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Öğe 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.Öğe Computational studies on the anastrozole and letrozole, effective chemotherapy drugs against breast cancer(Pergamon-Elsevier Science Ltd, 2014) Akcay, Hakki Turker; Bayrak, RizaIn 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.Öğe Novel triazole substituted phthalocyanines showing high singlet oxygen quantum yields(Elsevier, 2019) Demirbas, Umit; Bayrak, Riza; Dilber, Gulsev; Mentese, Emre; Akcay, Hakki TurkerIn 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.Öğe Production and characterization of activated carbon foams with various activation agents for electrochemical double layer capacitors (EDLCs) applications(Elsevier, 2024) Ozcifci, Zehra; Emirik, Mustafa; Akcay, Hakki Turker; Yumak, TugrulSucrose-based activated carbons were obtained by carbon foams with sugar and cobalt (II) nitrate as precursors, followed by using different chemical activation agents. The effect of Co(NO3)2 concentration, the carbonization temperature and the activation agent on the surface chemistry, porosity were investigated. Textural characterization and electrochemical tests were performed on the activated carbon samples (CF). The results showed that the activated carbon produced by H2SO4 and KOH at 800 degrees C had a surface area of 691 m2/g and 1125 m2/g, 89% and 80% of the sample pore structure was microporous, and specific capacitance of 8.4 F/g and 162.2 F/g at a constant current density of 250 mA/g, respectively. K2CO3-activated carbon had 918 m2/g surface area and 63% of the sample pore structure with microporous and 1.4 F/g specific capacitance, H3PO4-activated carbon and ZnCl2-activated carbon had 1833 m2/g and 1597 m2/g surface area, 53% mesoporous and 50% mesoporous, 222.4 F/g and 149.9 F/g specific capacitance respectively. The most promosing result was observed in the electrochemical storage behavior of the carbon materials with hierarchical pore structure activated with H3PO4 is associated with increasing defect zones at the edges of micro- and mesoporous morphology, resulting in a higher surface area and increased conductivity of the material.Öğe Substituted phthalocyanines and their electropolymerization properties(Elsevier Science Sa, 2016) Bayrak, Riza; Akcay, Hakki Turker; Biyiklioglu, Zekeriya; Degirmencioglu, IsmailIn 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.Öğe Sucrose-based activated carbon foams as an electrode active material for supercapacitors(Springer, 2023) Ozcifci, Zehra; Ozsanli, Mehmet Ali; Akcay, Hakki Turker; Yumak, TugrulActivated carbon foams (ACFs) have been successfully prepared by foaming sucrose with Zn nitrate and further chemical activation with H3PO4. The effect of the foaming agent (Zn) concentration and the activation temperature on the surface chemistry, porosity, and morphology were investigated. The ACFs reveal high specific surface area, non-uniform variable porous structure, and high oxygen content. The ACFs represent high specific capacitance and very low equivalent serial resistance (ESR) values as electrode material. The ACF obtained at 600 degrees C has a specific capacitance of 205.4 F/g at 1 A/g constant current density. The pseudocapacitive contribution of oxygen-containing surface functional groups was proved by CV curves at slow scan rates. The high performance of the ACFs may be attributed not only to the high surface area, and hetero-atom-containing SGFs but also to the unique surface morphology which originated from the release of gaseous products during the foaming process.Öğe 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 TurkerIn 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.Öğe 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, UmitIn 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.Öğe 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, RizaIn 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.Öğe Treatment of wastewater containing organic pollutants in the presence of N-doped graphitic carbon and Co3O4/peroxymonosulfate(Springer Japan Kk, 2023) Akcay, Hakki Turker; Demir, Adem; Ozcifci, Zehra; Yumak, Tugrul; Keles, TurgutThe disposal of organic pollutants is one of the important research topics. Some of the studies in this field are based on the degradation of organic pollutants with a catalytic agent. The cobalt tetraoxide/peroxymonosulfate system is an important catalytic system used for the radical degradation of organic pollutants. To increase the catalytic efficiency of such reactions, graphitization of activated carbon used as a support solid and nitrogen doping to the carbon structure are commonly used methods. In this study, cobalt tetraoxide production, N-doping and graphitization were carried out in a single step by heat treatment of activated carbon doped with the phthlocyanine cobalt (II) complex. The catalytic performance of the catalyst/peroxymonosulfate system was investigated by changing the pH, catalyst, and PMS concentration parameters on rhodamine B and 1,3,5 trichlorophenol, which were used as models. It was seen that the catalysts had 97% activity on rhodamine B in 16 min and 100% on 1,3,5 trichlorophenol in 6 min. It was observed that the catalysts continued to show high catalytic activity for five cycles in reusability studies and had a very low cobalt leaching rate. These results are in good agreement with previously published studies. In line with these results, the synthesized N-doped graphitic carbon/Co3O4 catalyst can be used as an effective catalyst for wastewater treatments. [GRAPHICS] .
