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Öğe Adsorptive removal of Cu(II) and Ni(II) ions from aqueous media by chemical immobilization of three different aldehydes(ELSEVIER, 2011) Dumrul, Hakan; Kursunlu, Ahmed Nuni; Kocyigit, Ozcan; Guler, Ersin; Ertul, SerefThe three aldehydes were chemically immobilized onto silica gel modified with 3-aminopropyltrimethoxy silane, just as the classic condensation reaction of Schiff bases. The obtained silica gel structures used as adsorbent were characterized by infrared spectroscopy, elemental analysis and thermogravimetric analysis. The adsorption capabilities of these adsorbents towards Cu(II) and Ni(II) from aqueous solutions were studied and values of adsorption were detected by an atomic absorption spectrometer. The maximum adsorption capacities and isotherm parameters were found from the Langmuir and Freundlich equations. The characteristics of Ni(II) and Cu(II) metal bindings were interpreted by using Scatchard plot graphics, and it was showed that in different concentrations multi-type and/or nonspecific interactions among metal ions and modified silica gel structures were the prevailing effects causing the Ni(II) and Cu(II) adsorptions. Conclusively, probable benefit of each specific binding type in adsorptions of Ni(II) and Cu(II) from aqueous media has been discussed in detail. Crown Copyright (C) 2010 Published by Elsevier B.V. All rights reserved.Öğe Bodipy/dipyridylamino-based "turn-on" fluorescent chemosensor for trivalent chromium cations: characterization and photophysical properties(ROYAL SOC CHEMISTRY, 2015) Kursunlu, Ahmed Nuri; Sahin, Emel; Guler, Ersin{{3,5-Bis[4,4-difluoro, 8-(2,6-diethyl,1,3,5,7-tetramethyl-4-bora-3a, 4a-diaza-s-indacene)]}}phenyl-N,N-di( pyridin-2-yl) benzamide (Bodipy-DPy) was designed as an efficient fluorescent chemosensor for Cr(III). The structure of Bodipy-DPy was confirmed by UV-vis spectroscopy, fluorometry, melting point analysis, H-1-NMR, C-13-NMR, elemental analysis and ESI-TOF-MS. Its photophysical properties was investigated by absorption, emission and excitation techniques. Based on chelation assisted fluorescence enhancement, a fluorometric method was developed for trace level detection, selectivity and concentration studies of chromium(III) in EtOH-H2O. The fluorescent ligand behaved as a chemosensor for Cr(III) cations and showed a strong red fluorescence upon coordination with Cr(III), whereas almost no fluorescence was observed for the other metal cations studied. The Bodipy-DPy has absorption and emission maxima at 528 nm and 535 nm, respectively. The equilibrium binding constant of Bodipy-DPy with Cr(III) was calculated as 1.17 x 10(6) from the Stern-Volmer equation.Öğe Chemical modification of silica gel with synthesized new Schiff base derivatives and sorption studies of cobalt (II) and nickel (II)(ELSEVIER SCIENCE BV, 2009) Kursunlu, Ahmed Nuri; Guler, Ersin; Dumrul, Hakan; Kocyigit, Ozcan; Gubbuk, Ilkay HilalIn this study, three Schiff base ligands and their complexes were synthesized and characterized by infrared spectroscopy (IR), thermogravimetric analyses (TGA), nuclear magnetic resonance (NMR), elemental analysis and magnetic susceptibility apparatuses. Silica gel was respectively modified with Schiff base derivatives, (E)-2-[(2-chloroethylimino)methyl]phenol, (E)-4-[(2-chloroethylimino) methyl]phenol and N,N'-[1,4-phenilendi(E)methylidene]bis(2-chloroethanamine), after silanization of silica gel by (3-aminopropyl)trimethoxysilane (APTS) by using a suitable method. Characterization of the surface modi. cation was also performed with IR, TGA and elemental analysis. The immobilized surfaces were used for Co(II) and Ni(II) sorption from aqueous solutions and values of sorption were detected by atomic absorption spectrometer (AAS). (C) 2009 Elsevier B.V. All rights reserved.