Yazar "Bayrak, Riza" seçeneğine göre listele

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    A spectroscopic study on new phthalonitrile derivative and its computational background: 4-[(4,5-Diphenyl-4H-1,2,4-triazol-3-yl)sulfanyl]benzene-phthalonitrile
    (Elsevier, 2017) Akcay, Hakki Turker; Coruh, Ufuk; Bayrak, Riza; Mentese, Emre; Vazquez Lopez, Ezequiel M.
    Heterocyclic phthalonitrile derivatives are important precursors in synthesis of new photoactive phthalocyanine compounds. In this study, novel phthalonitrile compound bearing triazole moiety was synthesized and characterized by using spectroscopic techniques such as FT-IR and NMR. The molecular structures of the title compound was analyzed crystallographically and compared with the structural parameters obtained computationally. The orbital energies, electronic absorptions, atomic charge parameters, vibrational frequencies, ground state transitions, H-1 and C-13 NMR chemical shifts and NBO analysis were computed by using DFT (Density Functional Theory) calculation and compared with the experimental results. (C) 2016 Elsevier B.V. All rights reserved.
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    An investigation of gamma ray mass attenuation from 80.1 to 834.86 keV for fabric coating pastes used in textile sector
    (Springer Singapore Pte Ltd, 2020) Erenler, Alev; Bayram, Tuncay; Demirel, Yusuf; Cengiz, Erhan; Bayrak, Riza
    In the present study, we investigate several textile coating pastes used in the market based on their radiation protection capability for gamma rays. The gamma ray mass absorption coefficients of some coating pastes doped with antimony, boron and silver elements have been investigated. It has been determined that the gamma ray mass attenuation coefficient decreases rapidly as the energy of the gamma rays increases. It was determined that the doping of the main printing paste with silver and antimony considerably increased the gamma ray absorption capability of main paste. However, the doping of the paste with boron reduces the mass absorption of gamma rays. In particular, the gamma ray mass absorption power of the main paste doped with silver and antimony was determined to be useful in the gamma energy range from 80 to 140 keV. This indicates that the newly doped textile material may be considered for radiation protection in the case of low-energy gamma rays .
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    Computational studies on the anastrozole and letrozole, effective chemotherapy drugs against breast cancer
    (Pergamon-Elsevier Science Ltd, 2014) Akcay, Hakki Turker; Bayrak, Riza
    In this paper, computational studies were carried out on anastrozole and letrozole, chemotherapy drugs used against breast cancer. Optimization and frequency calculations were performed at B3LYP/6-31G (d) basis set and vibrational frequencies were assignment. Single point calculations were performed at DFT method with a hybrid functional B3LYP/6-311G (d, p) basis set. Theoretical NMR data were obtained at DFT method with a hybrid functional B3LYP/6-311G++ (2d, p) with GIAO (Gauge-Independent Atomic Orbital). IEF-PCM method was used as solvation model. NBO calculations were performed by the same basis set and calculation method with single point calculation. Global and localized reactivity parameters; fukui indices (f) chemical hardness (eta) softness (S), chemical potential (mu), electronegativity (chi) and electrophilicity index (omega) were calculated. All computational parameters were compared with the experimental results obtained from the literature. (C) 2013 Elsevier B.V. All rights reserved.
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    Electrochemical and spectroelectrochemical properties of thiadiazole substituted metallo-phthalocyanines
    (Pergamon-Elsevier Science Ltd, 2016) Demirbas, Umit; Akyuz, Duygu; Barut, Burak; Bayrak, Riza; Koca, Atif; Kantekin, Halit
    4-Thiadiazole substituted phthalonitrile and peripherally tetra-substituted phthalocyanine Cu(II), Fe(II) and Ti(IV)O complexes have been synthesized for the first time. Electrochemical properties of these complexes were determined with voltammetric and in situ spectroelectrochemical measurements. CuPc has redox inactive Cu2+ center, therefore it gave three Pc based reduction and two Pc based oxidation processes. TiOPc and FePc complexes gave metal based redox processes in addition to Pc based redox reactions due to the redox activity of Ti4+O and Fe2+ metal centers. Although FePc also gave three reduction and two oxidation reactions, peak potentials of these processes are different than those of CuPc due to the different assignments of the redox reactions. TiOPc went to five reduction and one oxidation reactions. Assignments of the redox processes were carried out with in situ spectroelectrochemical measurements. Spectra and color of the electrogenerated redox species of the complexes were also determined with in situ spectroelectrochemical and in situ electrocolorimetric measurements. Distinct color differences between the electrogenerated redox species were observed, which indicated their possible electrochromic usages. (C) 2015 Elsevier B.V. All rights reserved.
