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2014

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Articles 11221 - 11250 of 12299

Full-Text Articles in Physical Sciences and Mathematics

Rosmarinic Acid: A Potent Carbonic Anhydrase Isoenzymes Inhibitor, Meryem Topal, İlhami̇ Gülçi̇n Jan 2014

Rosmarinic Acid: A Potent Carbonic Anhydrase Isoenzymes Inhibitor, Meryem Topal, İlhami̇ Gülçi̇n

Turkish Journal of Chemistry

Rosmarinic acid is a water-soluble ester of caffeic acid and 3,4-dihydroxyphenyllactic acids, and is mainly found in plant species including Boraginaceae and Lamiaceae. In this research, we determined the inhibition property of rosmarinic acid on carbonic anhydrase isoenzymes I and II (hCA I and II) purified from human erythrocytes by using Sepharose-4B affinity column chromatography. hCA I and II isoenzymes were obtained with a yield of 57.9% and 67.2% and 76.5- and 509.3-fold purification of each isoenzyme, respectively. In order to show the purity of the isoenzymes, SDS-PAGE was performed and one band was observed. In vitro inhibition of both …

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History, Development, And A New Concept Of Phthalocyanines In Turkey, Özer Bekaroğlu Jan 2014

History, Development, And A New Concept Of Phthalocyanines In Turkey, Özer Bekaroğlu

Turkish Journal of Chemistry

This paper reviews the history of phthalocyanines in Turkey. Phthalocyanines are chemical compounds that were accidently discovered nearly a century ago. The relevant research and articles have grown dramatically in Turkey since our first paper on them containing four [15]crown[5] published in 1986. The ball-type phthalocyanines were produced and published as a new concept in phthalocyanine chemistry for the first time by our group in Turkey in 2006. Unfortunately, with the exception of our work on this subject, almost no papers have been published in Turkey or in other countries since then. We strongly urge scientists to consider working on …

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N-Bridged Dimers Of Tetrapyrroles Complexed By Transition Metals: Syntheses, Characterization Methods, And Uses As Oxidation Catalysts, Ümi̇t İşci̇, Fabienne Dumoulin, Alexander B. Soroki̇n, Vefa Ahsen Jan 2014

N-Bridged Dimers Of Tetrapyrroles Complexed By Transition Metals: Syntheses, Characterization Methods, And Uses As Oxidation Catalysts, Ümi̇t İşci̇, Fabienne Dumoulin, Alexander B. Soroki̇n, Vefa Ahsen

Turkish Journal of Chemistry

N-bridged dimers of tetrapyrroles complexed by transition metals have been known for nearly four decades, and gained renewed attention when their powerful oxidation properties were recently evidenced. This article is a state of the art review of the reported complexes and of their synthetic methods. Beyond classical chemistry characterization tools, specific methods appropriate to their structure are used and are presented in detail. Finally, their uses and importance of oxidation catalysts are reviewed.

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Boron-Containing Tetrapyrroles, Şennur Özçeli̇k, Ahmet Gül Jan 2014

Boron-Containing Tetrapyrroles, Şennur Özçeli̇k, Ahmet Gül

Turkish Journal of Chemistry

The recent advances in the synthesis of carborane and boronic ester-substituted tetrapyrroles (porphyrins, porphyrazines, and phthalocyanines) are reviewed together with their possible utilization as agents for photodynamic therapy (PDT) and boron neutron capture therapy of cancer (BNCT) as well as dual PDT/BNCT sensitizers.

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Effect Of The Anchoring Group In Porphyrin Sensitizers: Phosphonate Versus Carboxylate Linkages, Christine Stern, Alla Bessmertnykh Lemeune, Yulia Gorbunova, Aslan Tsivadze, Roger Guilard Jan 2014

Effect Of The Anchoring Group In Porphyrin Sensitizers: Phosphonate Versus Carboxylate Linkages, Christine Stern, Alla Bessmertnykh Lemeune, Yulia Gorbunova, Aslan Tsivadze, Roger Guilard

Turkish Journal of Chemistry

Porphyrins are an important family of organic chromophores that have attracted attention as photosensitizers in TiO_2-based dye-sensitized solar cells (DSSCs). This brief review is dedicated to comparative studies of phosphonic and carboxylic acid anchoring groups for attachment of porphyrin sensitizers on semiconductors or conductors surface. Here we have selected some representative examples of recently described phosphonate/carboxylate porphyrins with the aim to demonstrate that porphyrin phosphonate should be a promising anchoring group for such systems.

