Person: ÖZKAYA, ALİ RIZA
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ÖZKAYA
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ALİ RIZA
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Publication Metadata only Synthesis, characterization, and electrochemical, and electrical measurements of novel 4,4 '-isopropylidendioxydiphenyl bridged bis and cofacial bis-metallophthalocyanines (Zn, Co)(PERGAMON-ELSEVIER SCIENCE LTD, 2008) ÖZKAYA, ALİ RIZA; Canlica, Mevlude; Altindal, Ahmet; Oezkaya, Ali Riza; Salih, Bekir; Bekaroglu, Oezer4,4'-Isopropylidendioxydiphenyl bridged bis-metallophthalocyanines Zn(II) (5) and Co(II) (6) were synthesized from the compound 4,4'-isopropylidendioxydiphthalonitrile (3) and 4,5-bis(hexylthio)phthalonitrile (4). The new cofacial bis-phthalocyanines Zn(II) (7) and Co(II) (8) were synthesized from the corresponding 3 which can be obtained by the reaction of 4,4'-isopropylidendiphenol (1) with 4-nitrophthalonitrile (2). These complexes have been characterized by elemental analysis, UV/Vis, FT-IR, H-1 NMR and MALDI-TOF mass spectroscopies. The electrochemical properties of the complexes were examined by cyclic voltammetry, differential pulse voltammetry and controlled potential coulometry in nonaqueous media. Electrochemical results showed that while there is not any considerable interaction between the two phthalocyanine rings in bisphthalocyanine complexes 5 and 6, the splitting of the molecular orbitals occurs as a result of the strong interaction between the phthalocyanine rings in cofacial complexes 7 and 8. Measurements of capacitance showed a well defined decrease with increasing frequency and an increase with increasing temperature at lower frequencies. (C) 2008 Elsevier Ltd. All rights reserved.Publication Metadata only Synthesis, characterization and electrochemical properties of novel metal free and zinc(II) phthalocyanines of ball and clamshell types(PERGAMON-ELSEVIER SCIENCE LTD, 2007) ÖZKAYA, ALİ RIZA; Ceyhan, T.; Altindal, A.; Ozkaya, A. R.; Celikbicak, O.; Salih, B.; Erbil, M. Kemal; Bekaroglu, O.The phthalodinitrile derivative I was prepared by the reaction of 4-nitrophthalonitrile and 1,3-dimethoxy-4-tert-butylcalix[4]arene in dry dimethylsulfoxide as the solvent, in the presence of the base K2CO3, by nucleophilic substitution of an activated nitro group in an aromatic ring. The tetramerization of compound I gave a binuclear zinc(II) phthalocyanine and a metal-free phthalocyanine of the ball type, 2 and 3, respectively. Its condensation with 4,5-bis(hexylthio)phthalonitrile results in a binuclear plithalocyanine of the clamshell type, 4. The newly synthesized compounds were characterized by elemental analysis, UV-Vis, IR, MS and H-1 NMR spectra. The electronic spectra exhibit an intense pi -> pi* transition with characteristic Q and B bands of the phthalocyanine core. The electrochemical properties of 2-4 were examined by cyclic voltammetry in non-aqueous media. The voltammetric results showed that while there is no considerable interaction between the two phthalocyanine rings in 4, the splitting of a molecular orbital occurs as a result of the strong interaction between the phthalocyanine rings in 2 and 3. (c) 2007 Elsevier Ltd. All rights reserved.Publication Metadata only Coumarin-derivatized fluorescent vic-dioxime-type ligand and its complexes; the preparation, spectroscopy, and electrochemistry(SPRINGER, 2007) ÖZKAYA, ALİ RIZA; Camur, Meryem; Bulut, Mustafa; Oezkaya, Ali R.; Kandaz, Mehmet; Yayli, NurettinA new vic-dioxime bearing