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    Metal-free, zinc(II) and lead(II) phthalocyanines functioning with 3-(2H-benzo[d][1,2,3]triazol-2-yl)-4-hydroxyphenethyl methacrylate groups: Synthesis and investigation of photophysical and photochemical properties
    (Elsevier Science Sa, 2016) Demirbas, Umit; Piskin, Mehmet; Barut, Burak; Bayrak, Riza; Durmus, Mahmut; Kantekin, Halit
    In this study, the synthesis and characterization of 3-(2H-benzo[d][1,2,3]triazol-2-yl)-4-hydroxyphenethyl methacrylate substituted novel phthalonitrile compound and its peripherally substituted zinc(II) lead(II) and metal-free phthalocyanine derivatives were performed for the first time. This novel compounds were characterized by obtained data from general spectroscopic methods such as FT-IR, H-1 NMR, C-13 NMR and mass. The photophysical and photochemical properties of these phthalocyanines were investigated in N,N-dimethylformamide solutions for determination of their photosensitizing abilities in photocatalytic applications such as photodynamic therapy. The lead(II) phthalocyanine complex did not produce any fluorescent in N,N-dimethylformamide because of the heavy atom effect of bigger lead atom. The fluorescence quantum yields of studied zinc(II) and metal-free phthalocyanines were found to quite higher than unsubstituted zinc(II) phthalocyanine due to substitution of the phthalocyanine skeleton. The influence of substituent and variety of the central metal ions on spectroscopic, photophysical and photochemical properties were also determined and compared. (C) 2016 Elsevier B.V. All rights reserved.
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    New dye sensitized photocatalysts: Copper(II)-phthalocyanine/TiO2 nanocomposite for water remediation
    (Elsevier Science Sa, 2016) Albay, Cansu; Koc Kesir, Melek; Altin, Ilknur; Bayrak, Riza; Degirmencioglu, Ismail; Sokmen, Munevver
    In this study, a group of novel copper azomethyn-bridged phenolic phtalocyanines (CuPc) were synthesized. These derivatives are completely new, synthesis and characterization studies are first time reported. Four derivatives which have peripheral or non-peripheral substitution on macrocyclic ring were produced and characterized employing various spectroscopic methods. CuPc were immobilized on TiO2 nanoparticles to obtain dye sensitized photoactive nanocomposites (1% of the mass of TiO2). Prepared composites were characterized by SEM, EDX, UV-vis, DRS and XRD analysis. Results revealed that the composites possess anatase structure and phthalocyanine loading on TiO2 exposes strong visible light absorption. Photocatalytic activities of the produced composite materials were tested for reduction of Cr(VI) as a model pollutant and its disinfection properties were investigated using Escherichia coli as a model microorganism employing a near visible UV-A light (365 nm) source. All composite materials exhibited much more photocatalytic activity than bare TiO2 for both pollutants. (C) 2016 Elsevier B.V. All rights reserved.