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Electrochemistry Of Fe(Iv) And Mn(Iv) Corroles Containing Meso-Dichlorophenyl Substituents And The Use Of These Compounds As Catalysts For The Electroreduction Of Dioxygen In Acid Media, Lina Ye, Zhongping Ou, Deying Meng, Mingzhu Yuan, Yuanyuan Fang, Karl M. Kadish Jan 2014

Electrochemistry Of Fe(Iv) And Mn(Iv) Corroles Containing Meso-Dichlorophenyl Substituents And The Use Of These Compounds As Catalysts For The Electroreduction Of Dioxygen In Acid Media, Lina Ye, Zhongping Ou, Deying Meng, Mingzhu Yuan, Yuanyuan Fang, Karl M. Kadish

Turkish Journal of Chemistry

Two meso-dichlorophenyl substituted metallocorroles were synthesized and characterized as to their electrochemical and spectroelectrochemical properties in dichloromethane, benzonitrile, and pyridine containing 0.1 M tetra-n-butylammonium perchlorate (TBAP) as supporting electrolyte. The examined compounds are represented as (Cl_2Ph)_3CorFe^{IV}Cl and (Cl_2Ph)_3CorMn^{IV}Cl where (Cl_2Ph)_3Cor is the trianion of 5,10,15-tri(2,4-dichlorophenyl)corrole. Each metallocorrole was examined as to its catalytic activity for the electoreduction of dioxygen when coated on an edge-plane pyrolytic graphite electrode in 1.0 M HClO_4. Cyclic voltammetry combined with linear sweep voltammetry at a rotating disk electrode (RDE) and a rotating ring disk electrode (RRDE) was utilized to evaluate the catalytic activity for the …

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Encapsulation Of Phthalocyanine-C_{60} Fullerene Conjugates Into Metallosupramolecular Subphthalocyanine Capsules: A Turn Of The Screw, Irene Sanchez-Molina, Mine Ince, Giovanni Bottari, Christian Georges Claessens, Maia Victoria Martinez Diaz, Tomas Torres Jan 2014

Encapsulation Of Phthalocyanine-C_{60} Fullerene Conjugates Into Metallosupramolecular Subphthalocyanine Capsules: A Turn Of The Screw, Irene Sanchez-Molina, Mine Ince, Giovanni Bottari, Christian Georges Claessens, Maia Victoria Martinez Diaz, Tomas Torres

Turkish Journal of Chemistry

In this communication, encapsulation studies between metallosupramolecular capsule 1, formed by 2 subphthalocyanines (SubPcs) coordinated to 3 metallic centers, and phthalocyanine (Pc)-C_{60} fullerene conjugates 2--5 have been carried out. It was shown that the encapsulation of the C_{60} moiety by the SubPc cage occurred exclusively for dyads 2--4, whereas it was not observed in the case of triad 5. The rigidity of the linker between the Pc and the fullerene unit proved to have an important impact in the complex formation. Complex formation was tested in 2 different solvents, where the importance of solvophobic effects was highlighted. The resulting multicomponent …

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Td-Dft Calculations And Mcd Spectroscopy Of Porphyrin And Phthalocyanine Analogues: Rational Design Of Photosensitizers For Pdt And Nir Region Sensor Applications, John Mack, Martijn Wildervanck, Tebello Nyokong Jan 2014

Td-Dft Calculations And Mcd Spectroscopy Of Porphyrin And Phthalocyanine Analogues: Rational Design Of Photosensitizers For Pdt And Nir Region Sensor Applications, John Mack, Martijn Wildervanck, Tebello Nyokong

Turkish Journal of Chemistry

Geometry optimizations and TD-DFT calculations have been carried out on series of fused-ring-expanded phthalonitriles, phthalocyanines, and aza-dipyrromethene boron difluoride (aza-BODIPY) dyes and trends in their optical and redox properties have been analyzed. The potential utility of fused-ring-expanded phthalocyanine and aza-BODIPY analogues for photodynamic therapy and near infrared region sensor applications is assessed on this basis. Recent attempts to prepare fused-ring-expanded aza-BODIPY analogues with benzene, pyrazine, and naphthalene rings have demonstrated that the properties of aza-BODIPYs vary markedly when different fused ring systems are added to the \beta-carbons of the pyrrole rings. A comparison of the TD-DFT calculations demonstrates that, as …

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Coupling Ferrocene To Brominated Tetraazaporphyrin: Exploring An Alternative Synthetic Pathway For Preparation Of Ferrocene-Containing Tetraazaporphyrins, Victor N. Nemykin, Elena A. Makarova, Nathan R. Erickson, Pavlo V. Solntsev Jan 2014

