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Öğe Synthesis and characterization of oligo(phenoxy-imine)s of Schiff bases containing phenyl-1,3,5-triazine unit: limit oxygen index values of oligomers(Springer, 2024) Kaya, İsmet; Cicigül, Melike; Yağmur, Hatice KaraerAromatic compounds containing hydroxyl groups in their structure are converted to oligomer or polymer products from the combination of phenoxy-structured radical units in the presence of oxidants such as O2, H2O2 and NaOCl in alkaline or acidic aqueous media. These macromolecule compounds are used in many fields in industry because they contain both phenyl units and different functional groups in their structures. Since the phenyl units in the main chain give rigidity to the structure, the thermal stabilities of these types of polymers are quite good. Schiff base compounds were obtained as a result of the condensation reaction of 4-hydroxy-3-methoxybenzaldehyde, 2-hydroxybenzaldehyde, 4-hydroxybenzaldehyde, 5-bromsalicylaldehyde and 2-hydroxy-1-naphthaldehyde compounds with 2,4-diamino-6-phenyl-1,3,5-triazine as amine. Oligo(phenoxy-imine)s were synthesized from Schiff bases by oxidative polycondensation in the presence of O2 oxidant in aqueous alkaline medium. The structural characterizations of Schiff bases and oligo(phenoxy-imine)s were performed by FT-IR, 1H-NMR, 13C-NMR and UV-Vis analyses. Electrochemical band gap (Eg '\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$E<^>{\prime}_{g}$$\end{document}) values of monomers and oligomers were calculated from CV measurements. The Eg '\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$E<^>{\prime}_{g}$$\end{document} values of FMD, FMB, FMM, FMF, FMN, OFMD, P-FMB, OFMM, OFMF and OFMN were calculated to be 2.80, 2.63, 2.52, 2.76, 2.12, 2.57, 2.49, 2.44, 2.51 and 2.07 eV, respectively. Limit oxygen index values of OFMD, P-FMB, OFMM, OFMF and OFMN were calculated to be 33.46%, 38.85%, 38.43%, 44.86% and 23.46%, respectively. Also, the molecular weight distributions, glass transition temperature (Tg) and surface images of oligomers were determined from GPC, DSC and SEM measurements, respectively.Öğe Enhancing aseptic inflammation resolution with 1-(2-Ethoxyethyl)-4-(pent-1-yn-1-yl)piperidin-4-yl propionate: A novel β-Cyclodextrin complex as a therapeutic agent(Multidisciplinary Digital Publishing Institute (MDPI), 2024) Zhumakova, Symbat; Tokusheva, Aliya; Zharkynbek, Tolganay; Balabekova, Marina; Kõks, Sulev; Seilkhanov, Tulegen; Dembitsky, Valery; Aydemir, MuratThe synthesized compound, 1-(2-ethoxyethyl)-4-(pent-1-yn-1-yl)piperidin-4-yl propionate (EPPP), and its 1:1 complex with β-cyclodextrin (EPPPβCD) have been characterized for the first time through a comprehensive suite of analytical methods. This study explores the therapeutic potential of EPPPβCD in modulating immune responses and accelerating the resolution of septic inflammation induced by chromium and vanadium ions in outbred male rats. The research highlights the significant impact of EPPPβCD on the dynamics of regulatory T lymphocytes (Tregs), notably causing a reduction in the CD4+CD25+ fractions at the onset of inflammation. This effect is attributed to the inhibition of Treg proliferation, which is crucial in hastening the resolution of inflammation. These findings underscore the potential of EPPPβCD as a promising therapeutic agent in controlling and mitigating inflammation mediated by heavy metal exposure, thereby offering a new avenue for the development of anti-inflammatory treatments.Öğe Integrated catalytic and energy storage performance of grass waste derived Ni-Based catalyst(Springer Nature, 2024) Karakaş, Duygu Elma; Horoz, Sabit; Durap, Feyyaz; Orak, Ceren; Kaya, MustafaThis study focuses on the optimization and characterization of a grass waste-derived catalyst, GW-Ni-Cat, for hydrogen generation via NaBH4 methanolysis, as well as its application in supercapacitors. Optimization experiments were conducted to determine the optimal conditions for acid concentration, metal concentration, carbonization temperature, and carbonization time. The catalyst was characterized using various techniques including