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    Novel triazole substituted phthalocyanines showing high singlet oxygen quantum yields
    (Elsevier, 2019) Demirbas, Umit; Bayrak, Riza; Dilber, Gulsev; Mentese, Emre; Akcay, Hakki Turker
    In this study, novel triazole peripherally substituted phthalocyanine zinc(II) complexes 3(a-d) were synthesized from four different phthalonitrile derivative and characterized by FT-IR NMR, MALDI-TOF, UV-Vis methods. Aggregation-concentration relations of the compounds 3(a-d) were investigated by UV-Vis spectroscopy. Fluorescence quenching properties of the phthalocyanines 3(a-d) were studied and fluorescence quantum yields were calculated by comparative method. Photodegradation quantum yields of the compound 3(a-d) were calculated. In addition, singlet oxygen quantum yields of the compounds 3(a-d) were measured by comparative method by using 1,3-diphenylisobenzofuran (DPBF) as singlet oxygen quencher. In this work, it has been observed that the synthesized novel phthalocyanines have higher quantum yield values (the range of 0.8-0.85) compared to the Zn (II) complex of unsubstituted phthalocyanine (0.67). Especially the compound 3d substituted tolyl group has the highest singlet oxygen quantum yield (0.85) seen rarely in literature.
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    Peripherally and non-peripherally tetra-benzothiazole substituted metal-free zinc (II) and lead (II) phthalocyanines: Synthesis, characterization, and investigation of photophysical and photochemical properties
    (Elsevier, 2017) Demirbas, Umit; Gol, Cem; Barut, Burak; Bayrak, Riza; Durmus, Mahmut; Kantekin, Halit; Degirmencioglu, Ismail
    In this study, novel phthalonitrile compounds bearing 2-methylbenzofdlthiazol-5-yloxy groups (4 and 5) and their peripherally and non-peripherally tetra-substituted metal-free (6 and 7), zinc (II) (8 and 9), and lead (II) (10 and 11) phthalocyanine derivatives were synthesized and characterized for the first time. These novel compounds showed extremely good solubility in most common organic solvents. The novel phthalocyanine compounds presented excellent results from photophysical and photochemical examinations in DMF solution. Especially, the singlet oxygen quantum yield (Phi(Delta)) values of the substituted zinc (II) phthalocyanines indicate that these compounds have significant potential as photosensitizers in cancer treatment by the photodynamic therapy (PDT) technique. The fluorescence quenching behaviour of these novel phthalocyanine compounds by 1,4-benzoquinone (BQ) was also examined in DMF solution. (C) 2016 Elsevier B.V. All rights reserved.
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    Preparation of phthalocyanine/TiO2 nanocomposites for photocatalytic removal of toxic Cr(VI) ions
    (Elsevier, 2016) Bayrak, Riza; Albay, Cansu; Koc Kesir, Melek; Altin, Ilknur; Degirmencioglu, Ismail; Sokmen, Munevver
    In this study, a group of novel metal free azomethine-bridged phenolic phthalocyanines (H2Pc) was synthesized. These derivatives are completely new and first time reported. Four derivatives at peripheral or non-peripheral substitution on macro cyclic ring were synthesized and characterized employing various spectroscopic methods. H2Pc derivatives (defined as H2Pc-1, H2Pc-2, H2Pc-3, H2Pc-4) were immobilized on TiO2 nanoparticles to obtain photoactive nanocomposites (H2Pc/TiO2, 1% of the mass of TiO2). H2Pc derivatives were used as photosensitizer to improve the near visible-light photocatalytic efficiency of TiO2 catalyst in wastewater treatment. Photocatalytic abilities nanocomposites were tested for photocatalytic reduction of chromium (VI) ions (10 mg/L) and compared with neat TiO2. A near UV light source (365 nm) was used for illumination in a batch reactor and Cr(VI) concentration was monitored during 150 min treatment period. It is clear that H2Pc sensitized photocatalyst is effective for the reduction of chromium ions. Removal percentages were between 83.70 and 99.75% indicating almost total reduction of toxic Cr(VI) ions. Neat TiO2 was able to reduce only 55.43% of initial Cr(VI) ions. All phthalocyanine containing TiO2 composites are significantly more effective and reduce more Cr(VI) ions than TiO2 itself. Photocatalytic action of the catalysts is decreased in the following order H2Pc-4/TiO2 > H2Pc-2/TiO2 > H2Pc-1/TiO2 > H2Pc-3/TiO2. (C) 2016 The Institution of Chemical Engineers. Published by Elsevier B.V. All rights reserved.