Coupling Ferrocene To Brominated Tetraazaporphyrin: Exploring An Alternative Synthetic Pathway For Preparation Of Ferrocene-Containing Tetraazaporphyrins, Victor N. Nemykin, Elena A. Makarova, Nathan R. Erickson, Pavlo V. Solntsev

Turkish Journal of Chemistry

A Castro--Stephens coupling reaction between metal-free 3(2),8(7)-dibromo- 2(3),7(8),12(13),17(18)-tetra-tert-butyl-5,10,15,20-tetraazaporphyrin and (ferrocenylethynyl)copper resulted in the formation of copper 2(3),7(8),12(13), 17(18)-tetra-tert-butyl-3(2), 8(7)-di(ferrocenylethynyl)-5,10,15,20-tetraazaporphyrin and copper 2(3),7(8),12(13),17(18)-tetra-tert-butyl-3(2)-ferrocenylethynyl-5, 10,15,20-tetraazaporphyrin, which were separated in the form of 2 positional isomers along with copper 3(2)-bromo-2(3),7(8),12(13),17(18)-tetra-tert-butyl-5,10,15,20-tetraazaporphyrin and copper 2(3),7(8),12(13),17(18)-tetra-tert-butyl-5,10,15,20-tetraazaporphyrin. A similar reaction with metal-free 3(2),8(7),13(12), 18(17)-tetrabromo-2(3),7(8),12(13),17(18)-tetra-tert-butyl-5,10,15,20-tetraazaporphyrin resulted in only a trace amount of 3(2),8(7),13(12)-tribromo-2(3),7(8),12(13),17(18)-tetra-tert-butyl-18(17) -ferrocenylethynyl-5,10,15,20-tetraazaporphyrin, while no products with larger number of organometallic substituents were observed. Direct coupling between ferrocenelithium and 3(2),8(7)-dibromo-2(3),7(8),12(13),17(18)-tetra-tert-butyl-5,10,15,20-tetraazaporphyrin resulted in a debromination reaction accompanied by very minor dimerization of the tetraazaporphyrin core, which was explained based on the steric properties of the parent tetraazaporphyrin. The …

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Nature Of Second-Order Nonlinear Optical Response In Phthalocyanine Derivatives: A Density Functional Theory Study, Chiming Wang, Chao Chen, Qingqi Zhang, Dongdong Qi, Jianzhuang Jiang Jan 2014

Nature Of Second-Order Nonlinear Optical Response In Phthalocyanine Derivatives: A Density Functional Theory Study, Chiming Wang, Chao Chen, Qingqi Zhang, Dongdong Qi, Jianzhuang Jiang

Turkish Journal of Chemistry

Density functional theory was employed to investigate a series of phthalocyanine derivatives, discovering the limitation when the expansion of the conjugated system was employed to improve the hyper-Rayleigh scattering response coefficient. Furthermore, an unusually C_{\infty v}-type octupolar population was found by electrostatic potential analysis. In addition, the dynamic and static hyper-Rayleigh scattering responses (\beta_{HRS}) were simulated using the coupled perturbed density functional theory, showing an increasing dynamic \beta_{HRS} value along with an increase in incident light energy.

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Synthesis And Characterization Of Tetra-Substituted Titanium(Iv) Phthalocyanines With Axial Ligand, Deni̇z Kutlu Tarakci, İlke Gürol Jan 2014

Synthesis And Characterization Of Tetra-Substituted Titanium(Iv) Phthalocyanines With Axial Ligand, Deni̇z Kutlu Tarakci, İlke Gürol

Turkish Journal of Chemistry

In this paper, the synthesis and characterization of peripheral tetra-2-(2-ethyloxyethyloxy)ethyloxy substituted oxo-titanium phthalocyanines (TiOPcs) are reported. The reaction of 2,2,3,3-tetrafluoropropoxy substituted and [2-(2-ethoxyethoxy)ethoxy] substituted TiOPcs (1 and 3) with 4-[(6-hydroxyhexyl)oxy]benzene-1,2-diol as a strongly chelating oxygen donor ligand is described. Compounds 1a and 3a bearing the hydroxyl group as an axial ligand of the bulky group are converted into a thiol group (1c and 3c). The new compounds are characterized by elemental analysis, FT-IR, ^1H NMR, and mass spectrometry. While the fluoropropoxy substituted TiOPc has good solubility in polar solvents such as acetone and THF, the other TiOPc is soluble in …

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Synthesis And Electrochemical And Spectroelectrochemical Characterization Of Chloromanganese(Iii) Phthalocyanines, Mukaddes Özçeşmeci̇, Ilgin Nar, Esi̇n Hamuryudan Jan 2014

Synthesis And Electrochemical And Spectroelectrochemical Characterization Of Chloromanganese(Iii) Phthalocyanines, Mukaddes Özçeşmeci̇, Ilgin Nar, Esi̇n Hamuryudan

