenesulfonly-o-phenylenediamines (1-6) and characterized using H-1 NMR, C-13 NMR, Fourier transform infrared and UV-visible spectroscopic techniques, and single-crystal X-ray diffraction analysis was performed for one complex (8). Complexes 7-12 were investigated in the reduced imine synthesis reaction (in the presence of HCOONa/HCOOH). The best turnover frequency values were found to be 100 h(-1) for 1 and 99 h(-1) for 6 in the transfer hydrogenative reductive amination reaction of 4-methoxyaniline and 3,4,5-trimethoxybenzaldehyde. The most important feature of this reaction is that it is an environmental friendly procedure because of being conducted in an aqueous environment. That no organic solvent is used allows one to say that this reaction represents green chemistry.
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    Palladium(II) complexes assembled on solid materials: as catalysts for the -NO2 (nitro) to -NH2 (amine) reactions
    (Springer Wien, 2020) Dayan, Serkan; Kayaci, Nilgun; Ozdemir, Namik; Dayan, Osman; Kalaycioglu Ozpozan, Nilgun
    Herein, a new series of [PdCl2(L)(2)] complexes where ligands are monodentate amine ligands bearing sulfonamide groups were synthesized, characterized using various techniques such as NMR, FT-IR, UV-Vis, and sc-XRD and investigated for their catalytic performance for the reduction of nitroarenes (2-nitroaniline, 4-nitroaniline, and nitrobenzene) in the presence of NaBH4 in water under heterogeneous conditions. Because the results show that the synthesized complexes are very efficient catalysts, materials using the selected palladium(II) complex supported by multiwall carbon nanotubes, silicon dioxide, and iron(II,III) oxide (Fe3O4) were fabricated by a simple-impregnation methodology, characterized by FT-IR, BET, TEM, and XRD techniques and investigated for their catalytic performance for the same reaction. Thus, a series of supported catalysts was designed with the aim of both enhancing catalytic activity and reducing noble-metal contents. Our findings serve to develop simple catalytic systems and this system can be easily used for catalytic reduction reactions which are the cornerstone of the production of important chemicals. [GRAPHICS] .
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    SBA-15-supported N-coordinate ruthenium(II) materials bearing sulfonamide-type ligands: Effect of ligand backbones on catalytic transfer hydrogenation of ketones and aldehydes
    (Wiley, 2017) Dayan, Serkan; Kayaci, Nilgun; Ozpozan, Nilgun Kalaycioglu; Dayan, Osman
    [RuLCl(p-cymene)] (L=N-arylsulfonylphenylenediamine) complexes (2(a-d)) were synthesized from the reaction between [Ru(p-cymene)Cl-2](2) and ligand. Additionally, SBA-15-[RuLCl(p-cymene)] derived catalysts (3(a-d)) were successfully immobilized onto mesoporous silica (SBA-15) by an easily accessible approach. The structural elucidations of 2(a-d) and 3(a-d) were carried out with various methods such as H-1 NMR, C-13 NMR and infrared spectroscopies, elemental analysis, thermogravimetric/differential thermal analysis, nitrogen adsorption-desorption and scanning electron microscopy/energy-dispersive X-ray analysis. The Ru(II) complexes and materials were found to be highly active and selective catalysts for the transfer hydrogenation (TH) reaction of aldehydes and ketones. The influence of various 1,2-phenylenediamines on the reactivity of the catalysts (complexes or materials) was studied and the catalysts (2(d) and 3(d)) with a 4,5-dichlorophenylenediamine substituent showed the best activity (the maximum turnover frequencies are 2916 and 2154h(-1) for TH of 4-fluoroacetophenone, and 6000 and 4956h(-1) for TH of 4-chlorobenzaldehyde).
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    Synthesis of ruthenium(II) complexes derived from reduced imine ligands: As catalysts for transfer hydrogenation of ketones
    (Elsevier Science Sa, 2013) Dayan, Serkan; Kayaci, Nilgun; Kalaycioglu, Nilgun Ozpozan; Dayan, Osman; Ozturk, Esra Circir
    N-[2-(benzylamino)phenyl]benzenesulfonamide derivatives (1-6) were successfully synthesized by the reaction of imine ligands derived from various N-(2-aminophenyl)benzenesulfonamides and NaBH4. Then, a series of N-coordinate Ru(II) arene complexes 7-12 were prepared from the reaction of [RuCl2(p-cymene)](2) with 1-6. The synthesized compounds were characterized by different methods such as NMR, FT-IR, and elemental analysis. 7-12 were used as catalysts for the transfer hydrogenation (TH) of ketones. At the same time, the effect of various bases such as NaOH, KOH, KOBut and Et3N as organic base were investigated in TH of ketones by 2-propanol as the hydrogen source. 7-12 showed good catalytic activity and so the effects of the different groups were also examined. Crown Copyright (c) 2013 Published by Elsevier B.V. All rights reserved.