FTIR, XRD, SEM, TEM, BET, and ICP-OES. Performance experiments demonstrated the catalyst's efficiency in hydrogen generation, with key factors such as catalyst amount, NaBH4 concentration, and temperature influencing the reaction kinetics. Reusability tests showed the catalyst's stability over multiple cycles. Electrochemical characterization revealed the suitability of GW-Ni-Cat as an electrode material for supercapacitors, with high specific capacitance values. Comparison with other bio-based supercapacitors demonstrated the superior performance of GW-Ni-Cat. Overall, this study presents GW-Ni-Cat as a versatile and efficient material for both hydrogen generation and energy storage applications.Öğe Benzothiazole-based poly(phenoxy-imine)s containing ethoxy and methoxy units: synthesis, thermal and optical properties(Springer Science and Business Media Deutschland GmbH, 2024) Kaya, İsmet; Dinçer, Emin; Yağmur, Hatice KaraerSchiff bases (S1 and S2) were synthesized from the condensation reaction of 2-amino-6-ethoxybenzothiazole with 3-hydroxy-4-methoxybenzaldehyde and 3-hydroxy-4-ethoxybenzaldehyde. P-S1-A and P-S2-A poly(phenoxy-imine)s, and P-S1-O and P-S2-O poly(phenoxy-imine)s were synthesized through oxidative polycondensation (P) of S1 and S2 by NaOCl oxidant in alkaline (A) solution (10% KOH aquation solution) and by H2O2 (35% aquation solution) in THF organic (O) medium, respectively. The structures of the Schiff bases and poly(phenoxy-imine)s were characterized by FTIR, NMR, UV–Vis and TG/DTA investigations. The limit oxygen index (LOI) and heat-resistance index temperature (THRI) values were determined from thermogravimetric analysis data of compounds. The LOI values of poly(phenoxy-imine)s were between 21.16 and 33.87. The molecular weight distributions and glass transition temperatures of poly(phenoxy-imine)s were determined from gel permeation chromatography (GPC) and DSC, respectively. The Mn values of P-S1-O, P-S1-A, P-S2-O and P-S2-A were found to be 5800, 15500, 5600 and 9400 Da, respectively. Moreover, the polymerization degree (DP) values of P-S1-O, P-S1-A, P-S2-O and P-S2-A were calculated to be 18, 16, 47 and 28, respectively. The glass transition temperature (Tg) of P-S1-O, P-S1-A, S2, P-S2-O and P-S2-A were calculated from DSC curves at 115, 111, 102 and 128 °C, respectively. The surface images of poly(phenoxy-imine)s were determined with SEM analysis. The optical bandgap values of Schiff bases and poly(phenoxy-imine)s were calculated from UV–Vis measurements. The optical bandgap value of P-S2-A was calculated to be 1.95 eV. Graphical abstract: (Figure presented.)Öğe Deep eutectic solvents for sustainable management of asphaltene deposition in oil production(Engineered Science Publisher, 2024) Ryspaeva, Salimat; Kerimkulova, Aygul; Rafikova, Khadichakhan; Nauryzova, Saule; Islam, Sholpan; Aydemir, Murat; Kozhaisakova, MadinaDeep Eutectic Solvents (DES) offer a sustainable solution to mitigating asphaltene deposition in oil production, minimizing environmental impact and enhancing the operational efficiency in the petroleum industry. The paper investigates the sustainable management of asphaltene deposition in oil production through the application of Deep Eutectic Solvents (DESs). Three DES formulations were prepared: DES1 (Citric acid:Glycerin, 1:4 ratio), DES2 (Citric acid:Ethylene Glycol, 1:4 ratio), and DES3 (Choline chloride:Glycerin, 1:2 ratio). The physical properties (pH, density, and viscosity) of these DESs were measured. The study utilized Karazhanbas crude oil from Western Kazakhstan, characterized by distinct hydrocarbon groups. The weight composition was as follows: Paraffin-naphthenic 17.2%, Aromatic (light) 10.2%, Aromatic (medium) 8.1%, Aromatic (heavy) 28.2%, Total resins 24.1%, and Asphaltenes 12.2%. The FTIR spectrum of the received DES and asphaltene was also determined. Asphaltene deposition was studied both with and without DES inhibitors. Microscopic tests revealed that DES3 exhibited superior results, as evidenced by significantly smaller asphaltene particle sizes compared to other DES formulations and the control without DES. The findings suggest that DES3 holds promise as an effective inhibitor for asphaltene deposition in oil production, offering a sustainable and environmentally friendly approach to address challenges associated with asphaltene-related issues in the petroleum industry.