Öğe Cu (II) Chemosensor Based on a Fluorogenic Bodipy-Salophen Combination: Sensitivity and Selectivity Studies(SPRINGER/PLENUM PUBLISHERS, 2016) Kursunlu, Ahmed Nuri; Sahin, Emel; Guler, ErsinA new fluorescent chemosensor (Bodipy-S) derived from Bodipy and Salophen was developed. After the characterization of all compounds, the behavior of the chemosensor Bodipy-S toward p, d and f block-metal ions was investigated by UV-vis and fluorescence spectroscopy. This chemosensor can selectively detect to Cu (II) in methanol-aqueous solution based on chelation enhanced fluorescence (CHEF) and it almost exhibit to a fluorescence quenching effect with 20-fold. The binding constant of the fluorophore was interpreted by using of the Stern-Volmer method and the complex stoichiometry was defined by using Job's plot. Moreover, the effect of pH was performed by the fluorescence intensities of Bodipy-S in presence of Cu(II) ions. The chemosensor can be successfully used to the detection of Cu(II) in most areas.Öğe The example of calix[4]pyrrole derivative containing Bodipy unit: Fluorometric and colorimetric sensor for F- ion(PERGAMON-ELSEVIER SCIENCE LTD, 2014) Taner, Bilge; Kursunlu, Ahmed Nuri; Guler, ErsinA novel chemosensor based on calix[4]pyrrole derivative modified by Bodipy unit has been synthesized, and its complexes with various anions were investigated. The results show that the receptors can selectively recognize biologically important fluoride ions. The binding affinity for fluoride ions was investigated by naked-eye color change, absorption, emission, proton nuclear magnetic resonance spectroscopy. The addition of fluoride ions to an acetonitrile solution of chemosensor can result in an obvious color change (brownish yellow color to straw yellow). The stoichiometries between the receptor and fluoride were determined from the molar ratio plots using the UV-visible spectra, which showed evident 1:1. The proton nuclear magnetic resonance spectral data supported the fluoride anion recognition with the disappearance of the amino proton peaks. Published by Elsevier B.V.Öğe Facile assembly of Bodipy-based metal ion sensor using click chemistry(TAYLOR & FRANCIS LTD, 2013) Kursunlu, Ahmed Nuri; Guler, ErsinIn this study, two novel 4,4-difluoro-4-bora-3a,4a-diaza-s-indacenes (BODIPY)-based metal ion sensors were synthesised using click' chemistry. The coordination modes and binding constants of the complexes formed with a range of metal ions were calculated. Results indicate that both BODIPY molecules can potentially serve as fluorescent sensors for the studied metal cations. The results also show that the BODIPY-based sensors have more selectivity for Zn (II) ions in the presence of other metal ions.Öğe Fe (III), Co(II), Ni(II), Cu(II) and Zn(II) complexes of schiff bases based-on glycine and phenylalanine: Synthesis, magnetic/thermal properties and antimicrobial activity(ELSEVIER SCIENCE BV, 2018) Sevgi, Fatih; Bagkesici, Ugur; Kursunlu, Ahmed Nuri; Guler, ErsinZinc (II), copper (II), nickel (II), cobalt (II) and iron (III) complexes of Schiff bases (L-G, L-P) derived from 2-hydroxynaphthaldehyde with glycine and phenylalanine were reported and characterized by H-1 NMR, C-13 NMR, elemental analyses, melting point, FT-IR, magnetic susceptibility and thermal analyses (TGA). TGA data show that iron and cobalt include to the coordinated water and metal:ligand ratio is 1:2 while the complex stoichiometry for Ni (II), Cu (II) and Zn (II) complexes is 1:1. As expected, Ni (II) and Zn (II) complexes are diamagnetic; Cu (II), Co (II) and Fe (III) complexes are paramagnetic character due to a strong ligand of L-G and L-P. The L-G, L-P and their metal complexes were screened for their antimicrobial activities against five Gram-positive (Staphylococcus aureus, Methicillin resistant Staphylococcus aureus (MRSA), Bacillus cereus, Streptococcus mutans and Enterococcus faecalis) and three Gram-negative (Escherichia coli, Klebsiella pneumoniae and Pseudomonas aeruginosa) and one fungi (Candida albicans) by using broth microdilution techniques. The activity data show that ligands and their metal complexes exhibited moderate to good activity against Gram-positive bacteria and fungi. (C) 2017 Elsevier B.V. All rights reserved.