Turkish Journal of Chemistry

The synthesis of novel, symmetrical, tetrasubstituted manganese phthalocyanine complexes bearing 4 hexylthio, 2',3',4',5',6'-pentafluorobenzyloxy, 2',3',5',6'-tetrafluoro-4'-hexylthio-benzyloxy, and 2',3',5',6'-tetrafluoro-4'-pentoxy-benzyloxy units is reported. The new compounds have been characterized by using elemental analyses and UV-Vis, FT-IR, and mass spectroscopic data. The electrochemical properties of the manganese phthalocyanine complexes were investigated by cyclic and square wave voltammetry and the nature of the observed redox processes was studied by spectroelectrochemistry.

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Diphenylethoxy-Substituted Metal-Free And Metallophthalocyanines As Potential Photosensitizer For Photodynamic Therapy: Synthesis And Photophysical And Photochemical Properties, Yusuf Yilmaz, Ali̇ Erdoğmuş, Muhammet Kasim Şener Jan 2014

Diphenylethoxy-Substituted Metal-Free And Metallophthalocyanines As Potential Photosensitizer For Photodynamic Therapy: Synthesis And Photophysical And Photochemical Properties, Yusuf Yilmaz, Ali̇ Erdoğmuş, Muhammet Kasim Şener

Turkish Journal of Chemistry

The synthesis of a 4-(2,2-diphenylethoxy)phthalonitrile (1) and its organosoluble free base (2), zinc(II) (3), nickel(II) (4), and cobalt(II) (5) phthalocyanine derivatives is presented in this work. The novel complexes were characterized by elemental analyses and spectral data such as infrared, nuclear magnetic resonance, ultraviolet visible, and mass data. General tendencies were described for photophysics (fluorescence) and photochemistry (photodegradation and singlet oxygen quantum yields) of the free base and zinc(II) phthalocyanine derivatives in dimethylformamide. The quantum yield values of fluorescence (\Phi_F), singlet oxygen formation (\Phi_{\Delta}), and photodegradation (\Phi_d) for the zinc phthalocyanine were found to be 0.37, 0.48, and 9.12 \times …

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Synthesis, Characterization, And Photophysical And Photochemical Properties Of 3-(4-Phenyloxy)Coumarin Containing Metallo- And Metal-Free Phthalocyanines, Nurullah Kartaloğlu, Ali̇ye Asli Esenpinar, Mustafa Bulut Jan 2014

Synthesis, Characterization, And Photophysical And Photochemical Properties Of 3-(4-Phenyloxy)Coumarin Containing Metallo- And Metal-Free Phthalocyanines, Nurullah Kartaloğlu, Ali̇ye Asli Esenpinar, Mustafa Bulut

Turkish Journal of Chemistry

The synthesis of novel zinc, cobalt, indium, and metal-free phthalocyanines carrying four 3-(4-phenyloxy)couma- rins in the periphery/nonperiphery were prepared by cyclotetramerization of 3-[4-(3,4-dicyanophenyloxy)phenyl]coumarin (2)/3-[4-(2,3- dicyanophenyloxy)phenyl]coumarin (3). The novel chromogenic compounds were characterized by elemental analysis, ^1H NMR, mass spectra, F-IR, and UV-vis spectral data. The effects of the coumarin units on the zinc, indium, and metal-free phthalocyanine complexes (2a/3a, 2c/3c, 2d/3d) were also investigated.

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Synthesis And Properties Of Novel Polymeric Metal-Free And Metallophthalocyanines Containing Peripherally Long 1,2-Bis[(3-Oxapropyl)Oxa]Benzene Derivatives, Ahmet Bi̇lgi̇n, Durmuş Yanmaz, Çi̇ğdem Yağci Jan 2014

Synthesis And Properties Of Novel Polymeric Metal-Free And Metallophthalocyanines Containing Peripherally Long 1,2-Bis[(3-Oxapropyl)Oxa]Benzene Derivatives, Ahmet Bi̇lgi̇n, Durmuş Yanmaz, Çi̇ğdem Yağci

Turkish Journal of Chemistry

New polymeric phthalocyanine moieties (M = 2H, Zn, Ni, Cu, and Co) were synthesized via polytetracyclomerization reaction of o-bis[3-(3,4-dicyanophenoxy)propyloxy]benzene (3), which can be obtained by the reaction of 4-nitrophthalonitrile with o-bis[(3-hydroxypropyl)oxy]benzene. Aggregation and disaggregation behavior of the polymeric phthalocyanine (5) was studied with some alkali and earth alkali metal cations. Measured intrinsic viscosities of the polymeric phthalocyanines exhibited a substantial decreasing tendency with dilution of the solution. Thermogravimetric analysis was performed under air by using DSC and DTG/TGA techniques and indicated that these polymers have good thermal stability. AC and DC electrical conductivities of the polymeric phthalocyanines were investigated in …