Öğe Determination of zinc in dried nuts by slotted quartz tube-flame atomic absorption spectrometry (SQT-FAAS) with citric acid-coated magnetic nanoparticle (CAMNP) based solid phase extraction (SPE)(Taylor and Francis Ltd., 2024) Umaz, Kader; Umaz, Adil; Aydın, Işıl; Aydın, FıratThis study reports a sensitive method for trace zinc using slotted quartz tube-flame atomic absorption spectrometry (SQT-FAAS) with citric acid-coated magnetic nanoparticle-solid phase extraction (CAMNP-SPE). To increase the efficiency, we univariately optimized the pH, buffer volume, CAMNP mass, eluent concentration and volume, mixing type and time, temperature, and interaction time. The study identified the limits of detection and quantification values for CAMNP-SPE-SQT-FAAS under the specified optimum conditions to be 12.30 and 41.00 μg L−1, respectively. The newly developed method improved the detection power of traditional FAAS by 13.25 times. The findings of this study report a sensitive and accurate method to determine trace zinc in complex matrices.Öğe Well designed iridium-phosphinite complexes: Biological assays, electrochemical behavior and density functional theory calculations(Elsevier B.V., 2024) Khadichakhan Rafikova; Meriç, Nermin; Binbay, Nil Ertekin; Okumuş, Veysi; Erdem, Kemal; Belyankova, Yelizaveta; Güzel, RemziyeMononuclear phosphinite Iridium complexes based on ferrocene group have been prepared and characterized by various spectroscopic techniques. The complexes were subjected to cyclic voltammetry studies in order to determine the energies of HOMO and LUMO levels and to estimate their electrochemical and some electronic properties. Organic complex-based memory substrates were immobilized using TiO2-modified ITO electrodes, and the memory functions of phosphinite-based organic complexes were verified by chronoamperometry (CA) and open-circuit potential amperometry (OCPA). Extensive theoretical and experimental investigations were directed to gain a more profound understanding of the chemical descriptors and the diverse electronic transitions taking place within the iridium complexes, as well as their electrochemical characteristics. The quantum chemical calculations were carried out for the iridium complexes at the DFT/CAM-B3LYP level of theory in the gas phase. Furthermore, the antioxidant, antimicrobial, DNA binding, and DNA cleavage activities of the complexes were tested. Complex 2 exhibited the highest radical scavenging activity (67.5 ± 2.24 %) at 200.0 mg/L concentration. It was observed that the complexes formed an inhibition zone in the range of 8–15 mm against Gram + bacteria and in the range of 0–13 mm against Gram – bacteria. The agarose gel electrophoresis method was used to determine the DNA binding and DNA cleavage activities of the complexes. All of the tested complexes had DNA binding activity; however, complexes 1, 2, and 8 showed better binding activity than the others.Öğe Application of phthalocyanine complexes of Cu(II), Co(II), Ni(II), and Zn(II) as catalysts in the transfer hydrogenation of acetophenone and its derivatives(Elsevier Ltd., 2024) Namlı, Mesut; Işık, Uğur; Kantar, Cihan; Aydemir, MuratIn this study, tetra substituted metallophthalocyanines (M: Ni, Zn, Co, and Cu) containing imine and azo groups were synthesized using microwave irradiation. The structures of all complexes have been totally characterized via 1HNMR, 13CNMR, TGA/DTA, LC-MS/MS, elemental analysis, UV–Vis, FT-IR spectroscopy. The comparison of the catalytic features of phthalocyanine based on metals is also discussed briefly. These phthalocyanine-complexes were also used in the transfer hydrogenation (TH) of acetophenone derivatives in the existence of KOH, utilizing isoPrOH as a hydrogen source. Acetophenone compounds determined a TH of up to 99 % conversion. Copper phthalocyanines were first used as catalysts in transfer hydrogenation reactions. The Cu(II) complexes showed higher catalytic activity, converting up to 97 % at 1.0 mol% catalyst loading. Furthermore, we have discovered that the catalytic characteristics of this class of molecules are significantly influenced by both steric and electronic variables.