Öğe Fluorogenic ferrocenyl Schiff base for Zn2+ and Cd2+ detection(SPRINGER, 2017) Findik, Mukerrem; Ucar, Asuman; Bingol, Haluk; Guler, Ersin; Ozcan, EmineA novel sensor based on acetylferrocene-containing Schiff base (ASB) was synthesized by reaction of alpha-chloroacetylferrocene and N-(salicylidene)-l-valinmethylester. The structure of the compound was characterized by using elemental analysis and Fourier-transform infrared (FT-IR), H-1 nuclear magnetic resonance (NMR), and C-13 NMR spectroscopy. Its metal-cation-sensing properties were investigated spectrofluorometrically. ASB served as selective chemosensor for Zn2+ and Cd2+ towards alkali, alkaline-earth, and various heavy-metal ions. It showed significant fluorescence enhancement for Zn2+ and Cd2+ ions, stemming from C=N isomerization and chelation-enhanced fluorescence. The binding modes of the complexes were determined to have 1:1 complexation stoichiometry, and the binding constants were calculated as (6.93 +/- 0.25) x 10(6) M-1 for ASB center dot Zn (2+) and (7.49 +/- 0.18) x 10(5) M-1 for ASB center dot Cd (2+) using the nonlinear curve-fitting method.Öğe Heavy metal accumulation in wheat plants irrigated by waste water(EDITURA ACAD ROMANE, 2006) Karatas, Mustafa; Dursun, Sukru; Guler, Ersin; Ozdemir, Celaletttn; Argun, M. EminHeavy metals, known as a highly pollutant group with toxic and carcinogen effects, tend to accumulate in living organisms. As the farmers of Konya began to use the wastewate of the dischare, channels for agricultural irrigation, the productive soils have been polluted for a long time period, and the plants growing in the vicinity of the discharge channel were negatively affected. The study investigates heavy metals accumulation in 60 wheat samples collected from wastewater-irrigated fields around discharge channels, during the growth period of plants. Results of this study showed that sewage channel water application for field watering increased the heavy metals (Cu, Cr, Mn, Ni, Pb and Zn) content in the root, body and seed parts of wheat plant, the increases recorded being higher for Mn and Zn.Öğe A highly selective fluorescent sensor for mercury (II) ion based on Bodipy and Calix[4]arene bearing triazolenaphthylene groups; synthesis and photophysical investigations(ELSEVIER SCIENCE SA, 2017) Sulak, Mine; Kursunlu, Ahmed Nuri; Girgin, Burcu; Karakus, Ozlem Ozen; Guler, ErsinA highly selective and sensitive fluorescent sensor for mercury ion has been obtained from a combination of Bodipy and Calix[4]arene derived by click chemistry. The structural characterization of all compounds had been carried out by FT-IR, H-1 NMR, C-13 NMR, MS, elemental analysis or melting point. Calix[4]-B including a calix[4]arene and two Bodipy units is a good fluorescent sensor for Hg(II). It can be explained by the coordination between mercury and the triazole rings. In a co-solvent of methanol and water, the complexation ratio for Calix[4]-B/Hg(II) was determined as 1:1 and the binding constant was found to be 3.42 x 10 (7) M-1. The detection of Hg(II) by Calix[4]-B works selectively in aqueous methanol mixture. (C) 2017 Elsevier B.V. All rights reserved.Öğe The investigation of complexation properties and synthesis of the (salen and salophen)-bridged Fe/Cr(III) capped complexes of novel Schiff bases(SPRINGER, 2010) Kocyigit, Ozcan; Guler, ErsinThis article describes synthesis of novel Schiff base and its complexation properties with Fe(III) and Cr(III). Firstly 1,3,5-tris (formylphenoxymethyl)benzene (1, TRIPOD) with tris aldehyde groups were synthesized using the 1,3,5-trisbromomethylbenzene and 4-hydroxybezaldehyde. The compound 1 was converted to the Schiff base derivative (2, TCPIM-TRIPOD) with p-aminobenzoic acid. The prepared TCPIM-TRIPOD were reacted with four new trinuclear Fe(III) and Cr(III) complexes involving tetradenta Schiff bases N,N-bis(salicylidene)ethylenediamine-(salenH(2)) or bis(salicylidene)-o-phenylenediamine-(salophenH(2)) and characterized by means of elemental analysis carrying out infrared spectroscopy (IR), thermogravimetric analysis (TG), nuclear magnetic resonance (H-1-NMR), elemental analysis and magnetic susceptibility measurement. The complexes can also be characterized as low-spin distorted octahedral Fe(III) and Cr(III) bridged by carboxylic acids. The tricarboxylic acids play a role as bridges for weak antiferromagnetic intramolecular exchange.