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Microwave-Assisted Synthesis And Characterization Of Co(Ii) Phthalocyanine And Investigation Of Its Catalytic Activity On 4-Nitrophenol Oxidation, Ece Tuğba Saka, Zekeri̇ya Biyiklioğlu, Hali̇t Kanteki̇n Jan 2014

Microwave-Assisted Synthesis And Characterization Of Co(Ii) Phthalocyanine And Investigation Of Its Catalytic Activity On 4-Nitrophenol Oxidation, Ece Tuğba Saka, Zekeri̇ya Biyiklioğlu, Hali̇t Kanteki̇n

Turkish Journal of Chemistry

In this study, new cobalt phthalocyanine containing a 2-(2-benzothiazolylthio)ethoxy group at peripheral positions has been synthesized and characterized by spectroscopic methods (IR, UV-Vis elemental analysis, and mass spectroscopies). Catalytic activity of Co(II) phthalocyanine has been investigated in the presence of oxidants such as tert-buthylhydroperoxide, m-chloroperoxybenzoic acid, and H_2O_2. Co(II) phthalocyanine shows catalytically activity and product conversion under mild conditions. To find the optimal conditions in the oxidation process, substrate ratio, oxidant ratio, temperature, and oxidant type were examined over 3 h. The results exhibit the best optimum reaction conditions in this catalytic system.

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New Soluble Amidoamine Substituted Phthalocyanines: Synthesis, Characterization, And Investigation Of Their Solution Properties, Senem Çolak, Sali̇h Zeki̇ Yildiz Jan 2014

New Soluble Amidoamine Substituted Phthalocyanines: Synthesis, Characterization, And Investigation Of Their Solution Properties, Senem Çolak, Sali̇h Zeki̇ Yildiz

Turkish Journal of Chemistry

The synthesis of tetraaminopropylamid substituted phthalocyanines was targeted to prepare enhanced soluble phthalocyanines in common solvents from hydrophobic to hydrophilic that bore nonionic groups on their periphery. Metal-free (H_2Pc) and metallophthalocyanines (Zn(II) (ZnPc), Cu(II) (CuPc) and Co(II) (CoPc)) were prepared and characterized by UV-Vis, FT-IR, and mass spectroscopies. The ^1H NMR spectra were recorded for the diamagnetic phthalocyanine species H_2Pc and ZnPc. The phthalocyanines showed sufficient solubility in common organic solvents such as dimethyl sulfoxide, tetrahydrofuran, and ethanol. However, methanol was not a good solvent for CuPc and H_2Pc. Solubility and aggregation studies of H_2Pc and ZnPc were performed in …

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Microwave-Assisted Synthesis Of Novel Nonperipherally Substituted Metallophthalocyanines Bearing (7-(Trifluoromethyl)Quinolin-4-Yl)Oxy Groups, Di̇dem Evren, Hacer Yasemi̇n Yeni̇lmez, Ayfer Kalkan Burat Jan 2014

Microwave-Assisted Synthesis Of Novel Nonperipherally Substituted Metallophthalocyanines Bearing (7-(Trifluoromethyl)Quinolin-4-Yl)Oxy Groups, Di̇dem Evren, Hacer Yasemi̇n Yeni̇lmez, Ayfer Kalkan Burat

Turkish Journal of Chemistry

The synthesis, characterization, and spectroscopic properties of novel nonperipherally tetrasubstituted metallophthalocyanines (zinc, cobalt, copper, manganese, and indium) bearing 4 (7-(trifluoromethyl)quinolin-4-yl)oxy units has been reported. The new compounds have been characterized using UV-Vis, IR, ^1H NMR, ^{13}C NMR, ^{19}F NMR, and mass spectroscopic data. The absorption properties of these new complexes were compared to those of peripherally substituted phthalocyanine derivatives. Based on the structural, spectroscopic, and absorption studies, it was found that the substitution effect altered the electronic structures significantly. The results provide useful information to understand the effect of peripheral or nonperipheral substitution on the properties of this macrocyclic ring. …

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Water-Soluble Phthalocyanines Containing Azo Dye; Microwave-Assisted Synthesis And Photochemical Properties Of Znpcs, Ci̇han Kantar, Emrah Ataci, Selami̇ Şaşmaz Jan 2014