Öğe A sensitive determination of Brilliant Blue FCF in some food samples using hydrophillic deep eutectic solvent-assisted magnetic nano gel-based dispersive solid phase microextraction prior to spectrophotometric analysis(Elsevier Ltd, 2024) Erek, Figen; Lanjwani, Muhammad Farooque; Tüzen, MustafaA new magnetic nano gel (MNG) was prepared from choline chloride/phenol deep eutectic solvent and magnetic amberlite XAD-7 nanocomposite. The dispersive solid phase micro extraction (dSPME) method was developed for seperation and preconcentration of Brilliant Blue FCF (BB) by the prepared MNG. In this study, firstly, the optimum DES type and mole ratio of DES were investigated before response surface methodology optimization. Then, the effect of the MNG-dSPME experimental parameters were optimized by response surface methodology using central composite design. Under the optimum microextraction conditions, limit of detection (LOD), limit of quantification (LOQ), preconcentration factor (PF), enhencament factor (EF) were found to be 1.15 μg L−1,3.80 µg L-1, 70, and 88, respectively. It was seen that the recovery of real samples were obtained from 95.5 to 103.6%. The pesent method was succesfully for extraction of BB in some food, personal care samples, to the best of our knowledge, this is the first study that is presented method on determination of BB by preconcentration with magnetic nano gel. The obtained results showed that the present procedure is effective, sensitive, and has high accuracy for the quantitative detection of BB.Öğe Electrochemical evaluation of nivolumab used in cancer treatment with differential pulse voltammetry: A novel approach with single-use pencil graphite electrode(Springer Int Publ Ag, 2023) Aslan, Mehmet; Aydın, Fırat; Levent, AbdulkadirObjectivesNivolumab is used in a treatment called immunotherapy, which helps the immune system cells to attack cancer cells. The electrochemical properties and quantification of this drug were performed using single-use pencil tips.Evidence acquisitionHere, a selective voltammetric method for the determination and electrochemical characterization of Nivolumab used in cancer therapy was developed for the first time using a disposable pencil electrode by cyclic voltammetry and differential pulse voltammetry techniques. Nivolumab exhibited an anodic signal at +0.879 V (vs. Ag/AgCl) in PBS (pH 3.0, 0.02 M NaCl) medium.ResultsThis procedure showed a linear response in phosphate buffer solutions (pH 3.0, 0.02 M NaCl) media within the concentration range of 0.01 mg mL-1 to 0.07 mg mL-1 and limit of detection and the limit of quantification values were determined to be 2.49 mu g mL-1 and 8.30 mu g mL-1, respectively.ConclusionsThe developed method offers an important analytical approach for the detection and characterization of NIVO. Precisely measuring and monitoring the levels of such drugs in real sample analyses or biological samples is critical for evaluating response to treatment, optimizing treatment strategies. Therefore, the method was applied to real sample analyses. Voltammetric results developed using PG electrode were compared with UV-Vis results. It has been determined that the results obtained are compatible with each other.Öğe Some aromatic derivatives of 1,4,7,10,13,16-hexaoxacyclooctadecane(Springer Verlag, 1981) Hoşgören, Halil; Erk, Çakıl[Abstract Not Available]Öğe Application of half-sandwich metal-phosphinite compounds to biological activities: Determine the energies of the HOMO and LUMO levels(Wiley-V C H Verlag Gmbh, 2023) Meriç, Nermin; Rafikova, Khadichakhan; Zazybin, Alexey; Güzel, Remziye; Kayan, Cezmi; Karakas, Duygu Elma; Dündar, Abdurrahman; Aydemir, MuratMononuclear transition metal complexes 1-(furan-2-yl)ethyldiphenyl[dichloro(eta(6)-p-cymene)ruthenium(II)]phosphinite, (2), 1-(furan-2-yl)ethyldiphenyl[dichloro(eta(6)-benzene) ruthenium(II)] phosphinite (3), 1-(furan-2-yl)ethyldipheny[chloro(eta(4)-1,5-cyclooctadiene)rhodium(I)]phosphinite (4), 1-(furan-2-yl)ethyldiphenyl[dichloro (eta(5)pentamethylcyclopentadienyl)iridium (III)] phosphinite (5) were synthesized and characterized by microanalysis, infrared, MS, and NMR spectroscopy. The biological activities of the complexes were also tested. Compounds 2 and 5 were the best complexes at DPPH radical scavenging and reducing power activity at 73.27 % and 0.41 at 200 mu g/mL, respectively. The highest antimicrobial activity exhibited by complex 3 as 14 mm inhibition zone against S. aureus. All of the complexes have cleaved the DNA from the double-strand and exhibited three bands on gel electrophoresis. Moreover, cyclic voltammetry studies of the phosphinite complexes were carried out to determine the energies of the HOMO and LUMO levels as well as to estimate their electrochemical and some electronic properties.Öğe Immobilization of ?-amylase via adsorption onto bentonite/chitosan composite: Determination of equilibrium, kinetics and thermodynamic parameters(Wiley-V C H Verlag Gmbh, 2014) Baysal, Zübeyde; Bulut, Yasemin; Yavuz, Murat; Aytekin, ÇetinImmobilization of -amylase onto bentonite/chitosan (BC) composite was studied via adsorption. The composite was characterized by FTIR, SEM, and surface area measurements. The effect of different factors such as, pH, temperature, initial enzyme concentration, and various thermodynamic parameters was determined. The maximum -amylase adsorption capacity of the BC composite was determined as 64mg/g at 0.8mg/mL enzyme concentration. The activity of the immobilized enzyme was measured under varying experimental conditions. The highest enzyme activity for free and immobilized enzyme was determined at 30 and 35 degrees C in 0.1M phosphate buffer at pH 7.0. The effect of substrate concentration on enzyme activity of free and immobilized enzymes showed a good fit to the Lineweaver-Burk plots. Michaelis constant, K-m, for the immobilized -amylase was found to be higher than for the free enzyme. The adsorption isotherm was modeled by the Langmuir equation.Öğe Effects of dietary boron on cervical cytopathology and on micronucleus frequency in exfoliated buccal cells(Wiley, 2007) Korkmaz, Mehmet; Uzgören, Engin; Bakirdere, Sezgin; Aydın, Fırat; Ataman, O. YavuzRecent evidence indicates that boron and borates may have anticarcinogenic properties. In this study, we have investigated the incidence of adverse cytological findings in cervical smears and the micronucleus (MN) frequency in women living in boron-rich and boron-poor regions. Cervical smears were prepared from 1059 women with low socioeconomic status; 472 of the women lived in relatively boron-rich rural areas, while 587 lived in relatively boron-poor regions. The average and standard deviation values for the age of the women screened with the cervical Pap smear test were 41.55 +/- 8.38. The mean dietary intake of boron was 8.41 mg/day for women from the boron-rich regions, and 1.26 mg/day for women living in the boron-poor regions (P < 0.0001). Women from the boron-rich regions had no cytopathological indications of cervical cancer, while there were cytopathological findings for 15 women from the boron-poor areas (chi(2) = - 10.473, P < 0.05). Sixty women, 30 from each region, were chosen for evaluating MN frequencies in exfoliated buccal cells. MN frequencies for women from the boron-rich and boron-poor regions were not significantly different (t = -0.294, P > 0.05). Also, there were no significant correlations between age and MN frequency for women from both the boron-rich (r = 0.133, P = 0.48, P > 0.05) and boron-poor (r = -0.033, P = 0.861, P > 0.05) regions. The results suggest that ingestion of boron in the drinking water decreases the incidence of cervical cancer-related histopathological findings. There was no correlation between the pathological findings from the cervical smears and buccal cell MN frequency suggesting that the two study populations were exposed equally to gentotoxic agents. Nonetheless, cervical cancer-related histopathological findings should be validated by other researchers. (c) 2007 Wiley Periodicals, Inc.