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    Redox-Switchable New Phthalocyanines Containing Hydrazono-Thiazole-Carboxylate Fragments: Synthesis, Electrochemical, Spectroelectrochemical and Electrocolorimetric Investigation
    (Springer/Plenum Publishers, 2017) Degirmencioglu, Ismail; Er, Mustafa; Bayrak, Riza; Ozkaya, Ali Riza
    New phthalonitrile compound with Schiff base, carbothioamide and thiazole moieties as substituents and its corresponding metal-free and metallophthalocyanines (Zn(II), Ni(II), Co(II), and Cu(II)) were synthesized and characterized for the first time. The solubilities of these novel phthalocyanines were high in organic solvents. The redox properties of the compounds have been researched by cyclic voltammetry, square wave voltammetry, controlled-potential coulometry and in situ spectroelectrochemistry in dimethylsulfoxide. The compounds displayed metal and/or phthalocyanine ring-based, generally reversible or quasi-reversible reduction and oxidation processes. The effect of aggregation on the redox behavior of these complexes was also discussed. In general, decreased intensity and broadening in the main Q absorption band and the appearance of a new blue-shifted band confirmed the presence of H-type aggregates in the solutions of the complexes 4, 6 and 8 in DMSO/TBAP. The color changes associated with the redox processes and electrogenerated anionic and cationic redox species were also recorded with in situ electrocolorimetric measurements. In situ UV-vis spectral and associated color changes monitored during the reduction processes of the complexes suggested their applicability in the fields of the electrochemical technologies.
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    Substituted phthalocyanines and their electropolymerization properties
    (Elsevier Science Sa, 2016) Bayrak, Riza; Akcay, Hakki Turker; Biyiklioglu, Zekeriya; Degirmencioglu, Ismail
    In this study, new metal-free and metallo-phthalocyanine complexes (Co, TiO) were synthesized using a piperazine-substituted phthalonitrile derivative. All proposed structures were supported by instrumental methods. Electrochemical studies of H-2-Pc, (TiOPc)-O-IV, and (COPc)-Pc-II were examined using cyclic voltammetry (CV) and square-wave voltammetry (SWV) techniques. Voltammetric analyses of phthalocyanines supported the proposed structure of the synthesized complexes. All studied phthalocyanines were oxidatively electropolymerized on the working electrode during the repetitive anodic potential scans. (C) 2016 Elsevier B.V. All rights reserved.
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    Synthesis and electrochemical characterization of tetra-(5-chloro-2-(2,4-dichlorophenoxy)phenol) substituted Ni(II), Fe(II) and Cu(II) metallophthalocyanines
    (Elsevier Science Sa, 2016) Demirbas, Umit; Kobak, Rabia Zeynep Uslu; Barut, Burak; Bayrak, Riza; Koca, Atif; Kantekin, Halit
    The synthesis and characterization of novel nitrile compound (3) and peripherally tetra 5-chloro-2-(2,4-dichlorophenoxy)phenol substituted nickel(II) (4), iron(II) (5) and copper(II) (6) phthalocyanines were accomplished for the first time in this study. Electrochemical characterizations of the complexes were carried out with voltammetric and in situ spectroelectrochemical measurements. CuPc and NiPc showed common Pc based electron transfer reactions. Small potential differences were observed between the redox responses of these complexes due to the different effective nuclear charges of the metal centers. [Cl1--(FePc2-)-Pc-III] complex gave metal and Pc based electron transfer reactions. While [Cl-1-Fe(III)pc(2-)] reduced to [Cl1--(FePc2-)-Pc-II](1-), [Cl1--(FePc2-)-Pc-I](2-), and [Cl1--(FePc3-)-Pc-I](3-) during reduction reactions, a metal based ([Cl1--(FePc2-)-Pc-III]/[Cl1--(FePc2-)-Pc-IV](1+)) and then a Pc based ([Cl1--(FePc2-)-Pc-IV](1+)/[Cl1--(FePc1-)-Pc-IV](2+)) oxidation reaction was observed the cathodic potential scans. Determination of the spectra, color of the electrogenerated MPc species and peak assignments of the complexes were determinated with in situ spectroelectrochemical measurements. (C) 2016 Elsevier B.V. All rights reserved.
