A new chromenylium-cyanine chemosensor for switch-ON near-infrared copper (II) sensing

KARAOGLU, Kaan/0000-0003-3265-8328WOS: 000511287400010A highly selective and sensitive near-IR chemosensor having a chromenylium-cyanine backbone for the detection of Cu2+ in aqueous samples has been designed and synthesized. the sensor has exhibited linear optical response to copper ions at the range of 0-4.9 x 10(-6) M in the presence of other competing metal ions, such as Na+, K+, Mg2+, Ca2+, Cr3+, Mn2+, Fe3+, Co2+, Ni2+, Zn2+, Al3+, Cd2+, Ag+, Sr2+, Pb2+, Hg2+ and Ba2+. the limit of detection (LOD) was calculated as 1.28 x 10(-8) M which was lower than that of previously reported analogues. the sensor allows detection of the copper(II) ion through the spirocyclic ring-opening reaction by coordination of Cu2+. (C) 2019 Elsevier B.V. All rights reserved

Characterization of microplastic pollution in tadpoles living in small water-bodies from Rize, the northeast of Turkey

gul, serkan/0000-0002-0372-7462WOS: 000538127800028PubMed: 32380267Microplastic pollution is a growing problem for Turkey and other countries, but most studies focus on the pollution in oceans and seas. To understand the relationship between microplastics, fresh water, and terrestrial environment, we examined Pelophylax ridibundus and Rana macrocnemis tadpoles that can inhabit a wide range of both terrestrial and aquatic habitats, ecoregions and elevations, and that are members of Ranidae family. We characterized microplastics (MPs) in sediments, surface water, and tadpoles from the Rize province in northeastern of Turkey. the content of MPs in sediments, surface water, and tadpoles, ranged 64.17-472.1 items/kg, 1-13 items/L and 302.62-306.69 items/g, respectively. in sediment samples, polypropylene (PP) and polyethylene (PE) were the dominant pollutants; whereas, nylon and polyethylene terephthalate (PET) were found in surface water. in tadpoles, PET, nylon, and polyacrylic were the dominant MPs. (C) 2020 Elsevier Ltd. All rights reserved

New Chromenylium-cyanine based dual channel chemosensors for copper and hypochlorite sensing

Kaya, Kerem/0000-0002-5736-488X; yilmaz, ismail/0000-0002-5046-7456WOS: 000541131700073Based on a change in optical properties of chromenylium-cyanine Schiff base derivatives (5a-c), a series of colorimetric dual sensors have been for the first time designed, synthesized and characterized to monitor Cu2+ and OCl- ions at near-IR (NIR) region in aqueous samples. the colorimetric responses of the sensors toward Cu2+ and OCI- ions were evaluated for aqueous samples within a series of the competitive anions and cations at pH 7.2. the sensors detected Cu2+ selectively via Cu2+-promoted spimcyclic ring-opening reaction while photophysical change during OCl- recognition is due to the spimcyclic ring-opening reaction by coordination Cu2+ ion generated from reaction between Cu+ and hypochlorite ions in analysis media. Mass and IR data suggest a 1:1 complex formation between Cu2+ and the receptor via phenolic O atom, N atom from Schiff base and O atom from spirocycle form. the detection limits of the dual sensors (5a-c) were determined to be 3.3 x 10(-8) M, 1.93 x 10(-8) M and 2.36 x 10(-8) for Cu2+ determination and 2.83 x 10(-8) M, 2.10 x 10(-8) M and 2.60 x 10(-8) M for OCl- determination, indicating a high sensitivity of the sensors for Cu2+ and OCl- detection Additionally, we present the first single-crystal structure analysis of a chromenylium-cyanine Schiff base in this study.Scientific and Technological Research Council of Turkey (TUB_ITAK)Turkiye Bilimsel ve Teknolojik Arastirma Kurumu (TUBITAK) [217Z250]This work is supported by the Scientific and Technological Research Council of Turkey (TUB_ITAK) project number 217Z250. the numerical calculations reported in this paper were fully performed at TUBITAK ULAKBIM, High Performance and Grid Computing Center (TRUBA resources)

A New Fluorescent "Turn-Off" Coumarin-Based Chemosensor: Synthesis, Structure and Cu-Selective Fluorescent Sensing in Water Samples

