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Full-Text Articles in Physical Sciences and Mathematics

Modification Of Biomass-Derived Activated Carbon With Magnetic $\Alpha $-Fe$_{2}$O$_{3}$ Nanoparticles For Co$_{2}$ And Ch$_{4}$ Adsorption, Çi̇sem Kirbiyik Jan 2019

Modification Of Biomass-Derived Activated Carbon With Magnetic $\Alpha $-Fe$_{2}$O$_{3}$ Nanoparticles For Co$_{2}$ And Ch$_{4}$ Adsorption, Çi̇sem Kirbiyik

Turkish Journal of Chemistry

Magnetic and nonmagnetic activated carbons (ACs) were successfully prepared by using AC obtained from spent coffee grounds (SCGs) for use in CO$_{2}$ and CH$_{4}$ capture. SCGs were activated by chemical activation to produce ACs and a magnetic $\alpha $-Fe$_{2}$O$_{3}$/AC composite was prepared by coprecipitation method from the ACs produced. Magnetic and nonmagnetic samples were characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), and energy dispersive X-ray spectrometry (EDX) techniques. The textural properties of samples were determined by nitrogen adsorption-desorption using the Brunauer--Emmett--Teller (BET) and Barrett--Joyner--Halenda (BJH) methods. The results showed that the porosity of …


The Solvatochromism And Electronic Structure Of (E)-2-(2-Hydroxystyryl)Quinolin-8-Ol, Ayşegül Gümüş, Yadi̇gar Gülseven Sidir, İsa Sidir, Selçuk Gümüş Jan 2019

The Solvatochromism And Electronic Structure Of (E)-2-(2-Hydroxystyryl)Quinolin-8-Ol, Ayşegül Gümüş, Yadi̇gar Gülseven Sidir, İsa Sidir, Selçuk Gümüş

Turkish Journal of Chemistry

The (E)-2-(2-hydroxystyryl)quinolin-8-ol (abbreviated as HSQ) molecule was synthesized and characterized. The ESIPT, solvatochromism properties, electronic structure, and ground and excited electric dipole moments of this molecule were measured using absorption and fluorescence spectra recorded in 13 different solvents. Its electronic structure via electronic transitions was investigated to find the quantitative values of solvatochromism properties by LSER calculations. The ESIPT mechanism was clarified; ground and excited dipole moments were determined using solvatochromic shift methods. The DFT (B3LYP)/6-311$++$G(d,p) method and basis set with potential energy surface (PES) calculations of proton transfer were used to explain the ESIPT mechanism. NBO analysis, NLO properties, …


Why Protein Conformers In Molecular Dynamics Simulations Differ From Their Crystal Structures: A Thermodynamic Insight, Fi̇li̇ppo Pullara, Mao Wenzhi, Mert Gür Jan 2019

Why Protein Conformers In Molecular Dynamics Simulations Differ From Their Crystal Structures: A Thermodynamic Insight, Fi̇li̇ppo Pullara, Mao Wenzhi, Mert Gür

Turkish Journal of Chemistry

Conformers generally deviate structurally from their starting X-ray crystal structures early in molecular dynamics (MD) simulations. Studies have recognized such structural differences and attempted to provide an explanation for and justify the necessity of MD equilibrations. However, a detailed explanation based on fundamental physics and validation on a large ensemble of protein structures is still missing. Here we provide the first thermodynamic insights into the radically different thermodynamic conditions of crystallization solutions and conventional MD simulations. Crystallization solution conditions can lead to nonphysiologically high ion concentrations, low temperatures, and crystal packing with strong specific protein--protein interactions, not present under physiological …


Enhanced Uptake Capacities And Isosteric Heats Of Co$_{2}$ And Ch$_{4}$ Adsorption On Spent Coffee Ground Activated Carbons Loaded With Metal Ions, Çi̇sem Kirbiyik, Burak Zafer Büyükbekar, Mahmut Kuş, Mustafa Ersöz Jan 2019

Enhanced Uptake Capacities And Isosteric Heats Of Co$_{2}$ And Ch$_{4}$ Adsorption On Spent Coffee Ground Activated Carbons Loaded With Metal Ions, Çi̇sem Kirbiyik, Burak Zafer Büyükbekar, Mahmut Kuş, Mustafa Ersöz