coumarin functionality, N-'1, N-'2-Dihydroxy-N1, N2-bis(4-methyl-2-oxo-2H-chromen-7yl) oxalimidamid (LH2), N,N-bis-[4-methylcoumarinyl]-diamino glyoxime (LH2), and its mono- and dinuclear complexes {copper(II), cobalt(II), nickel(II) and uranyl(II)} have been reported. The. uorescence excitation and emission spectra of LH2 and its complexes with metal ions were examined. It was observed that. uorescence and excitation emission intensity of LH2 was quenched depending on complex formation with metal ions. The characterizations of all newly synthesized compounds were made by elemental analysis, H-1-n.m.r,i.r.,u.v.-vis., and l.c-m.s. m.s. data. Electrochemical behaviour of the ligand involving oxime and coumarine moieties, and its complexes with Ni-II, Cu-II, Co-II and UO2II were investigated by cyclic voltammetry. The comparison of the electrochemical behaviour of the ligand with its complexes enabled us to identify metal-, oxime- and coumarine-based signals.Publication Open Access Fluorescent vic-dioxime-type ligand and its mono- and dinuclear complexes: The preparation, spectroscopy, and electrochemistry of its various complexes(ELSEVIER SCI LTD, 2008-01) ÖZKAYA, ALİ RIZA; Oezer, Metin; Kandaz, Mehmet; Oezkaya, Ali Riza; Bulut, Mustafa; Gueney, OrhanA new coumarin functionalized vic-dioxime, S,S-bis-[4-methylcoumarinyl]-dithioglyoxime (LH2), and its soluble mono- and dinuclear complexes [nickel(II), copper(II), cobalt(II), and uranyl(II)] have been reported. The fluorescent properties of the ligand and its complexes are due to the 7-mercapto-4-methylcoumarin fluorophore, which is conjugated with vic-dioxime that functions as the MN4 core. Fluorescence spectra of the probe showed a clear shift in excitation wavelength maxima upon metal binding indicating its potential use as ratio-metric metal indicator. The fluorescence of complexes was found to be highly sensitive to both polarity and protic character of the solvent used. Both mononuclear (LH)(2)M (M = Ni, Cu and Co) and homodinuclear (LH)(2)(UO2)(2)(OH)(2)) complexes have been obtained with the metal ligand ratios of 1:2 and 2:2, respectively. The characterizations of all newly synthesized compounds were made by elemental analysis, H-1 NMR, FT-IR, UV-vis, and mass (LSI-MS) data. The electrochemical investigation of the Ni(II), Cu(II), Co(II) and UO2(II) Complexes in comparison with the ligand involving oxime and coumarin moieties enabled us to identify metal-, oxime- and coumarin-based signals. (C) 2006 Elsevier Ltd. All rights reserved.Publication Metadata only Synthesis and electrochemistry of soluble phthalocyanine complexes containing four peripheral dihexyl and dihexylhexylmalonate residues(SPRINGER-VERLAG WIEN, 2001) ÖZKAYA, ALİ RIZA; Kandaz, M; Ozkaya, AR; Bekaroglu, OTetrasubstituted phthalocyanines bearing four dihexylmalonate or dihexylhexylmalonate residues on the periphery (M[Pc(CH(COOC6H13)(2))(4)] or M[Pc(C(COOC6H13)(2)C6H13)(4)]; M = Pd(II), Cu(II), Co(II)) were synthesized from the anhydrous metal salts and the corresponding phthalonitriles. The complexes were only slightly soluble in polar solvents such as methanol and ethanol, but more soluble in less polar solvents such as benzene, toluene, and even hexane. The spectroscopic properties of the complexes were affected strongly by the electron withdrawing malonate units. Cyclic voltammetry on a platinum electrode in dichloromethane showed ligand-based one-electron transfers for Cu and Pd compounds, whereas the Co complex displayed metal-based or/and ligand-based