KARAOGLU, Kaan/0000-0003-3265-8328; KARAOGLU, Kaan/0000-0003-3265-8328WOS: 000403468400012PubMed: 28283898We report the synthesis and characterization two coumarin-based fluorescence probes, N'-{[7-(diethylamino)-2-oxo-2H-chromen-3-yl]carbonyl}pyridine-3-carbohydrazide (3) and N'-benzoyl-7-(diethylamino)-2-oxo-2H-chromene-3-carbohydrazide (4), proposed as a novel fluorescent chemosensor. the two probes designed showed an instant turn-off fluorescence response to Cu2+ over other metal ions in ethanol-water mixture based on intramolecular charge transfer (ICT). It was found that pyridine-analogue coumarin is highly selective and sensitive sensor for Cu2+. the 3 sensor coordinates Cu2+ in 1:1 stoichiometry with a binding constant, K-a = 5.22 M-1 and the detection limit was calculated 1.97 x 10(-9) M.Recep Tayyip Erdogan University Scientific Research Project Unit (RTEUBAP) [FBA-2016-662]This work was supported by Recep Tayyip Erdogan University Scientific Research Project Unit (RTEUBAP) under the project number of FBA-2016-662. the authors thank all the colleagues in the project unit for their supportive attitude

Detection of Fe2+ in acetonitrile/water mixture by new 8-hydroxyquinolin based sensor through metal displacement mechanism

KARAOGLU, Kaan/0000-0003-3265-8328; AKCAY, Hakki Turker/0000-0002-8502-9608; yilmaz, ismail/0000-0002-5046-7456; KARAOGLU, Kaan/0000-0003-3265-8328WOS: 000393931900054A 8-hydroxyquinoline-based (8-HQ) fluorescent ligand (2) was designed and synthesized by condensation of pyridine-2-carboxaldehide with 2-(quinolin-8-yloxy)acetohydrazide (1). Fluorometric titrations with various metal ions in 1:1 M ratio showed that Cu2+ and Ni2+ ions were fully quenched the fluorescence intensity of 2. But, a significant enhancement in the fluorescent intensity was observed when the bound Ni2+ and Cu2+ ions in the 2-Ni and 2-Cu complexes were displaced by Cr3+ and Fe+2 ions, respectively. While 2-Ni exhibited low sensitivity toward Cr3+ ion, the fluorescent titration measurements showed that 2-Cu could be a good "on-off-on" selective and sensitive sensor (S) candidate for determination of Fe2+ in aqueous medium. (C) 2016 Elsevier B.V. All rights reserved

Mononuclear Cu(II) complex of an oxime ligand derived from N-Heterocyclic hydrazide: Synthesis, spectroscopy, electrochemistry, DFT calculations and catecholase activity

emirik, mustafa/0000-0001-9489-9093; KARAOGLU, Kaan/0000-0003-3265-8328WOS: 000471652700049A new oxime derivative N-heterocyclic hydrazide ligand, N'-[(1E,2E)-2-(hydroxyimino)-1-methylpropylidene]-2-[(4-methyl-5-phenyl-4H-1,2,4-triazol-3-1)thio] acetohydrazide (1) and its mono-nuclear copper(II) complex (1a) have been synthesized and characterized by using IR, UV-Vis, NMR and MALDI-TOF mass spectrometry. DFT-based molecular orbital energy calculations and electrochemical behaviors of the compounds have been also studied to explain redox potential of the compounds. the catecholase-mimetic activity of the Cu(II) complex (1a) has been investigated by monitoring the formation of 3,5-di-tert-butyl-benzoquinone from 3,5-di-tert-butylcatechol. Irreversible electrochemical ring-closing of the ligand by oxidation is proposed. Electrochemical ring-closing reaction is shielded by the coordination of Cu(II) to the oxime moiety of the ligand and the title complex undergoes quasi-reversible oxidation and irreversible reduction. Under aerobic conditions, the title copper(II) complex behaves as an effective catalyst towards oxidation of 3,5-di-tert-butylcatechol to its corresponding quinone derivative in MeOH. the turnover number was found as 100.1 h(-1). (C) 2019 Elsevier B.V. All rights reserved.Research Fund of Recep Tayyip Erdogan UniversityRecep Tayyip Erdogan University [FDK-2018-965]This work was supported by the Research Fund of Recep Tayyip Erdogan University, Project No: FDK-2018-965 (Rize/Turkey). the numerical calculations reported in this paper were performed at TUBITAK ULAKBIM, High Performance and Grid Computing Center (TRUBA Resources)