Turkish Journal of Chemistry

Low-cost activated carbon (AC) samples obtained from waste coffee grounds were used for CO$_{2}$ and CH$_{4}$ adsorption. ACs were prepared by chemical activation and carbonized at three different temperatures. AC carbonized at 800 $^{\circ}$C showed a relatively high surface area (582.92 m$^{2}$ g$^{-1})$ and high adsorption capacities of 2.6 mmol g$^{-1}$ and 1.1 mmol g$^{-1}$ at 25 $^{\circ}$C for CO$_{2}$ and CH$_{4}$, respectively. Adsorbent samples were prepared by loading of Fe$^{3+}$ metal ions onto ACs and their adsorption capacities were compared with those of nonloaded ACs. As expected, the loading of Fe$^{3+}$ metal ions increased the adsorption capacities at all …


Synthesis, Characterization, And Kinetic Studies Of Multifunctionalized Mesoporous Silica For Adsorption Of Zinc, Ali̇me Çitak Jan 2019

Synthesis, Characterization, And Kinetic Studies Of Multifunctionalized Mesoporous Silica For Adsorption Of Zinc, Ali̇me Çitak

Turkish Journal of Chemistry

The aim of this study is to evaluate the utilization of bifunctional mesoporous silica with a platinum and propylsulfonic acid group (Pt/SBA15-PrSO$_{3}$H) as an adsorbent for the removal of Zn(II) ions from aqueous solutions. The SBA15-functionalized organosulfonic acid material was synthesized with a one-step cocondensation synthesis route. The second step was Pt loading during reduction and deposition into the aqueous suspension of the bifunctional mesoporous silica synthesized by an aqueous solution of formaldehyde as the reducing agent. The propylsulfonic acid and platinum functionalized mesoporous silica were characterized by BET, thermogravimetric analysis, and X-ray diffraction methods. The adsorption properties and thermodynamic …


Investigation Of Sulfuric Acid-Treated Activated Carbon Properties, Neda Asasian Kolur, Seyedmehdi Sharifian, Tahereh Kaghazchi Jan 2019

Investigation Of Sulfuric Acid-Treated Activated Carbon Properties, Neda Asasian Kolur, Seyedmehdi Sharifian, Tahereh Kaghazchi

Turkish Journal of Chemistry

A granulated type of commercial activated carbon (GAC) with surface area of 828 m$^{2}$/g was treated with a strong solution of sulfuric acid (98% wt.) at a temperature of 30 $^{\circ}$C . The physicochemical and porous properties and the surface chemistry of the sorbents were investigated and compared in detail. It was established that the lower temperatures of impregnation and the higher concentration of H$_{2}$SO$_{4}$ solution resulted in the introduction of higher percentages of sulfur-containing groups and smaller porosity loss. The results of EDS, FTIR, and XPS tests confirmed the introduction of sulfone groups and acidic oxygenated ones, which increased …


Synthesis, Crystal Structure, And Characterization Of Two Heterometallic Transition Metal Citrate Complexes [M $=$ Co(Ii) And Cd(Ii)], Zeki̇ Kartal, Onur Şahi̇n, Abdülkeri̇m Yavuz Jan 2019

Synthesis, Crystal Structure, And Characterization Of Two Heterometallic Transition Metal Citrate Complexes [M $=$ Co(Ii) And Cd(Ii)], Zeki̇ Kartal, Onur Şahi̇n, Abdülkeri̇m Yavuz

Turkish Journal of Chemistry

In this study, two heterometallic transition metal complexes with the formulas [CoK$_{4}(\mu _{10}$-C$_{6}$H$_{5}$O$_{7})_{2}$]$_{n}$ and [CdK($\mu _{8}$-C$_{6}$H$_{5}$O$_{7})(\mu $-H$_{2}$O)(H$_{2}$O)]$_{n}$ were synthesized as crystalline compounds. The structures of\textbf{ }these crystalline metal complexes were characterized by their spectral analyses (FT-IR, FT-Raman, thermal analysis, magnetic properties, and single-crystal X-ray diffraction techniques). According to the spectral data of the new metal complexes obtained, both metal complexes are in the monoclinic crystal system and in the P2$_{1}$/c and P2$_{1}$ space groups, respectively. The asymmetric unit of the metal complex [CoK$_{4}(\mu _{10}$-C$_{6}$H$_{5}$O$_{7})_{2}$]$_{n}$ contains one Co(II) ion, two potassium cations, and one (C$_{6}$H$_{5}$O$_{7})$ citrate ligand, whereas that of the …