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    Synthesis and Spectro-Electrochemical Properties of New Metallophthalocyanines Having High Electron Transfer Capability
    (Elsevier, 2021) Bayrak, Riza; Atasen, Secil Kirlangic; Yilmaz, Ismail; Yalcin, Izzet; Erman, Murat; Unver, Yasemin; Degirmencioglu, Ismail
    It is important to synthesis and examine the redox properties of phthalocyanines and related macrocycles in order to reveal their possible applications. In this paper, new Zn2+, Co2+ and Mn2+ phthalocyanine complexes containing substituted 1,2,4-triazole groups on peripheral positions have been prepared and characterized by classical methods and electrochemistry in detail. The use of triethylamine and acetone combination in the synthesis of nitrile structures 3a and 3b , the starting compounds for phthalocyanines, both increased yield of products and shortened reaction time compared to classical synthesis of nitrile structures. The electron transfer capability of new metallophthalocyanines (ZnPcs, CoPcs and MnPcs) was investigated in detail via cyclic voltammetry (CV), square wave voltammetry (SWV) and in situ UV-vis spectroelectrochemistry. For ZnPcs, these experiments demonstrated that the complexes exhibited three well-defined reductions and two oxidations waves based on the Pc ring electroinactive nature of the Zn metal coordinated to the macrocycle. For CoPcs showed three reductions and one oxidation based on both the Pc ring and electroactive nature of Co center. Furthermore, MnPcs displayed three well-defined reductions and two oxidations waves based on either the Pc ring or electroactive Mn center. (C) 2020 Elsevier B.V. All rights reserved.
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    Synthesis of axially disubstituted silicon phthalocyanines and investigation of photodynamic effects on HCT-116 colorectal cancer cell line
    (Elsevier, 2018) Sari, Ceren; Eyupoglu, Figen Celep; Degirmencioglu, Ismail; Bayrak, Riza
    Photodynamic therapy is one of the hot topics in cancer studies. Photosensitizing chemical substrates are stimulated by light having a specific wavelength to cause fatal effect on different kinds of targets. In this study, axially 4-{[(1E)-2-furylmethylene]aminol}phenol, 4-{[(1E)-2-thienylmethylene]aminol}phenol and 4-{[(1E)-(4-nitro-2-thienyl)methylene]amino}phenol disubstituted silicon phthalocyanines were synthesized as Photosensitizers for photodynamic therapy in cancer treatment. The structural characterizations of these novel compounds were performed by a combination of FT-IR, H-1-NMR, UV-vis and mass. All these newly prepared compounds did not show aggregation at the concentration range of 2 x 10(-6) - 12 x 10(-6) M in tetrahydrofurane and also did not show aggregation in different organic solvents at 2 x 10(-6) M concentration. Phthalocyanines synthesized in this study were tested on HCT-116 colorectal cancer cells and stimulated by light has wavelength of 680 nm. The toxic effects on cancer cells which are caused by different concentrations of photosensitizing molecules have been examined and compared with the toxic effects on cancer cells that were kept in the dark. It is confirmed that these molecules caused toxic effects on colorectal cancer cells when they were stimulated by light but there was no toxic effect in the dark.
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    Synthesis of some new Methoxy Bridged Benzimidazolyl-Substituted phthalocyanines as potent inhibitors of urease
    (Elsevier Science Sa, 2018) Demirbas, Umit; Mentese, Emre; Sokmen, Bahar Bilgin; Bayrak, Riza; Akcay, Hakki Turker
    In this study, the novel peripherally 4-[(2-methyl-1H-benzimidazol-1-yl)methoxy] substituted Zn(II) (3) Cu(II) (4), Co(II) (5) phthalocyanines were prepared and their structures were characterized spectro-scopically. The light absorption behaviors of the synthesized compounds (3-6) were studied by UV-Vis spectroscopy in the different concentration and different solvents were studied also. In addition, the urease inhibition activities of the synthesized compounds were also investigated. Among the synthesized molecules, compound 5 showed the best inhibitory effect against jack bean urease with IC50 values of 0.0034 +/- 0.0010 mu M. (C) 2018 Elsevier B.V. All rights reserved.