Ferrocenyl-substituted dinuclear Cu(II) complex: Synthesis, spectroscopy, electrochemistry, DFT calculations and catecholase activity

emirik, mustafa/0000-0001-9489-9093; yilmaz, ismail/0000-0002-5046-7456; KARAOGLU, Kaan/0000-0003-3265-8328; KARAOGLU, Kaan/0000-0003-3265-8328WOS: 000367482700038A new ferrocenyl-substituted heterocyclic hydrazide ligand and its Cu(II) complex were prepared. the DFT calculations were performed to determine the electronic and molecular structures of the title compounds. the electronic spectra were calculated by using time-dependent OFF method, and the transitions were correlated with the molecular orbitals of the compounds. the bands assignments of IR spectra were achieved in the light of the theoretical vibrational spectral data and total energy distribution values calculated at DFT/B3LYP/6-311-1-+G(d,p) level. the redox behaviors of the ferrocene derivatives were investigated by cyclic voltammetry. the compounds show reversible redox couple assignable to Fc+/Fc couple. the copper(II) complex behaves as an effective catalyst towards oxidation of 3,5-di-tert-butylcatechol to its corresponding quinone derivative in DMF saturated with O-2. the reaction follows Michaelis Menten enzymatic reaction kinetics with turnover numbers 2.32 x 10(3). (C) 2015 Elsevier B.V. All rights reserved.Research Fund of Recep Tayyip Erdogan University (Rize/Turkey)Recep Tayyip Erdogan University [2011.102.02.1]This work was supported by the Research Fund of Recep Tayyip Erdogan University, Project No: 2011.102.02.1 (Rize/Turkey). the numerical calculations reported in this paper were performed at TUBITAK ULAKBIM, High Performance and Grid Computing Center (TRUBA Resources)

Oxime derivative unsymmetrical azine, its Ni(II), Cu(II) and Zn(II) complexes: Synthesis, spectroscopy and catecholase activity

WOS: 0004541542000071-[(Z)-{(2E)-[(3E)-3-(hydroxyimino)butan-lidene]hydrazinylidene}methyl]naphthalen -2-ol, H2L (3) was synthesized by the agents of 2-hydroxy-1-naphtaldehyde, 2,3-butanedione monoxime and hydrazine in two steps. the structures of the compounds have been proposed by elemental analyses, spectroscopic data, that is, IR, H-1 NMR, UV-vis, X-ray, mass spectra (ESI or TOF), molar conductivities and magnetic susceptibility measurements. the ligand has potentially three nitrogens and an oxygen donor to be able to bind a metal center. in the light of analytical and physical results, it was suggested that the ligand may coordinate to by N,O/N2/N2O donor set to form square planar, octahedral, distorted square planar and tetrahedral complexes. Proton NMR evidence indicating that the ligand coordinates the metal ion through the phenolic oxygen and nitrogen of imine in the nickel and zinc complexes. Molar conductivity measurements reveal that all the complexes are non-electrolytes. in addition, catecholase activities of the complexes were studied. However, the only one of the complexes, 1b, behaves as an effective catalyst toward oxidation of 3,5-di-tert-butylcatechol (3,5-DTBC) to its corresponding quinone derivative in MeOH saturated with O-2. the reaction follows Michaelis-Menten enzymatic reaction kinetics with turnover numbers (kcat) 1.19x10(3)/hour.Research Fund of Recep Tayyip Erdogan UniversityRecep Tayyip Erdogan University [2015.53002.102.02.01]This work was supported by the Research Fund of Recep Tayyip Erdogan University [grant number 2015.53002.102.02.01

Synthesis, in vitro DNA interactions, cytotoxicities, antioxidative activities, and topoisomerase inhibition potentials of Mn(II), Co(II), Ni(II), Cu(II), and Zn(II) complexes with azo-oxime ligands

Mn(II), Co(II), Ni(II), Cu(II), and Zn(II) transition metal complexes of 2-hydroxy-5-[(E)-(4-phenyl) diazenyl] benzaldehyde oxime and 2-hydroxy-5-[(E)-(4-nitrophenyl) diazenyl] benzaldehyde oxime ligands were synthesized and characterized through NMR, IR, ESI mass, and UV analysis. DNA binding abilities of the complexes were revealed using a UV-Vis spectrophotometer with the absorption titration and competitive binding techniques. Hydrolytic and oxidative DNA cleavage activities under different conditions were also proved. Topoisomerase I inhibition efficiencies and in vitro free radical scavenging activities of all complexes were examined. Finally, the selective cytotoxic potentials of all complexes were evaluated in human colon cancer, normal colon, and fibroblast cell lines using the water-soluble tetrazolium salt (WST-1) assay. The complexes had the ability to intercalate into stacked base pairs of DNA and topoisomerase I activity was reasonably inhibited in their presence in 0.4 mM concentrations. The abilities for scavenging of DPPH and hydroxyl radicals were found to be higher than those of known standard antioxidants (ascorbic acid, butylated hydroxyanisole, and mannitol). The results obtained from the cytotoxicity experiments are especially promising for further research, which must be carried out for the evaluation of the studied complexes as anticancer drugs