Design, Synthesis, And Evaluation Of The Antimycobacterial Activity Of 3-Mercapto-1,2,4-Triazole--Pyrrole Hybrids, Gheorghe Roman, Andra-Cristina Bostanaru, Valentin Nastasa, Mihai Mares Jan 2019

Design, Synthesis, And Evaluation Of The Antimycobacterial Activity Of 3-Mercapto-1,2,4-Triazole--Pyrrole Hybrids, Gheorghe Roman, Andra-Cristina Bostanaru, Valentin Nastasa, Mihai Mares

Turkish Journal of Chemistry

A series of 3-mercapto-1,2,4-triazole--pyrrole hybrids was designed as antimycobacterial agents by employing 5-(4-(1$H$-pyrrol-1-yl)phenyl)-4$H$-1,2,4-triazole-3-thiol as the scaffold onto which several types of moieties were introduced in the triazole ring at N-4 and N-2 and as substituents of the mercapto function. The aforementioned moieties are an allyl or a phenyl moiety at N-4; an aminomethyl group at N-2; or methyl, substituted benzyl, ethoxycarbonylmethyl, or substituted phenacyl at sulfur. Investigation of the compounds in the resulting library as growth inhibitors of Mycobacterium smegmatis showed that their minimum inhibitory concentration was higher than 64 mg/L.


A Case Study Of Antiaromaticity: Carbomethoxy Cyclopropenyl Anion, Zi̇kri̇ Altun, Erdi̇ Ata Bleda, Carl Trindle Jan 2019

A Case Study Of Antiaromaticity: Carbomethoxy Cyclopropenyl Anion, Zi̇kri̇ Altun, Erdi̇ Ata Bleda, Carl Trindle

Turkish Journal of Chemistry

The simplest ideas of antiaromaticity refer to regular monocyclic systems and the eigenfunctions of the H\"{u}ckel Hamiltonian for 4n $\pi $ electrons in such systems. The antiaromaticity is expressed in the energy penalty for such idealized systems relative to the H\"{u}ckel energy for 2n noninteracting $\pi $ pairs. Observed systems seldom achieve the regular planar geometry assumed in this picture, owing to their ability to ease the antiaromaticity penalty by departures from the regular geometry and also by export of the 4n $\pi $ electrons' charge to substituents. In this report we estimate numerical values for the stabilization derived from …


Preparation Of Epoxidized Sunflower Oil Metal Soap Derivatives And Their Use As Heat Stabilizers For Polyvinyl Chloride, Ouassila Chelil, Naima Belhaneche-Bensemra, Daniel Lopez Garcia, Marta Fernandez-Garcia, Mohamed Tahar Benaniba Jan 2019

Preparation Of Epoxidized Sunflower Oil Metal Soap Derivatives And Their Use As Heat Stabilizers For Polyvinyl Chloride, Ouassila Chelil, Naima Belhaneche-Bensemra, Daniel Lopez Garcia, Marta Fernandez-Garcia, Mohamed Tahar Benaniba

Turkish Journal of Chemistry

The aim of this work was to prepare metal soaps of epoxidized sunflower oil (ESO) and use them as thermal stabilizers for polyvinyl chloride (PVC). For that purpose, commercial sunflower oil was first epoxidized and then used to prepare (Ba, Zn, Pb, and Cd) metal soap derivatives, which were characterized by Fourier transform infrared (FTIR) spectroscopy, thermogravimetric analysis (TGA), and differential scanning calorimetry (DSC). The prepared metal soaps derivatives of ESO were used as thermal stabilizers for plasticized PVC. Discoloration, residual thermal stability at 200 $^{\circ}$C , and rheological properties of PVC samples were tested. The structural modifications were investigated …


