Showing papers by "Atıf Koca published in 2010"
TL;DR: In this article, the synthesis of metal-free and metallophthalocyanines [Ni(II, Zn(II), Co(II) and Cu(II)] were prepared by cyclotetramerization of a novel 4-{2]-2-(1-naphthyloxy)ethoxy]ethoxy}phthalonitrile and the corresponding metal salts (NiCl2,Zn(CH3COO)2, CoCl2 and CuCl2).
46 citations
TL;DR: The stable uranyl complexes, [UO(2)(L)C(9)H(19)OH], were obtained from 3,5-dichlorosalicyl-(L(I)) and salicyl-aldehyde-S-propyl-thiosemicarbazones (L(II) with substituted-salicylaldehyde in nonyl alcohol, which are important factors in controlling the redox properties.
Abstract: The stable uranyl complexes, [UO2(L)C9H19OH], were obtained from 3,5-dichlorosalicyl-(LI) and salicyl-aldehyde-S-propyl-thiosemicarbazones (LII) with substituted-salicylaldehyde in nonyl alcohol. The structures of the complexes have been characterized by elemental analysis, IR, 1H NMR, conductivity, magnetic moment measurements, cyclic voltammetry, thermal gravimetric analysis and single crystal X-ray diffraction technique. The U(VI) centre is seven-coordinated in a distorted pentagonal bipyramidal geometry. The relative orientations of the nonyl alcohol and S-propyl group in the title complexes are completely different due to different crystal packing. Electrochemical behaviors of the thiosemicarbazone ligands and the uranyl complexes were studied using cyclic voltammetry and square wave voltammetry. Redox processes of the compounds are significantly influenced by the central metal ions and the nature of substituents on the thiosemicarbazones, which are important factors in controlling the redox properties. In situ spectroelectrochemical studies were employed to determine the colors and spectra of electro-generated species of the complexes.
37 citations
TL;DR: In this paper, peripherally 3 and 4-substituted functionalized ionophore ligands (1, 3 ) and their α-and β-tetra polyalcohol substituted lead(II) phthalocyanines M{Pc[S−CH(C 3 H 7 )(C 2 H 5 OH)] 4 } (7, 9 and 11 ) and M{S−C 6 H 12 (OH)] 4 }, which are a mixture of different isomers.
35 citations
TL;DR: The tetra substituted metallophthalocyanines as mentioned in this paper were synthesized from the corresponding phthalodinitrile 1 and divalent metal salts at 170°C in fused state.
33 citations
TL;DR: In this article, neutral dioxomolybdenum(VI) complexes of dibasic 2-hydroxy-1-naphthaldehyde S-ethyl-4-H/phenyl-thiosemicarbazones (H: L1, C6H5: L2) have been synthesized.
31 citations
TL;DR: In this paper, metal free (2), manganese (3), and cobalt (4) phthalocyanines, which are octa-substituted at the peripheral positions with [4-(thiophen-3-yl)-phenoxy] moieties, were synthesized and electrochemical properties were reported for the first time.
31 citations
TL;DR: In this paper, the effects of the number of fluoro substituents to the electrochemical, in situ spectroelectrochemical, and electrocatalytic activities of metallophthalocyanines for the hydrogen evolution reaction were described.
Abstract: This study describes the effects of the number of fluoro substituents to the electrochemical, in situ spectroelectrochemical, and electrocatalytic activities of metallophthalocyanines for the hydrogen evolution reaction Tuning of the number of fluoro groups shifts the redox processes and affects the aggregation tendencies of the complexes An in situ electrocolorimetric method was applied to investigate the color of the electrogenerated anionic and cationic forms of the complexes Cobalt phthalocyanines incorporated into Nafion film on a glassy carbon electrode decreases the overpotential of the working electrode for H+ reduction The number and position of the electron withdrawing substituents and nature of the metal center change the electrocatalytic activities for the hydrogen evolution reaction in aqueous solutions
28 citations
TL;DR: In this paper, aryloxy-and alkylalkyloxy-substituted pyrazine dicarbonitriles were synthesized from 5,6-dichloropyrazine-2,3-dicarbonitrile and corresponding phenol/alcohol derivatives.
24 citations
TL;DR: In this article, the electrochemical, in situ spectroelectrochemical, electrocolorimetric and electrocatalytic characterization of metallophthalocyanines bearing four dioctylaminocarbonyl biphenyloxy groups (MPc's) was described.
Abstract: This study describes the electrochemical, in situ spectroelectrochemical, in situ electrocolorimetric and electrocatalytic characterization of metallophthalocyanines bearing four dioctylaminocarbonyl biphenyloxy groups (MPc's). While CoPc gives both metal-based and ring-based redox processes, ZnPc and CuPc show only ring-based reduction and oxidation processes. In-situ electrocolorimetric method was applied to investigate color of the electrogenerated anionic and cationic forms of the complexes. Perchloric acid titrations monitored by cyclic voltammetry and spectrophotometry represent possible electrocatalytic activities of the complexes for hydrogen evolution reaction. CuPc having inactive metal center incorporated into a Nafion film on GCE decreases overpotential of the electrode for H(+) reduction in aqueous Solution.
21 citations
TL;DR: In this article, the synthesis, spectroscopic and electrochemical properties of new phthalocyanines bearing four morpholine and four chloro units are reported, and two-step synthesis involved efficient nucleophilic substitution of 4,5-dichlorophthalonitrile as the key step.
Abstract: The synthesis, spectroscopic and electrochemical properties of new phthalocyanines bearing four morpholine and four chloro units is reported. Two-step synthesis involved efficient nucleophilic substitution of 4,5-dichlorophthalonitrile as the key step. The free-base phthalocyanine and its several complexes have been characterized using UV-vis, IR, 1HNMR, 13CNMR and mass spectroscopic data. Voltammetric and spectroelectrochemical studies show that while cobalt phthalocyanine gives both metal- and ring-based, diffusion-controlled, multi-electron and reversible/quasi-reversible redox processes, other complexes give ring-based, multi-electron and reversible/quasi-reversible redox processes.
15 citations
TL;DR: In this article, the basic principles of spectroscopic and electroanalytical techniques and their use in determining material properties are covered in some detail in many undergraduate chemistry programs, but there are limited examples of laboratory experiments with in situ instrumental techniques for technological applications in the real world.
Abstract: This experiment employs current technology to enhance and extend existing lab content. The basic principles of spectroscopic and electroanalytical techniques and their use in determining material properties are covered in some detail in many undergraduate chemistry programs. However, there are limited examples of laboratory experiments with in situ instrumental techniques for technological applications in the real world. Thus, we introduce two examples of more recent in situ experimental methodology: in situ spectroelectrochemical and in situ electrocolorimetric methods. This experiment introduces students to (i) electrochromism methodology, (ii) thin-film preparation techniques of electrochromic materials, (iii) application of in situ spectroelectrochemical and in situ electrocolorimetric techniques to monitor electrochromism, (iv) design of an electrochromic display device, (v) demonstration of electrochemical writing with an electrochromic display device, and (vi) usage of an in situ electrocolorimetri...