Yazar "Obali, Aslihan Yilmaz" seçeneğine göre listele
Listeleniyor 1 - 8 / 8
Sayfa Başına Sonuç
Sıralama seçenekleri
Öğe Aromatic Chromophore-Tethered Schiff Base Ligands and Their Iron(III)/Chromium(III) Salen and Saloph Capped Complexes(SPRINGER/PLENUM PUBLISHERS, 2012) Obali, Aslihan Yilmaz; Ucan, Halil IsmetAromatic chromophores; pyrene, phenanthrene, anthracene, naphtalene and benzene-tethered Schiff base ligands and their iron(III)/chromium(III) Salen and Saloph capped complexes have been synthesized. Compounds have been characterized by means of FT-IR Spectroscopy, H-1-NMR Spectroscopy, Magnetic Susceptibility, Elementel Analsis, TG/DTA measurements. Their fluorescence and absorbance properties have been investigated by Luminescence Spectroscopy and UV-vis Spectroscopy. Generally, ligands show an intense excimer fluorescence emissions in acetonitrile-methanol medium while iron(III) and chromium(III) complexes exhibit low fluorescence's. Intensity compared to ligands iron and chromium centers act as an extra chromophore that quench the pyrene, phenanthrene, anthracene, naphtalene and benzene molecules' singlet state. The mechanism of quenching is attributed to a iron (or chromium)-to-pyrene (or phenanthrene, anthracene, naphtalene and benzene) electronic energy transfer process.Öğe Design of Azide-substitued Polypyridine Ligand(IEEE, 2017) Ucan, Halil Ismet; Obali, Aslihan YilmazNovel azide-substitued polypyridine ligand, 2(4-(azidomethyl) phenyl)-1H-imidazo[4,5f][1,10] phenanthroline (N3-PPY), and its Ruthenium(II) complexes were synthesized. Their spectroscopic properties were investigated. All starting materials and reagents used were purchased from Sigma Aldrich, Merck and used without further purification. All aqueous solutions were prepared with deionized water that had been passed through a Millipore milli Q Plus water purification system. H-1-NMR spectra were taken using a Varian 400-MHz Spectrometer. FT-IR spectra were recorded using a Perkin Elmer Spectrum 100 FT-IR Spectrometer. Melting points were determined by Buchi Melting Point B-540 instrument. Elemental analyses were carried out using a LECOCHNS-932 elementel analyser.Öğe Dipodal quinoline-tethered fluorescent probe synthesis and investigation of spectroscopic properties(ELSEVIER SCIENCE BV, 2017) Obali, Aslihan Yilmaz; Yilmaz, Menzeher Serkan; Ucan, Halil IsmetNovel quinoline-tethered fluorescent probe was designed and synthesized as multidentate ligand. Their sensing actions were confirmed by UV-Vis absorbance and emission spectroscopic studies in presence of perchlorate salts of Co2+, Li+, Fe2+, K+, Pb2+, Cu2+, Zn2+, Ni2+, Hg2+, Ag+ cations in acetonitrile (1 x 10(-5) M for absorption studies, 1 x 10(-7) M for fluorescence studies). It was found that the dipodal compounds can selectively bind to Cu2+ and Ag+ metal ions with a significant quenching in their emissions. The capture of Cu2+ and Ag+ by the probe resulted in deprotonation of the secondary amine conjugated to the quinoline-tethered probe, so that the electron-donation ability of the 'N' atom would be greatly enhanced and the probe (2) showed blue-shift in emission and exhibited an on-off fluorescent response. The binding study was explored by using fluorescence spectroscopy with Job plot method. (C) 2017 Elsevier B.V. All rights reserved.Öğe Novel dipodal Schiff base compounds: Synthesis, characterization and spectroscopic studies(ELSEVIER, 2015) Obali, Aslihan Yilmaz; Ucan, Halil IsmetTwo novel dipodal Schiff base compounds 1,2-benzyloxy-bis-12-(benzylidenearnino)phenol, L1 and 1,2-benzyloxy-bis[3-(benzylideneamino)pyridine] 12 were synthesized. Their sensing actions were confirmed by UV-Vis absorbance and emission spectroscopic studies in presence of Cr(III), Mn(II), Fe(III), Co(II), Ni(II), Cu(II), Zn(II), Sn(II), Cd(II) and Pb(II) in methanol medium (1 x 10-4 M). It was found that the dipodal compounds can selectively bind to Cu(II) and Pb(II) metal ions with a significant change in its emission and absorption spectra, while the addition of other metal ions (Cr(III), Mn(II), Fe(III), Co(II), Ni(II), Cu(II), Zn(II), Sn(II), Cd(II) and Pb(II)) produces insignificant or minor changes. The host-guest complexes formed were determined by Job's plot method. As a chemosensor, L1 and L2 dipodal Schiff base compounds shows a specific selectivity towards Cu(II) and Pb(II) ions in according to all spectroscopic data. (C) 2014 Elsevier B.V. All rights reserved.