Person: SALAN, ÜMİT
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SALAN
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ÜMİT
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Publication Metadata only Synthesis, characterization, and electrochemical and in-situ spectroelectrochemical properties of novel peripherally and non-peripherally 7-oxy-3-(3,4-dimethoxyphenyl) coumarin substituted phthalocyanines(ELSEVIER SCI LTD, 2019) ÖZKAYA, ALİ RIZA; Feridun, Seda Gureli; Orman, Efe Baturhan; Salan, Umit; Ozkaya, Ali Riza; Bulut, MustafaNovel metal-free (4 and 9), Zn(II) (5 and 10) and Co(II) (6 and 11) phthalocyanines (Pcs) bearing four 7-oxy-3(3,4-dimethoxyphenyl)coumarin (1) substituents at peripheral (13) and non-peripheral (a) positions have been prepared by cyclotetramerization reactions of 4-(3-(3,4-dimethoxyphenyl)coumarin-7-oxy)phthalonitrile (3) or 3-(3-(3,4-dimethoxy-phenyl)coumarin-7-oxy)phthalonitrile (8), respectively, in the presence of relevant metal acetate salts in N,N-dimethylaminoethanol. The compounds have been characterized by elemental analysis, FTIR, UV-Vis and MALDI-TOF mass spectroscopies. Thermal properties of the compounds were evaluated by thermogravimetric analysis and differential scanning calorimetry. Electrochemical redox properties of all compounds were investigated by voltammetric and in-situ spectroelectrochemical measurements in dimethylsulfoxide including tetrabutyl ammonium perchlorate as the supporting electrolyte. The metal-free and Zn(II)Pc compounds displayed Pc ring-based redox processes whereas both Pc ring-based and metal-based electron transfer processes were observed for Co(II)Pc complexes. H-aggregation tendency of peripherally substituted compounds was found to be much higher than that of non-peripherally substituted ones. It was observed that there have been systemmatic redox potential and aggregation behaviour differences between the peripherally and non-peripherally substituted Pc compounds. These differences were attributed to different sterical and conformational effects of these substitution patterns. In-situ spectroelectrochemical and in-situ electrocolorimetric measurements suggested that peripherally substituted Co(II)Pc is a multi-coloured chromophore material displaying distinct spectral and colour changes during the first reduction and oxidation processes, and thus, being suitable for electrochromic applications.Publication Metadata only Synthesis, characterization and electrochemical properties of tetra 7-oxy-3-biphenylcoumarin substituted metal-free, zinc(II), cobalt(II) and indium(III) phthalocyanines(ELSEVIER SCI LTD, 2016) ÖZKAYA, ALİ RIZA; Gok, Asiye; Orman, Efe Baturhan; Salan, Umit; Ozkaya, Ali Riza; Bulut, MustafaA novel coumarin, 7-hydroxy-3-biphenylcoumarin 1, was prepared by Perkin reaction of 4-biphenylacetic acid with 2,4-dihydroxybenzaldehyde in the presence of NaOAc/Ac2O. In addition, two respective phthalonitril derivatives, 7-(2,3-dicyanophenoxy)-3-biphenylcoumarin 2/7-(3,4-dicyanophenoxy)-3-biphenylcoumarin 3, were synthesized by nucleophilic aromatic substitution reactions of 3-nitro/4-nitrophthalonitrile with 7-hydroxy-3-biphenylcoumarin 1. The synthesis of corresponding novel zinc(II) phthalocyanines (Pcs) 4 and 8, cobalt(II) Pcs 5 and 9, indium(III)(Cl) Pcs 6 and 10, and metal-free Pcs 7 and 11, carrying 7-oxy-3-biphenylcoumarins in the non-periphery/periphery was performed by cyclotetramerization of compounds 2 or 3. The novel chromogenic coumarin 1, phthalonitriles (2 and 3) and Pcs (4-11) were characterized by elemental and spectroscopic analysis, including H-1 NMR, FT-IR, UV-vis spectral and MALDI-TOF mass data. The redox properties of these compounds were also investigated by voltammetry and in situ spectroelectrochemistry on Pt in dimethylsulfoxide/tetrabutylammonium perchlorate. Furthermore, the electrocatalytic performances of the compounds for the oxygen reduction reaction were also studied. (C) 2016 Elsevier Ltd. All rights reserved.Publication Metadata only Photovoltaic and electrocatalytic properties of novel ball-type phthalocyanines bridged with four dicumarol(ROYAL SOC CHEMISTRY, 2012) ÖZKAYA, ALİ RIZA; Salan, Umit; Altindal, Ahmet; Ozkaya, Ali Riza; Salih, Bekir; Bekaroglu, OzerThe new ball-type metallo bisphthalocyanines (Co2Pc2 and Zn2Pc2) were synthesized from the corresponding [4,4'-bis(dicoumaroylphthalonitrile)] which can be obtained from the reaction of 3,3'-methylenebis(4-hydroxy-2H-chromen-2-one) and 4-nitrophthalonitrile. The structures of the newly synthesized compounds have been confirmed and characterized by elemental analysis, UV/Vis, IR and H-1 NMR spectroscopies and MALDI-TOF mass spectrometry. Solar cells of the configuration ITO/Co2Pc2/C60/Al and ITO/Zn2Pc2/C60/Al were fabricated. The effect of the thickness of the active Pc layer - the thickness of the Pc layer was varied from 15 to 80 nm - on solar cells parameters has been investigated. A nearly thickness independent open circuit voltage was observed in both structures. The maximum photovoltaic conversion efficiency, short circuit current and fill factor were observed in ITO/Zn2Pc2/C60/Al cell with 80 nm Pc layer to be 0.255%, 1 mA cm(-2) and 0.38, respectively. The redox properties of the ball-type complexes were investigated by cyclic voltammetry, controlled-potential coulometry and in situ spectroelectrochemistry in DMSO-TBAP. The electrochemical measurements showed that the complexes form ring-based and/or metal-based mixed-valence species, due to the remarkable intramolecular interactions between the two metal phthalocyanine units. The Vulcan XC-72 (VC)/Nafion(Nf)/Co2Pc2 modified glassy carbon electrode showed much higher catalytic performance towards oxygen reduction, compared to the VC/Nf/Zn2Pc2 modified one. It was found that the VC/Nf/Co2Pc2 catalyst is nearly insensitive to the presence of methanol. In the presence of 1 M methanol in the electrolyte, the catalytic performance of the Co2Pc2-based catalyst in oxygen reduction was much better than that of the Pt-based one. Thus, it was shown that the VC/Nf/Co2Pc2 catalyst can be a good alternative to VC/Nf/Pt as a cathode catalyst in direct methanol fuel cells.