one-electron transfers depending on the supporting electrolyte anion. The structures were confirmed by elemental analysis, H-1 NMR, C-13 NMR, IR, mass (EI and FAB), and UV/Vis spectroscopy.Publication Metadata only A new redox-active multisite ligand: synthesis, spectroscopy and electrochemistry of its mono and dinuclear complexes, and the interaction of (E,E)M (M = Ni) complex with Pd-II and Ag-I(PERGAMON-ELSEVIER SCIENCE LTD, 2004) ÖZKAYA, ALİ RIZA; Kandaz, M; Koca, A; Ozkaya, ARA novel redox active (E,E)-dioxime ligand, S,S-bis-[2(2'-ferrocenemethylaminobenzyl)]-dithioglyoxime (LH2), containing ferrocene and flexible aminobenzenesulfanyl-moieties on the periphery has been synthesized from 2-(2'-ferrocenemethylamino)benzenethiol. which was obtained by the reduction of 2,2-pyridylbenzothiazolidine with a large excess of NaBH4. Mononuclear (LH)(2)M (M = Ni-II, Cu-II, Co-II, Fe-II and Mn-II), homodinuclear (LH)(2)(UO2)(2)(OH)(2) and heterotrinuclear (LH)(2)MM'X-2(n) (M = Ni-II and M' = Pd-II, X = Cl-, n = 4 and M' = Ag-1, X = NO3-, n = 2) complexes have been obtained with the metal:ligand ratios of 1:2, 2:2 and 3:2. respectively. Flexible ferrocenemethylaminobenzenesulfanyl moieties bearing two different heteroatoms, -S and -N, on the periphery of the vic-dioxime serve as weak binding sites for Pd-II and Ag-I ions. The detection of H-bonding in all complexes except the uranyl complex by IR revealed square-planar MN4 coordination of the mono- and trinuclear complexes. The MN4 coordination of the Ni-II complex was also determined by the H-1 NMR spectroscopy. The structures of the complexes were characterized by elemental analysis, H-1 NMR, IR, MS, UV-Vis spectral and cyclic voltammetry. The voltammetric analyses of the complexes showed metal, ligand, and ferrocene based signals. The redox chemistry of the complexes exhibited both M-I and M-III oxidation states of the central metals of the complexes. (C) 2004 Published by Elsevier Ltd.Publication Metadata only Synthesis, spectroscopy, electrochemistry and in situ spectroelectrochemistry of partly halogenated coumarin phthalonitrile and corresponding metal-free, cobalt and zinc phthalocyanines(PERGAMON-ELSEVIER SCIENCE LTD, 2009) ÖZKAYA, ALİ RIZA; Alemdar, Aydin; Ozkaya, Ali Rlza; Bulut, MustafaIn this study, the preparation of novel 7-hydroxy-3-(2-chloro-4-fluorophenyl)coumarin (1), the ligand, 7-(3,4-dicyanophenoxy)-3-(2-chloro-4-fluorophenyl)coumarin (2), metal-free phthalocyanine 3 and metallophthalocyanine complexes 4 and 5 (MPcs, M = Co, Zn), beta-substituted with 7-oxo-3-(2-chloro-4fluorophenyl)coumarin functional group was achieved. By the reaction of 7-hydroxy-3-(2-chloro-4-fluorophenyl)coumarin (1) with 1,2-dicyano-4-nitrobenzen in dry DMF as the solvent in the presence of K2CO3 as the base, the 7-(3,4-dicyanophenoxy)-3-(2-chloro-4-fluorophenyl)coumarin (2) was synthesized. Compound 2 reacted with Co(CH3COO)2 center dot 4H(2)O in 2-N,N-dimethylaminoethanol to furnish a novel coumarin containing cobalt(II) Phthalocyanine 4. The cyclotetramerization of 2 with Zn(CH3COO)(2)center dot 2H(2)O in 2-N,N-dimethylaminoethanol gave the novel coumarin containing Zn(II)phthalocyanine 5; while tetramerization without any metal salts in 2-N,N-dimethylaminoethanol gave the metal-free phthalocyanine 3. The structures of obtained compounds were confirmed by elemental analysis. UV-Vis, IR, MALDI-TOF mass and H-1 NMR spectra. The cyclic and differential pulse voltammetry, and in situ spectroelectrochemistry of 7-oxo-3-(2-chloro-4-fuorophenyl)coumarin