Öğe Preparation of Different Substitued Polypyridine Ligands, Ruthenium(II)-Bridged Complexes and Spectoscopic Studies(SPRINGER/PLENUM PUBLISHERS, 2016) Obali, Aslihan Yilmaz; Ucan, Halil IsmetNovel different substitued polypyridine ligands 4-((4-(1H-imidazo[4,5-f][1,10]phenanthroline-2-yl)phenoxy)methyl)benzaldehyde (BA-PPY), (E)-N-(4-((4-(1H-imidazo[4,5-f][1,10]phenanthroline-2-yl)phenoxy)methyl)benzylidene)-pyrene-4-amine (PR-PPY), (E)-N-(4-((4-(1H-imidazo[4,5-f][1,10] phenanthroline-2-yl)phenoxy)methyl)benzylidene)-1,10-phenanthroline-5amine (FN-PPY), 2-(4-(bromomethyl)phenyl)-1H-imidazo[4,5-f][1,10] phenanthroline (BR-PPY), 2-(4-(azidomethyl)phenyl)-1H-imidazo[4,5-f][1,10]phenanthroline (N3-PPY) and triazole containing polypyridine ligand 3,4-bis[(4-(metoxy)-1,2,3-triazole)1-methylphenyl)-1H-imidazo[4,5-f][1,10]phenanthroline)] benzaldehyde (BA-DIPPY) and Ruthenium(II) complexes were synthesized and characterized. Their photopysical properties were investigated. The complexes RuP(PR-PPY), RuB(PR-PPY, RuP(FN-PPY) and RuB(FN-PPY) exhibited a broad absorption bands at 485, 475, 476, and 453 nm, respectively, assignable to the spin-allowed MLCT (d(pi)-pi*) transition. The emission maxima of the pyrene-appended polypyridine ligand PR-PPY was observed at lambda ems = 616 nm and the phenanthroline-appended polypyridine ligand FN-PPY was observed at lambda ems = 668 nm. And the emission maxima of the complexes RuP(PR-PPY), RuB(PR-PPY), RuP(FN-PPY) and RuB(FN-PPY) were observed at lambda ems = 646, 646, 685 and 685 nm, respectively. As seen in fluorescence spectra, the fluorescence intensities of the ligands are higher than their metal complexes. This is because of quenching effect of Ruthenium(II) metal on chromophore groups.Öğe Probing the Limits of Tetraazamacrocycle-Glyoxal Condensates as Bidentate Ligands for Cu2+(WILEY-V C H VERLAG GMBH, 2015) Won, Paul D.; Funwie, Neil L.; Birdsong, Orry C.; Obali, Aslihan Yilmaz; Burke, Benjamin P.; McRobbie, Graeme; Greenman, PeterTetracyclic bisaminals formed by condensation of tetraazamacrocycles and glyoxal have rarely been utilized as ligands for transition metal ions. Five novel Cu2+ complexes are presented to expand this set. Glyoxal derivatives of pyruvic aldehyde and butanedione were expected to further rigidify the bisaminal skeleton because of the steric requirements of the methyl groups, while the previously unutilized homocyclam was expected to increase flexibility due to the presence of a seven-membered ring. Additionally, a nitrato complex was prepared to examine the effect of more bulky monodentate ligands on the bisaminal framework. The new complexes showed similar four-coordination of Cu2+, but with significant changes in coordination geometry caused by substitution of the glyoxal bridge by one or two methyl groups. The homocyclam derivative produced a completely different coordination mode due to the flexibility of the larger macrocycle ring. Both structural and electronic properties were affected by the use of nitrato in place of the typical chlorido monodentate ligands. Overall, the electronic properties (magnetic moment, electronic spectra, and cyclic voltammetry) were only subtly affected. However, larger changes were observed when the larger homocyclam macrocycle was used or the nitrato anion was used in place of the chlorido ligand to complete the coordination. Additionally, the recently published geometric index was evaluated by using this series of closely related Cu2+ complexes.Öğe Ruthenium (II) Complexes of Mono-, Di- and Tripodal Polypyridine Ligands: Synthesis, Characterization, and Spectroscopic Studies(SPRINGER/PLENUM PUBLISHERS, 2015) Obali, Aslihan Yilmaz; Ucan, Halil IsmetMono-, di- and tripodal polypyridine ligands 4-(1H-imidazo[4,5-f][1,10]phenanthroline-2-yl)phenol (L1), 2-(4-(2-((4-(1H-imidazo[4,5-f][1,10]phenanthroline-2-yl)phenoxy)methyl)benzyloxy)phenyl)-1H-imidazo[4,5-f][1,10]phenanthroline (L2), 2-(4-(4-((4-(1H-imidazo[4,5-f][1,10]phenanthroline-2-yl)phenoxy)methyl)benzyl oxy)phenyl)-1H-imidazo[4,5-f][1,10]phenanthroline (L3), 2-(4-(4,6-bis(4-(1H-imidazo[4,5-f][1,10] phenanthroline-2-yl)phenoxy)-1,3,5-triazine-2-yloxy)phenyl)-1H-imidazo[4,5-f][1,10]phenanthroline (L4), and their Ru (II) complexes have been synthesized and characterized. All the ligands (L1-L4) gave the emissions at three shoulder at 278 nm, 315 nm, and 328 nm and the complexes (C1-C4) exhibit Ru (II) metal centered emission at 265 nm, 288 nm and 328 nm in acetonitrile solution at room temperature. Maximum d-pi* transition seen at 462 nm for all the complexes.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.