Water-Soluble Phthalocyanines Containing Azo Dye; Microwave-Assisted Synthesis And Photochemical Properties Of Znpcs, Ci̇han Kantar, Emrah Ataci, Selami̇ Şaşmaz

Turkish Journal of Chemistry

Novel water-soluble metallophthalocyanines (M: Co, Ni, Cu, Zn) containing azo dye were characterized. The structures were confirmed by IR, UV/vis, ^1H NMR, ^{13}C NMR, mass spectroscopy, and elemental analysis. Photochemical properties and aggregation behavior of zinc phthalocyanines were investigated. Singlet oxygen quantum yields of the zinc phthalocyanines (2d, 3d, 5d, and 6d) were 0.8, 0.57, 0.71, and 0.46, respectively.

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Immobilized Metal Ion Affinity Nanospheres For \Alpha-Amylase Immobilization, Tülden Kalburcu, Müni̇re Nalan Tüzmen, Si̇nan Akgöl, Adi̇l Deni̇zli̇ Jan 2014

Immobilized Metal Ion Affinity Nanospheres For \Alpha-Amylase Immobilization, Tülden Kalburcu, Müni̇re Nalan Tüzmen, Si̇nan Akgöl, Adi̇l Deni̇zli̇

Turkish Journal of Chemistry

Immobilized metal chelate affinity chromatography (IMAC) support was practiced for \alpha-amylase immobilization. Poly(hydroxyethylmethacrylate-methacryloylamidotryptophan)-Ni^{2+} [p(HEMA-MAT)-Ni^{2+}] nanospheres, average diameter 100 nm, were produced by surfactant free emulsion polymerization. Characterizations of p(HEMA-MAT)-Ni^{2+} nanospheres were carried out by Fourier transform infrared (FTIR) spectroscopy and scanning electron microscope (SEM). In addition, average particle size, size distribution, and surface charge were specified. The amount of N-methacryloylamidotryptophan (MAT) incorporated to polymer was determined as 1.95 mmol/g polymers by using nitrogen stoichiometry. The specific surface areas of poly(hydroxyethylmethacrylate) [p(HEMA)] and p(HEMA-MAT) nanospheres were calculated as 1856 m^2/g and 1914 m^2/g, respectively. Protein adsorption increased with increasing initial protein …

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Economic Synthesis Of Quinaldinium Fluorochromate(Vi), (Qnfc), And Solvent-Free Periodic Acid Oxidation Of Alcohols Catalyzed By Qnfc, Melek Özdemi̇r, Hati̇ce Beyti̇ye Özgün Jan 2014

Economic Synthesis Of Quinaldinium Fluorochromate(Vi), (Qnfc), And Solvent-Free Periodic Acid Oxidation Of Alcohols Catalyzed By Qnfc, Melek Özdemi̇r, Hati̇ce Beyti̇ye Özgün

Turkish Journal of Chemistry

A 1:1:1 stoichiometric reaction between CrO_3, aqueous HF, and quinaldine affords orange crystalline quinaldinium fluorochromate(VI) (QnFC) (C_{10}H_9NH[CrO_3F]) in 99.4% isolated yield. A highly efficient, simple, chemoselective, and environmentally benign procedure for QnFC (3 mol%) catalyzed oxidation of primary and secondary alcohols to aldehydes and ketones using 1.1 equiv of H_5IO_6 under solvent-free conditions is described.

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Synthesis, Structure, And Luminescent Properties Of 2 Novel 5-Chlorhydroxybenzoate-Imidazole Metal-Organic Complexes, Hong Chen, Si Yuan Luo, Xiuling Wu, Yongqian Wang, Bo Hu, Chao Hu, Gang Huang, Qiao Xin Du Jan 2014

Synthesis, Structure, And Luminescent Properties Of 2 Novel 5-Chlorhydroxybenzoate-Imidazole Metal-Organic Complexes, Hong Chen, Si Yuan Luo, Xiuling Wu, Yongqian Wang, Bo Hu, Chao Hu, Gang Huang, Qiao Xin Du

Turkish Journal of Chemistry

Two novel Zn and Cu complexes with 5-chlorhydroxybenzoate and imidazole ligands, C_{41}H_{36}Zn_2N_8O_{13}Cl_4 (1) and C_{26}H_{22}Cl_2Cu_2N_8O_6 (2), were prepared by slow evaporation method. Single crystal X-ray diffraction analysis was used to determine their structures. The purity of the complexes was confirmed by powder X-ray diffraction analysis. In 1 the Zn^{2+} cation is tetracoordinated with 2 nitrogen atoms from 2 imidazoles and 2 oxygen atoms from the 2 carboxyl groups in 5-chlorhydroxybenzoate. In 2 the coordination polyhedrons of Cu^{2+} center can be described as distorted square pyramidal geometry sharing common edges, with an oxygen atom on the top of the pyramid. The …