substituted phthalocyanines 3, 4 and 5 allowed us to identify metal- and phthalocyanine ring-based redox processes of the complexes. (C) 2009 Elsevier Ltd. All rights reserved.Publication Metadata only A water-soluble multisite ionophore ligand bearing pyridine and aminothiophenol functionality. Synthesis, spectroscopy and electrochemistry of its complexes, and peripheral reactivity of the (E,E)M (M = Ni) complex with Pd2+ and Ag+(SPRINGER, 2004) ÖZKAYA, ALİ RIZA; Kandaz, M; Ozkaya, AR; Koca, AThe design, synthesis and coordination of a novel multisite vic-dioxime compound, LH2 containing flexible pyridine substituents and amitiophcnylsulfanyl moieties on the periphery, facilitating solubility in water as pyridinium hydrochloride salt are described. LH2 was prepared by the reaction between 2-(2-pyridylethylamino)-benzenethiol and (E,E)-dichloroglydioxime. Mononuclear [(E,E)M] (M = Ni-II, Cu-II. Co-II, Fe-II and Mn-II) and dinuclear uranyl (UO2II) complexes of LH2 were isolated and characterized with metal:ligand ratios of 1:2 and 2:2. respectively. The reaction of Na2PdCl4 . 3H(2)O and AgNo3 in DMF with the mononuclear complex, (LH)(2)Ni, resulted in the formation of the heterotrinuclear complexes [Pd2Ni(LH)(2)]Cl-4 and [Ag2Ni(LH)(2)](NO3)(2). The complexes were characterized by elemental analysis, H-1-n.m.r., u.v.-vis. spectroscopy, i.r., and MS (LSIMS). The redox properties of the complexes were studied by cyclic voltammetry.Publication Metadata only Synthesis, characterization, electrochemical and CO2 sensing properties of novel mono and ball-type phthalocyanines with four phenolphthalein units(PERGAMON-ELSEVIER SCIENCE LTD, 2008) ÖZKAYA, ALİ RIZA; Altun, Selcuk; Altindal, Ahmet; Oezkaya, A. Riza; Bulut, Mustafa; Bekaroglu, OezerThe novel mono metallo [Zn(II) 4 and Co(II) 5] and ball-type or cofacial bis-metallo [Zn(II) 6 and Co(II) 71 phthalocyanines have been synthesized from 3, which can be obtained by the reaction of 4-nitrophthalonitrile 1 with 3,3-bis(4-hydroxy-phenyl)isobenzofuran-1(3H)-one 2 (phenolphthalein). The phthalocyanines have been characterized by elemental analysis, UV-vis, IR,H-1 NMR, and mass spectroscopy. The redox behavior of the complexes was investigated by cyclic voltammetry and controlled-potential coulometry. The electrochemical measurements suggested the formation of mixed-valent species during the redox processes of bis-metallophthalocyanines 6 and 7, as a result of the intramolecular interactions between two cofacial Pc units. The effect of temperature on the CO2 sensing properties of a spin-coated thin film of 7 was also investigated. (c) 2008 Elsevier Ltd. All rights reserved.Publication Metadata only Novel phthalocyanines bearing four 4-phenyloxyacetic acid functionalities(PERGAMON-ELSEVIER SCIENCE LTD, 2007) ÖZKAYA, ALİ RIZA; Camur, Meryem; Ozkaya, Ali Riza; Bulut, MustafaMetal-free (2) and Co(II), Zn(II), Ni(II), Cu(II) metalloplithalocyanines (2a-d) with four 4-phenyloxyacetic acid groups on the periphery were prepared by cyclotetramerization of new p-(3,4-dicyanophenoxy)phenylacetic acid (1) and the corresponding divalent metal salts. Further reactions of these products with thionylchloride and then benzylamine in tetrahydrofuran, and octanol in pyridine gave amide (3, 3a-d) and ester (4, 4a-d) derivatives, respectively. The new compounds have been characterized by elemental analyses, IR, UV-Vis, mass and H-1 NMR spectroscopy. The redox. properties of compounds 2 and 2a-d were identified by cyclic voltammetry. (C) 2007 Elsevier Ltd. All rights reserved.