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    Synthesis, aggregation and spectroscopic studies of novel water soluble metal free, zinc, copper and magnesium phthalocyanines and investigation of their anti-bacterial properties
    (Pergamon-Elsevier Science Ltd, 2014) Bayrak, Riza; Akcay, Hakki Turker; Beris, Fatih Saban; Sahin, Ertan; Bayrak, Hacer; Demirbas, Umit
    In this study, novel phthalonitrile derivative (3) was synthesized by the reaction between 4-nitrophthalonitrile (2) and a triazole derivative (1) containing pyridine moiety. Crystal structure of compound (3) was characterized by X-ray diffraction. New metal free and metallo-phthalocyanine complexes (Zn, Cu, and Mg) were synthesized using the phthalonitrile derivative (3). Cationic derivatives of these phthalocyanines (5, 7, 9, and 11) were prepared from the non-ionic phthalocyanines (4, 6, 8, and 10). All proposed structures were supported by instrumental methods. The aggregation behaviors of the phthalocyanines (4-11) were investigated in different solvents such as dimethylsulfoxide (DMSO), N,N-dimethylformamide (DMF), chloroform and water. Water soluble cationic Pcs (5, 7, 9, and 11) aggregated in water and sodium dodecyl sulfate was used to prevent the aggregation. The second derivatives of the UV-Vis spectra of aggregated Pcs were used for analyzing the Q and B bands of aggregated species. Thermal behaviors of the phthalocyanines were also studied. In addition, anti-bacterial properties of the phthalocyanines were investigated. We used four gram negative and two gram positive bacteria to determine antibacterial activity of these compounds. Compound 7 has the best activity against the all bacteria with 125 mu g/mL of MIC value. Compounds 4, 6, and 10 have the similar effect on the bacteria with 250 mu g/mL of MIC value. (C) 2014 Elsevier B.V. All rights reserved.
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    Synthesis, characterization and investigation of electrochemical and spectroelectrochemical properties of peripherally and non-peripherally tetra 2-methyl-5-benzothiazole substituted nickel(II), copper(II) and cobalt(II) phthalocyanines
    (Elsevier Science Sa, 2017) Demirbas, Umit; Akyuz, Duygu; Bayrak, Riza; Barut, Burak; Koca, Atif; Kantekin, Halit; Degirmencioglu, Ismail
    In this study novel tetra 2-methyl-5-benzothiazole substituted peripherally nickel(II) (6), copper(II) (8), cobalt(II) (10) and non-peripherally nickel(II) (7), copper(II) (9), cobalt(II) (11) phthalocyanines were synthesized. These novel compounds were characterized by a combination of FT-IR, H-1 NMR and UVvis and MALDI-TOF mass spectroscopic techniques. Electrochemical measurements gave well illustrated redox responses for the Pc ring and/or metal center of the complexes. While MPc bearing redox inactive metal centers underwent [(MPc-2)-Pc-II]/[(MPc-3)-Pc-II](1-), [(MPc-3)-Pc-II](1-)/[M(II)Pc(-)4](2-), [(MPc-4)-Pc-II](2-)/[(MPc-5)-Pc-II](3-) and [(MPc-2)-Pc-II](1-)/[(MPc-1)-Pc-II](1+) redox couples. (CoPc)-Pc-II illustrated [(CoPc-2)-Pc-II]/[(CoPc-2)-Pc-I](1-), [(CoPc-2)-Pc-I](1-)/[(CoPc-3)-Pc-I](2-), [(CoPc-3)-Pc-I](2-)/[(CoPc-4)-Pc-I](3-) and [(CoPc-2)-Pc-II]/[(CoPc-2)-Pc-II](1+) redox couples respectively during reduction and oxidation processes respectively. Position of the substituents altered the chemical and electrochemical reversibility of the redox processes. While the substituents were non-peripheral position, the complexes aggregated and both of the redox processes of the aggregated and nonaggregated species were observed, incorporation of the substituents to peripheral position decreased aggregations of the complexes, therefore MPcs substituted at peripheral positions illustrated well resolved reversible redox reactions. In situ spectroelectrochemical results illustrated that electrogenerated MPc species had distinct color differences.