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A Combined First Principles Tddft And Experimental Study On The Uv-Vis Spectra Properties Of M(P-Nitrophenyl Azo Resorcinol)_3 Complexes (M: Fe, Cr), Tuğba Ari̇fi̇oğlu, Meli̇s Efeçinar, Nuray Şatiroğlu Jan 2014

A Combined First Principles Tddft And Experimental Study On The Uv-Vis Spectra Properties Of M(P-Nitrophenyl Azo Resorcinol)_3 Complexes (M: Fe, Cr), Tuğba Ari̇fi̇oğlu, Meli̇s Efeçinar, Nuray Şatiroğlu

Turkish Journal of Chemistry

UV-Vis absorption data of p-nitrophenyl azo resorcinol (Magneson I) and its 2 Fe(III) and Cr(III) complexes were investigated both experimentally and theoretically. The geometries were optimized at BP86/TZVP level. The most stable spin states were computed as doublet and quartet for Fe(magneson)_3 and Cr(magneson)_3 complexes, respectively. Time-dependent density functional theory (TDDFT) was employed to explore the absorption spectra properties, whereas the solvent effects were taken into account using the polarizable continuum model (PCM). The M06, B3LYP, and PBE0 hybrid functionals together with TZVP/LANL2TZ basis sets were used for comparing the results with experimental data. The theoretical analysis of electronic structure …

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Comparison Of Chelating Ability Of No-, Ns-, Ons-, And Ono-Type Schiff Base Derivatives And Their Stability Constants Of Bis-Complexes With Copper(Ii), Hasan Atabey, Esra Findik, Hayati̇ Sari, Mustafa Ceylan Jan 2014

Comparison Of Chelating Ability Of No-, Ns-, Ons-, And Ono-Type Schiff Base Derivatives And Their Stability Constants Of Bis-Complexes With Copper(Ii), Hasan Atabey, Esra Findik, Hayati̇ Sari, Mustafa Ceylan

Turkish Journal of Chemistry

The present study includes important findings relating to the number of donor atoms, species of ligands, and stabilities of complexes. Stabilities of complexes between Cu(II) ion and NO-, NS-, ONS-, and ONO-type Schiff bases were compared. Acid-base properties of the Schiff bases were explained at 25 \pm 0.1 °C and ionic strength (I) of 0.1 M supported by NaCl. The Hyperquad computer program was used for calculation of dissociation and stability constants. The overall stability constants of their Cu(II) complexes were calculated and the various formed complexes between the Schiff bases with Cu(II) ion formulated as CuL_2, CuHL_2, CuH_2L_2, and …

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On The Peculiar Reactivity Of A C,N-Annelated Isoindole Core, Iaroslav Baglai, Valerie Maraval, Zoia Vsevolodivna Voitenko, Carine Duhayon, Yulian Mihailovich Volovenko, Remi Chauvin Jan 2014

On The Peculiar Reactivity Of A C,N-Annelated Isoindole Core, Iaroslav Baglai, Valerie Maraval, Zoia Vsevolodivna Voitenko, Carine Duhayon, Yulian Mihailovich Volovenko, Remi Chauvin

Turkish Journal of Chemistry

C-, N-, and/or O-methylation products were generated from 11H-isoindolo[2,1-a]quinazoline-5-one upon treatment with NaH followed by iodomethane under air, and possible recrystallization from methanol. Two products were fully characterized by NMR and X-ray diffraction analysis. In accordance with the HSAB principle, this soft methylating agent (MeI) leads mainly to the C,C-dimethylated product 11,11-dimethyl-11H-isoindolo[2,1-a]quinazoline-5-one, which was previously not observed, beside the N-methylated product, in a procedure using methyl tosylate as a hard methylating agent of the same substrate in the initial absence of a base. A mechanism is finally proposed for the formation of methyl 2-(3-methyl-4-oxo-3,4-dihydroquinazolin-2-yl)benzoate as an oxidation side product.