Öğe Palladium nanoparticles supported on hydroxyapatite nanospheres: Highly active, reusable and green catalyst for Suzuki - Miyaura cross coupling reactions under aerobic conditions(Wiley-V C H Verlag Gmbh, 2018) Bulut, Ahmet; Aydemir, Murat; Durap, Feyyaz; Gülcan, Mehmet; Zahmakiran, MehmetThe development of simply prepared, highly active and reusable nanocatalysts for Suzuki-Miyaura cross coupling reactions under mild and green conditions remains a challenge in the field of synthetic organic chemistry. Herein, we describe a new nanocatalyst comprising of palladium nanoparticles supported on hydroxyapatite nanospheres, which can reproducibly be formed in-situ during the Suzuki-Miyaura coupling reactions starting with Pd(II)-exchanged nanohydroxyapatite. The characterization of the resulting catalyst by using ICP-OES, P-XRD, XPS, TEM, HRTEM, SEM and N-2-adsorption-desorption analyses revealed that the formation of 3.7 +/- 1.3nm palladium(0) nanoparticles (Pd(0)(similar to 430) nanoclusters) on the surface of nano-sized (similar to 50nm) hydroxyapatite (nano-HAp) support by keeping the host framework intact. This previously unappreciated combination of Pd NPs and nano-HAp (PdNPs@nano-HAp) shows excellent activities (TOF's > 3x10(5) h(-1)) in the Suzuki-Miyaura cross coupling reactions of different arylbromides with phenylboronic acid under mild, green and aerobic conditions. More importanly, these new supported palladium(0) nanoparticles were found to be highly durable nanocatalyst throughout the reusability experiments, they maintain almost their inherent activity after 10(th) catalytic cycle at high conversion (> 98%).Öğe The antimicrobial activity of essential oils of Hypericum scabrum, Hypericum scabroides and Hypericum triquetrifolium(Wiley, 2004) Kızıl, Göksel; Toker, Zuhal; Özen, Hasan Çetin; Aytekin, ÇetinThe essential oils of Hypericum scabrum, Hypericum scabroides and Hypericum triquetrifolium were studied for the first time for their antimicrobial activity against nine organisms. All the essential oils exhibited some broad spectrum antibacterial activity, at a concentration of 80 mug/mL. The essential oils of Hypericum species showed antibacterial activity against the tested organisms and a yeast. Copyright (C) 2004 John Wiley Sons, Ltd.Öğe Ultrasound- and microwave-promoted synthesis, growth-regulating activity and antimicrobial behavior of trimecaine-based Ionic compounds(Wiley-V C H Verlag Gmbh, 2022) Dauletbakov, Anuar; Zazybin, Alexey; Yu, Valentina; Belyankova, Yelizaveta; Ten, Assel; Rafikova, Khadichakhan; Zolotareva, Darya; Aydemir, MuratThe present work describes the synthesis, growth-regulating activity, and antimicrobial behavior of ionic compounds based on 2-diethylamino-N-(2,4,6-trimethylphenyl)acetamide (trimecaine). Synthesis of ionic compounds was performed via N-alkylation of trimecaine with alkyl halides using microwave and ultrasound activation and the results were compared with those of classical conditions (thermal activation). The synthesized ionic compounds have been tested for germination energy and capacity with the collection of different varieties and hybrids of sweet sorghum seeds. The valuable results were obtained for the seeds stored for several years for which the significant drop in germination activity is usually observed. Furthermore, the ionic compounds were used to study their biological activity - growth -regulating activity on sweet sorghum seeds and the antimicrobial behavior against E. coli, S. typhimurium, B. subtilis, S. aureus, P. aeruginosa, and C. albicans microorganisms.Öğe Reversible immobilization of glycoamylase by a variety of Cu2+-chelated membranes(Wiley, 2012) Baydemir, Gözde; Derazshamshir, Ali; Andaç, Müge; Andaç, Cenk; Denizli, AdilGlycoamylase (AMG) is an ?