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    Synthesis, Characterization and Investigation of Electrochemical and Spectroelectrochemical Properties of Peripherally Tetra Diethoxypropan Substituted Phthalocyanines
    (Wiley-V C H Verlag Gmbh, 2021) Akyuz, Duygu; Akcay, Hakki Turker; Bayrak, Riza
    In this study novel peripherally tetra 1,3-diethoxy-2-propanol substituted Co(II), Cu(II), Mg(II), Ni(II) Zn(II) phthalocyanine derivatives were prepared. The characterization of the novel compounds was made by FT-IR,H-1-NMR, UV-vis and MALDI-TOF mass. Electrochemical,in-situspectroelectrochemical and electrocolorimetric measurements have been carried out with the aim to determine the redox properties, to illuminate reaction mechanism and the effect of substituent and metal center. Moreover, the color properties and aggregation tendency of compounds were also investigated.
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    The determination of photophysical and photochemical parameters of novel metal-free, zinc(II) and lead(II) phthalocyanines bearing 1,2,4-triazole groups
    (Elsevier Science Sa, 2016) Demirbas, Umit; Piskin, Mehmet; Bayrak, Riza; Unluer, Dilek; Dugdu, Esra; Durmus, Mahmut; Kantekin, Halit
    In this study the synthesis and characterization of novel phthalonitrile compound (3) and its metal-free (4), zinc(II) (5), and lead(II) (6) phthalocyanines bearing four 4-(4-methoxyphenylethyl)-5-propyl-2,4-dihydro-3H-1,2,4-triazol-3-one groups at peripheral positions were synthesized for the first time. These novel compounds were fully characterized by FT-FT-IR, H-1 NMR, UV-vis and MALDI-TOF mass spectroscopic techniques. Their photochemical and photophysical properties were also investigated in N, N-dimethylformamide solutions. In addition, the effect of 4(4-methoxyphenylethyl)-5-propyl-2,4dihydro-3H-1,2,4-triazol-3-one groups as substituents and central metal ions (without metal, zinc(II) or lead(II)) in the phthalocyanine cavity on these properties were also compared. The studied zinc(II) or lead (II) phthalocyanines can be potential Type II photosensitizers for photodynamic therapy in cancer applications because these phthalocyanines showed good singlet oxygen generation and appropriate photodegradation. (C) 2016 Elsevier B.V. All rights reserved.
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    Use of azomethine-bridged phenolic metallophthalocyanines for sensitization of TiO2
    (Desalination Publ, 2017) Koc Kesir, Melek; Albay, Cansu; Altin, Ilknur; Bayrak, Riza; Gokce, Halil; Degirmencioglu, Ismail; Sokmen, Munevver
    A group of novel azomethine-bridged phenolic metallophtalocyanines (substituted at -nonperipheral position, MPc) were synthesized, characterized and used as sensitizer. Phthalocyanine derivatives (containing TiO(II), Fe(II), Co(II), Ni(II) and Zn(II) ions in the center of phtalocyanine) were immobilized on TiO2 photocatalyst using a wet deposition method. MPc/TiO2 nanocomposites have been tested for their photocatalytic reduction ability of Cr(VI) ions in aqueous solution under near visible light irradiation. The results demonstrated that the presence of the sensitizer is certainly beneficial for the photocatalytic activity of TiO2, confirming the significant role of substitution and metal-co-ordination in the center of the phthalocyanine ring. Photoreduction results show that the all composite materials exposed significantly higher Cr(VI) removal performance than bare TiO2-Consequently, MPc sensitized TiO2 nanocomposites may be good alternatives for efficient photocatalysis that can be used for wastewater treatment processes.