Öğe A new calix[4]azacrown ether based boradiazaindacene (Bodipy): Selective fluorescence changes towards trivalent lanthanide ions(ELSEVIER SCI LTD, 2013) Bayrakci, Mevlut; Kursunlu, Ahmed Nuri; Guler, Ersin; Ertul, SerefWe report on the synthesis and photophysical properties of a new calix[4]azacrown derivative, capped with two amide bridges, in the cone conformation bearing two boradiazaindacene (Bodipy) groups at the narrow rim. Its binding properties towards trivalent lanthanide ions such as La3+, Gd3+, Tb3+, Dy3+, Er3+ and Yb3+ were investigated by using spectroscopic techniques. With respect to fluorescence intensity changes upon trivalent lanthanide ion complexation, calix[4]azacrown ether based Bodipy showed higher selectivity towards Yb3+ ion over other ions. Presence of proximal two amide groups in calix[4] azacrown ether based Bodipy were observed to play an important role in exhibiting its lanthanide ion binding. (C) 2013 Elsevier Ltd. All rights reserved.Öğe A novel Bodipy-Dipyrrin fluorescent probe: Synthesis and recognition behaviour towards Fe (II) and Zn (II)(ELSEVIER SCI LTD, 2012) Kursunlu, Ahmed Nuri; Guler, Ersin; Ucan, Halil Ismet; Boyle, Ross W.We present the design, synthesis, characterization and spectral studies for a new Zn (II) and Fe (II) selective fluorescent probe, 4,4-Difluoro-8-{3-[(4-phenoxy-dipyrromethene)propoxy]}-4-bora-3a,4a-diazaindacene (DPYBODPY). DPBODPY consists of a terminal fluorophore and a selective ligand and was designed to detect significant changes in absorbance and/or fluorescence on metal ion binding. The fluorophore is based on the Bodipy unit due to its excellent photophysical properties, while the dipyrrin unit has specific recognition abilities for Fe2+ and Zn2+ ions. The combination of these two structures is optimised to achieve significant spectral changes in the presence of Fe2+ and Zn2+ ions. (C) 2012 Elsevier Ltd. All rights reserved.Öğe Novel fluorescent sensor for silver (I) based on the 3,4-bis-triazole Bodipy via dual-click chemistry(ELSEVIER SCIENCE BV, 2017) Kursunlu, Ahmed Nuri; Guler, ErsinThis investigation paper relates with a novel dual-Bodipy derivative obtained by using 'click' chemistry. The synthesized compounds were characterized by some techniques as H-1 NMR, C-13 NMR, B-11-NMR, F-19 NMR, FT-IR, Uv vis, spectrofluorimetry, mass, elemental analysis, melting point. The photophysical measurements were conducted on 4,4-difluoro-8-(443-(843,4-Bis(1,2,3 triazolomethoxy)benzaldehyde)}propoxy))phenyl-4-bora-3a,4a, diaza-s-indacene (Bodipy-T) in presence of different metal ions. General trends were performed for emission, absorption, excitation, complex stoichiometry, different concentrations, competing ion, binding constants etc. in methanolic medium. Bodipy-T can be potentially served as a sensitive and selective ratiometric sensor for Ag (1) ion, moreover, it includes a modifiable group (aldehyde) for the preparing of its new derivatives. (C) 2017 Elsevier B.V. All rights reserved.Öğe Novel magnetite nanoparticle based on BODIPY as fluorescent hybrid material for Ag(I) detection in aqueous medium(ELSEVIER, 2016) Kursunlu, Ahmed Nuri; Ozmen, Mustafa; Guler, ErsinThis manuscript describes a highly selective and ultra-sensitive detection of Ag(l) in aqueous solution using amine coated magnetite nanoparticles modified boron-dipyrromethene by spectrofluorometer. Fe3O4 nanoparticles were synthesized by co-precipitation of Fe2+ and Fe(3+)in an ammonia solution. Amine modified Fe3O4 was prepared by using (3-aminopropyl)triethoxysilane as silanization agent. The covalent binding of boron-dipyrromethene to amine modified Fe3O4 was confirmed by means of Fourier Transform infrared spectroscopy, transmission electron microscopy, dynamic light scattering, UV-vis and fluorimeter measurements and obtained nanoparticle-boron dipyrromethene structure. The binding abilities of nanoparticle-boron dipyrromethene towards different metal ions have been investigated by some spectroscopic methods as UV-vis, fluorescence spectroscopy, Job plot, etc. and the novel surface displayed high selectivity and sensitivity for Ag(I) among all tested metals. (C) 2016 Elsevier B.V. All rights reserved.