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Simulation Of Impedance Spectra Of Oxalic Acid Electroreduction To Glyoxylic Acid: Effect Of Chemical Activator, Ph, Activation Energy, And Reduction Potential, Ni̇yazi̇ Alper Tapan Jan 2014

Simulation Of Impedance Spectra Of Oxalic Acid Electroreduction To Glyoxylic Acid: Effect Of Chemical Activator, Ph, Activation Energy, And Reduction Potential, Ni̇yazi̇ Alper Tapan

Turkish Journal of Chemistry

The aim of this study was to examine qualitatively the effect of important electrochemical parameters on the faradaic impedance spectra of oxalic acid electroreduction. The impedance spectrum of a 3-step oxalic acid electroreduction mechanism was simulated by the solution of a faradaic impedance equation based on 3 state variables. Before the solution of the faradaic impedance equation, the electroreduction mechanism was analyzed and it was seen that this mechanism can be represented by an electrical circuit composed of 2 resistors and a capacitance or inductance. The effect of chemical activator on the impedance spectrum was determined by using the relation …

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Experimental Investigation Of Drag Reduction Effects Of Polymer Additives On Turbulent Pipe Flow Using Ultrasound Doppler Velocimetry, Şeri̇fe Zeybek Vural, Göknur Bayram, Yusuf Uludağ Jan 2014

Experimental Investigation Of Drag Reduction Effects Of Polymer Additives On Turbulent Pipe Flow Using Ultrasound Doppler Velocimetry, Şeri̇fe Zeybek Vural, Göknur Bayram, Yusuf Uludağ

Turkish Journal of Chemistry

Drag reduction in fully developed turbulent pipe flow with 4 concentrations (200 to 500 wppm or mg/kg) of low molecular weight sodium carboxymethylcellulose (CMC) in aqueous solutions was investigated experimentally. Drag reduction was determined by pressure drop measurements. Maximum drag reduction achieved was 22% using 500 wppm CMC solution. To observe the impact of the presence of CMC on the flow, ultrasound Doppler velocimetry (UDV) was employed to monitor the instantaneous velocity distributions. Experimental measurements were used to calculate Fanning friction factor and radial distributions of the axial time-averaged velocity, velocity fluctuation (turbulent intensity), and eddy viscosity. Two impacts of …

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Synthesis And Antimicrobial Activity Of Novel 2-[4-(1h-Benzimidazol-1-Yl)Phenyl]-1h-Benzimidazoles, Mehmet Alp, Ali̇ Hakan Göker, Nurten Altanlar Jan 2014

Synthesis And Antimicrobial Activity Of Novel 2-[4-(1h-Benzimidazol-1-Yl)Phenyl]-1h-Benzimidazoles, Mehmet Alp, Ali̇ Hakan Göker, Nurten Altanlar

Turkish Journal of Chemistry

A new class of 2-[4-(1H-benzimidazol-1-yl)phenyl]-1H-benzimidazoles (13--22) were synthesized via cyclocondensation reaction of the substituted 1,2-phenylenediamines (1, 4--12) and 1-(4-formylpheny)-1H-benzimidazole (3). The synthesized compounds were evaluated for antibacterial and antifungal activities against S. aureus, methicillin-resistant Staphylococcus aureus (MRSA), and Candida albicans by the tube dilution method. Compounds 13, 15, 18, 20, and 21 have moderate antifungal activity against C. albicans.

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Preparation Of A Novel Solid Acid Catalyst With Lewis And Brønsted Acid Sites And Its Application In Acetalization, Yijun Du, Linjun Shao, Lingyan Luo, Si Shi, Chenze Qi Jan 2014

Preparation Of A Novel Solid Acid Catalyst With Lewis And Brønsted Acid Sites And Its Application In Acetalization, Yijun Du, Linjun Shao, Lingyan Luo, Si Shi, Chenze Qi

Turkish Journal of Chemistry

A novel melamine--formaldehyde resin (MFR) supported solid acid with Lewis and Brønsted acid sites was synthesized through the immobilization of acidic ionic liquid and cuprous ion on MFR. The scanning electron microscopy (SEM) characterization showed that addition of PEG-2000 in the synthesis of MFR could promote the formation of regular particles with diameters around 3.7 \mu m. The XRD pattern demonstrated that some cuprous ions were aggregated. The catalytic performance of this acid catalyst was evaluated by acetalization. The results showed that the catalytic activity of MFR with Brønsted acid could be improved by addition of Lewis acid. The solid …

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Self-Condensation Reactions Of Acyl Phosphonates: Synthesis Of Tertiary O-Protected \Alpha-Hydroxyphosphonates, Serkan Eymur, Mehmet Göllü, Ayhan Sitki Demi̇r Jan 2014

Self-Condensation Reactions Of Acyl Phosphonates: Synthesis Of Tertiary O-Protected \Alpha-Hydroxyphosphonates, Serkan Eymur, Mehmet Göllü, Ayhan Sitki Demi̇r

Turkish Journal of Chemistry

The self-condensation reaction of benzoyl dialkyl phosphonates was developed using cyanide ion as catalyst, affording versatile tertiary O-protected \alpha-hydroxy phosphonates in moderate yield.

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