Intermolecular Complexes Of Halocyclopropenone Derivatives With The Hypohalous Acids Hof, Hocl, Hobr, And Hoi, Dariush Mirzaei, Abedien Zabardasti, Yaghoub Mansourpanah Jan 2019

Intermolecular Complexes Of Halocyclopropenone Derivatives With The Hypohalous Acids Hof, Hocl, Hobr, And Hoi, Dariush Mirzaei, Abedien Zabardasti, Yaghoub Mansourpanah

Turkish Journal of Chemistry

The intermolecular interactions between halocyclopropenone derivatives (HC$_{3}$OX; X $=$ I, Br, Cl, and F) and hypohalous acids (HOY; Y $=$ I, Br, Cl, and F) were studied via the MP2 method utilizing the aug-cc-pVTZ and aug-cc-pVTZ(-PP) basis sets. The three types of complexes were hydrogen bonds, halogen bonds, and complexes containing both hydrogen and halogen bonds. The results obtained indicated that interactions in the Type 1 complexes were stronger than those in Types 2 and 3. The H-O bonds revealed red shifts with complex formation in Types 1 and 2. The O-Y bonds displayed red shifts in the Type 3 …


Synthesis And Antitumor Activities Of 2-(Piperidin-4-Yl)-Thiazole-4-Carboxamides Analogues Of Tubulysins, Xiangfu Peng, Mingsha Shao, Shuchao Ma, Lei Yao Jan 2019

Synthesis And Antitumor Activities Of 2-(Piperidin-4-Yl)-Thiazole-4-Carboxamides Analogues Of Tubulysins, Xiangfu Peng, Mingsha Shao, Shuchao Ma, Lei Yao

Turkish Journal of Chemistry

}Tubulysins are a family of natural products that exhibit potent antitumor activities, which have attracted much attention from synthetic and medicinal chemists. Previous attempts to aromatize the Tuv part of tubulysin analogues led to a loss in antitumor activity, which suggested that the Ile and Tuv fragments of these analogues were adopting different conformations than the natural products. In this study, a series of 2-(piperidin-4-yl)-thiazole-4-carboxamides have been prepared to investigate whether an intramolecular H-bond between key NH and OH groups is responsible for the conformational control. The antitumor activities of these analogues have been screened using MDA-MB-231-breast, Siha-cervical, MCF7-breast, and …


Effect Of Crosslinking Patterns On The Properties Of Conjugated Microporous Polymers, Hakan Bi̇ldi̇ri̇r Jan 2019

Effect Of Crosslinking Patterns On The Properties Of Conjugated Microporous Polymers, Hakan Bi̇ldi̇ri̇r

Turkish Journal of Chemistry

Syntheses and detailed spectroscopic characterizations of two similar conjugated microporous polymers formed by A4 $+$ B2 and A2 $+$ B3 type functional monomers via Sonogashira--Hagihara polycondensation are presented in this report. The two porous polymeric networks possess mono-, di-, and tri- (1-, 1,4-, and 1,3,5-, respectively) substituted benzene rings and fused thiophenic moieties (dithienothiophenes). Because of the different conjugation patterns, their solid state nuclear magnetic resonance, infrared, and ultraviolet/visible light absorption analyses indicated significant differences. Besides the discussions on the porous properties of the obtained polymeric networks, the presented spectroscopic investigations can be useful for identifying the structure-property relationship of …


A Microwave-Assisted Highly Stereoselective One-Pot Wittig Reaction Under Solvent-Free Conditions, Kalyani Rajkumari, Bittu Lama, Lalthazuala Rokhum Jan 2019

A Microwave-Assisted Highly Stereoselective One-Pot Wittig Reaction Under Solvent-Free Conditions, Kalyani Rajkumari, Bittu Lama, Lalthazuala Rokhum

Turkish Journal of Chemistry

We report a novel microwave-assisted two-step, one-pot protocol for the synthesis of olefins (alkenes) via Wittig reaction. The reaction was carried out under solvent-free conditions using basic alumina both as a heterogeneous catalyst and a solid support. Varieties of aromatic aldehydes were converted into their corresponding olefins within 30-50 min with good to excellent yields. An excellent predominance of E-isomers over Z-isomers (up to 100% E-selectivity) for all the olefin products was observed. This showed the attractive stereocontrol of our reported protocol. In addition, owing to the solid-state nature of the reactions, our procedure prevented the need for tedious aqueous …