Öğe Organometallic chiral Schiff base for enantio-selective fluorescent recognition of methionine(SPRINGER INTERNATIONAL PUBLISHING AG, 2017) Ucar, Asuman; Findik, Mukerrem; Bingol, Haluk; Guler, Ersin; Ozcan, EmineHerein, the synthesis and characterization of a novel chiral Schiff bases derived from ferrocene, coded as 3, have been reported. The sensing behavior of the synthesized compound has been examined towards the enantiomers of some amino acids (methionine, alanine, serine, histidine, and threonine) by spectrofluorimetric method. The fluorescence response of compound 3 showed noticeable enhancement upon addition of d-methionine compared to l-methionine and kept nearly linear correlation with the concentration of d-methionine. The value of enantiomeric fluorescence difference ratio (ef) has been determined to be 1.54 when d - and l- methionine amount is 100 times more than compound 3. The results showed that the compound 3 can be used as a sensor for enantio-selective recognition of d-methionine.Öğe The (salophen)-bridged Fe/Cr (III) capped complexes with triphenylene core: Synthesis and characterization(ELSEVIER SCIENCE SA, 2011) Kocyigit, Ozcan; Guler, ErsinThis article describes synthesis of the difference carboxylic acid derivatives of triphenylene and its complexation properties with Fe/Cr (III)-salophen. For this purpose, the carboxylic acid derivatives of 2,3,6,7,10,11-hexahydroxytriphenylene were synthesized and then reacted with four new Fe(III) and Cr(III) complexes involving tetradenta Schiff bases bis(salicylidene)-o-phenylenediamine-(salophenH(2)). The prepared compounds were characterized by means of elemental analysis carrying out infrared spectroscopy (IR), thermogravimetric analysis (TG), nuclear magnetic resonance (H-1 NMR), elemental analysis and magnetic susceptibility measurement. The complexes can also be characterized as low-spin distorted octahedral Fe(III) and Cr (III) bridged by carboxylic acids. (C) 2011 Elsevier B.V. All rights reserved.Öğe The sensitivity and selectivity properties of a fluorescence sensor based on quinoline-Bodipy(ELSEVIER SCIENCE BV, 2014) Kursunlu, Ahmed Nuri; Guler, ErsinA novel florescence sensor (Q-BODIPY) based on quinoline-Bodipy (quinoline-boradiazaindacene) was prepared by 'click chemistry' in several stages. The sensing actions of Q-BODIPY were confirmed by UV-vis titration, emission and excitation spectroscopic studies in presence of Mn2+, Co2+, Ni2+, Cu2+, Zn2+, Cd2+, Sn2+, Hg2+, Pb2+, La3+, Ga3+, Er3+ and Yb3+ ions in methanol:H2O (1:1) medium. Whereas some metal ions can only cause quenching effect on the fluorescence intensity of Q-BODIPY, some of them show an increase in fluorescence intensity. The stoichiometry of host-guest complexes formed was determined by Job's plot method. The binding constants were calculated by Stern-Volmer method. As a fluorescence sensor, Q-BODIPY shows the best selectivity performance against Zn2+ ions in according to all spectroscopic data. Published by Elsevier B.V.Öğe A symmetric and selective fluorescent Cu (II) sensor based on bodipy and s-triazine(ELSEVIER SCIENCE BV, 2014) Kursunlu, Ahmed Nuri; Koc, Ziya Erdem; Obali, Aslihan Yilmaz; Guler, ErsinA symmetric fluorescent sensor based on Bodipy for Cu (II) ion was designed according to binding site-signaling subunit approach. This sensor was prepared by reaction of 2,4-diamino-6-methyl-1,3,5-triazine with a 8-{4-(chloromethyl)phenyl}-2,6-diethyl-4,4-difluoro-1,3,5,7-tetramethyl-4-bora-3a,4a-diaza-s-indacene in dimethyl formamide. The synthesis and the photophysical properties of Bodipy-triazine derivative were investigated in presence of some metal ion. The results show that this symmetrical fluorescent sensor has a high selectivity for Cu (II) ion. Published by Elsevier B.V.Öğe Synthesis and characterization of nickel(II) and copper(II) complexes of the Schiff bases derived from 2,4,6-/3,5,6-trimethyl-3-cyclohexene-1-carboxaldehyde and glycine(ASIAN JOURNAL OF CHEMISTRY, 2008) Guler, ErsinIn this study, the synthesis of Schiff bases derived from 2,4,6-trimethyl-3-cyclohexene-1-carboxaldehyde or 3,5,6-trimethyl-3-cyclohexene-1-carboxaldehyde and glycine and their complexes with nickel(II) and copper(II) were investigated. The synthesized compounds were characterized by elemental analyses, conductivity measurements, magnetic properties and FT-IR spectroscopy. The Schiff base ligands and their complexes have been further characterized by (1)H NMR. The results showed that the Schiff base acts as a bidentate ligand which bonds to the metal ions through the imino nitrogen and carboxylate oxygen. The potassium salts of the Schiff bases are 1 : 1 electrolytes, but all the complexes are non-electrolytes.