-amylase enzyme which catalyzes the breakdown of large a(1,4)-linked malto-oligosaccharides to glucose. It is an extracellular enzyme and is excreted to the culture medium. In this study, AMG was immobilized on a variety of metal affinity membranes, which were prepared by chelating Cu2+ ions onto poly(hydroxyethyl methacrylate) (PHEMA) using N-methacryloyl-(L)-histidine methyl ester (MAH), N-methacryloyl-(L)-cysteine methyl ester (MAC), and N-methacryloyl-(L)-phenylalanine methyl ester (MAPA) as metal-chelating comonomers for reversible immobilization of AMG. The PHEMAH, PHEMAC, PHEMAPA membranes were synthesized by UV-initiated photo-polymerization and Cu2+ ions were chelated on the membrane surfaces. Cu2+-chelated membranes were characterized by swelling tests, SEM, contact angle measurements, elemental analysis, and FTIR. AMG immobilization on the Cu2+-chelated membranes was performed by using aqueous solutions of different amounts of AMG at different pH values and Cu2+ loadings. Durability tests concerning desorption of AMG and reusability of the Cu2+-chelated membranes yielded acceptable results. It was computationally determined that AMG possesses four likely Cu2+/Zn2+ binding sites, away from the catalytic site, to which the metal-chelated membranes can be efficiently used. (C) 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012Öğe Cross-coupling reactions in water using ionic liquid-based palladium(II)-phosphinite complexes as outstanding catalysts(Wiley, 2014) Meriç, Nermin; Aydemir, Murat; Işık, Uğur; Ocak, Yusuf Selim; Rafikova, Khadichakhan; Paşa, Salih; Kayan, Cezmi; Durap, Feyyaz; Temel, Hamdi; Zazybin, Alexey G.; 0000-0003-0899-1948; 0000-0002-6244-9327; 0000-0002-4792-8821Two new phosphinite ligands based on ionic liquids [(Ph2PO)C7H14N2Cl]Cl (1) and [(Cy2PO)C7H14N2Cl]Cl (2) were synthesized by reaction of 1-(3-chloro-2-hydoxypropyl)-3-methylimidazolium chloride, [C7H15N2OCl]Cl, with one equivalent of chlorodiphenylphosphine or chlorodicyclohexylphosphine, respectively, in anhydrous CH2Cl2 and under argon atmosphere. The reactions of 1 and 2 with MCl2(cod) (M=Pd, Pt; cod=1,5-cyclooctadiene) yield complexes cis-[M([(Ph2PO)C7H14N2Cl]Cl)(2)Cl-2] and cis-[M(Cy2PO)C7H14N2Cl]Cl)(2)Cl-2], respectively. All complexes were isolated as analytically pure substances and characterized using multi-nuclear NMR and infrared spectroscopies and elemental analysis. The catalytic activity of palladium complexes based on ionic liquid phosphinite ligands 1 and 2 was investigated in Suzuki cross-coupling. They show outstanding catalytic activity in coupling of a series of aryl bromides or aryl iodides with phenylboronic acid under the optimized reaction conditions in water. The complexes provide turnover frequencies of 57 600 and 232 800h(-1) in Suzuki coupling reactions of phenylboronic acid with p-bromoacetophenone or p-iodoacetophenone, respectively, which are the highest values ever reported among similar complexes for Suzuki coupling reactions in water as sole solvent in homogeneous catalysis. Furthermore, the palladium complexes were also found to be highly active catalysts in the Heck reaction affording trans-stilbenes. Copyright (c) 2014 John Wiley & Sons, Ltd.Öğe Electrical and photoelectrical behaviour of heterojunctions based on novel oligomeric metal complexes(Wiley, 2015) Atlan, Metin; Ocak, Yusuf Selim; Paşa, Salih; Temel, Hamdi; Tombak, Ahmet; Kılıçoglu, Tahsin; Akkılıç, Kemal; Aydemir, Murat; 0000-0002-4238-5012; 0000-0002-4792-8821; 0000-0002-9997-1653; 0000-0002-7150-6522Naringenin-based Schiff base ligands with 4-aminobenzoic hydrazide were obtained as a unilateral form (L-1). The ligand was oligomerized by oxidative polycondensation reaction with NaOCl as an oxidant in an aqueous alkaline medium at 90 degrees C to form a functional oligomer (L-2), and its transition metal complexes such as those with Cu(II), Ni(II) and Zn(II) were prepared. The monomer and the oligomeric compounds were characterized using various techniques. Optical and electrical properties of the complexes were also investigated. All compounds showed indirect band gaps and they can be accepted as being in the semiconductor class. Organic-inorganic hybrid devices were obtained using n-Si inorganic semiconductor and the complexes. The characteristic parameters of the devices were determined using current-voltage (I-V) and capacitance-voltage measurements in the dark. Photoelectrical properties of the devices were investigated using I-V measurements under a solar simulator with an AM1.5 global filter. Copyright (C) 2015 John Wiley & Sons, Ltd.