Effect Of Brij 35 And Saponin Surfactants On Adsorption Of Diethylstilbestrol As An Emerging Estrogenic Contaminant By Clinoptilolite In Batch And Fixed-Bed Column Experiments, Reyhaneh Saadi, Reza Fazaeli, Leila Vafajoo, Iraj Naser Jan 2019

Effect Of Brij 35 And Saponin Surfactants On Adsorption Of Diethylstilbestrol As An Emerging Estrogenic Contaminant By Clinoptilolite In Batch And Fixed-Bed Column Experiments, Reyhaneh Saadi, Reza Fazaeli, Leila Vafajoo, Iraj Naser

Turkish Journal of Chemistry

In this study, natural clinoptilolite was modified by saponin and Brij 35 surfactants to remove diethylstilbestrol (DES) from wastewater in batch and continuous systems. The optimum pH, amount of adsorbent, contact time, and temperature were 11, 10 g/L, 12 h, and 35 $^{\circ}$C, respectively, for the process. The equilibrium data agreed well with the Langmuir isotherm for natural clinoptilolite (NC), natural clinoptilolite modified by Brij 35 (NC-Brij), and natural clinoptilolite modified by saponin surfactants (NC-saponin) compared to other isotherms. The maximum adsorption capacities resulting from the Langmuir isotherm for NC, NC-Brij, and NC-saponin were 8.012, 23.64, and 39.525 mg/g, respectively. …


Electrochemical Oxidation Of Curcuminoids: An Experimental And Computational Investigation, Zeynep Kalaycioğlu, Nurgül Karadaş, Mehmet Emi̇n Çinar, Si̇bel Ayşil Özkan, Duri̇şehvar Özer Ünal, Ayşegül Gölcü, Fatma Bedi̇a Eri̇m Jan 2019

Electrochemical Oxidation Of Curcuminoids: An Experimental And Computational Investigation, Zeynep Kalaycioğlu, Nurgül Karadaş, Mehmet Emi̇n Çinar, Si̇bel Ayşil Özkan, Duri̇şehvar Özer Ünal, Ayşegül Gölcü, Fatma Bedi̇a Eri̇m

Turkish Journal of Chemistry

Curcuminoids, reported to have important biological properties, such as antioxidant, anti-Alzheimer, and antidiabetic properties, comprise curcumin (CRM; 1,7-bis [4-hydroxy-3-methoxyphenyl]-1,6-heptadiene-3,5-dione) and its derivatives demethoxycurcumin (DMC; (E,6E)-1-(3,4-dimethoxy-cyclohexyl)-7-(3,4-dimethoxyphenyl)hepta-1,6-diene-3,5-dione) and bisdemethoxycurcumin (BDMC; 1,7-bis[4-hydroxyphenyl]-1,6-heptadiene-3,5-dione). Their electrochemical oxidations are thoroughly explored by applying cyclic and differential pulse voltammetric techniques. The dependence of current intensities and potentials on pH, concentration, scan rate, and nature of the buffer was investigated. The outcome is supported by density functional theory computations indicating the transfer of 4-e$^{-}$/H$^{+}$, 6-e$^{-}$/H$^{+}$, and 8-e$^{-}$/H$^{+}$ couples involved in the oxidation mechanisms of CRM, DMC, and BDMC, respectively, leading to the formation of the same oxidized product.


Determination Of N-Acetylcysteine In The Presence Of Ciprofloxacin Or Levofloxacin In Microparticulate Dry Powder Inhalers, Yağmur Akdağ Çayli, Selma Şahi̇n, Emi̇rhan Nemutlu, Levent Öner Jan 2019

Determination Of N-Acetylcysteine In The Presence Of Ciprofloxacin Or Levofloxacin In Microparticulate Dry Powder Inhalers, Yağmur Akdağ Çayli, Selma Şahi̇n, Emi̇rhan Nemutlu, Levent Öner

Turkish Journal of Chemistry

A fast and easy method was validated for simultaneous determination of ciprofloxacin hydrochloride monohydrate (CP), levofloxacin hemihydrate (LV), and N-acetylcysteine (NAC) in samples. The analysis was performed on a C$_{18}$ column (250 x 4.6 mm, 5 μm) (Inertsil ODS-3V) using an isocratic elution method with a mobile phase composed of 25 mM KH$_{2}$PO$_{4}$ (pH 3.0) and methanol (72:28, v/v) at a flow rate of 1 mL/min. UV detection was performed at 214 nm for NAC and 293 nm for CP and LV. The method was validated for linearity, accuracy, precision (repeatability and reproducibility), specificity, sensitivity, and stability. The calibration study …


Qualitative And Quantitative Determination Of The Effective Components Of The Plants In Different Herbal Slimming Products In Turkey By Hplc, Benan Dursunoğlu, Hafi̇ze Yuca, Sefa Gözcü, Bi̇lal Yilmaz, Zühal Güvenalp Jan 2019

Qualitative And Quantitative Determination Of The Effective Components Of The Plants In Different Herbal Slimming Products In Turkey By Hplc, Benan Dursunoğlu, Hafi̇ze Yuca, Sefa Gözcü, Bi̇lal Yilmaz, Zühal Güvenalp

Turkish Journal of Chemistry

Obesity is a serious disease that can be due to genetic and environmental reasons and is defined by the World Health Organization as abnormal or excessive fat accumulation that may impair health. There is an increasing trend towards herbal slimming products in obesity treatment. The quality control analysis of these products is important for public health. In this study, new, simple, and sensitive high performance liquid chromatography methods were developed for qualitative and quantitative determination of arbutin, hydroquinone, ursolic acid, chlorogenic acid, epigallocatechin gallate, epigallocatechin, epicatechin gallate, and catechin in eleven herbal slimming products in Turkey containing Camellia sinensis, Ilex …


Comparative Study On Physicochemical And Mechanical Characterization Of New Nanocarbon-Based Hydroxyapatite Nanocomposites, Reka Barabas, Dennis Deemter, Gabriel Katona, Gabriel Batin, Laszlo Barabas, Liliana Bizo, Oana Cadar Jan 2019

Comparative Study On Physicochemical And Mechanical Characterization Of New Nanocarbon-Based Hydroxyapatite Nanocomposites, Reka Barabas, Dennis Deemter, Gabriel Katona, Gabriel Batin, Laszlo Barabas, Liliana Bizo, Oana Cadar

Turkish Journal of Chemistry

This study evaluated the effect of different additives such as nanocarbon compounds (0.5, 1.0, and 2.0 wt.%) with different morphologies and gelatin (Gel) (10 wt.%) on the mechanical properties of hydroxyapatite (Hap)-based nanocomposites (NCs). The NCs were prepared using the innovation process "SmartBox" based on the Internet of things (IoT), which provides process control and reproducibility, and they were characterized by X-ray diffraction, particle size distribution, transmission electron microscopy, Fourier transform infrared spectroscopy, and thermal analysis. The compressive strength tests demonstrated that the use of grapheme oxide (Hap_ GO_ 2.0 - 133 N/mm$^{2})$, and/or Gel (Hap_ Gel - 152 N/mm$^{2})$ …


Improving The Mechanical And Thermal Properties Of Chlorinated Poly(Vinyl Chloride) By Incorporating Modified Caco$_{3}$ Nanoparticles As A Filler Jan 2019

Improving The Mechanical And Thermal Properties Of Chlorinated Poly(Vinyl Chloride) By Incorporating Modified Caco$_{3}$ Nanoparticles As A Filler

Turkish Journal of Chemistry

Chlorinated poly(vinyl chloride) (CPVC)/calcium carbonate nanocomposites were successfully prepared by the incorporation of calcium carbonate (CaCO$_{3})$ nanoparticles into the CPVC matrix. The compatibility between the two phases was obtained by surface modification of the CaCO$_{3}$ nanoparticles with stearic acid, leading to improved material performance. The effects of the addition of different amounts of CaCO$_{3}$ nanoparticles to the CPVC on the thermal, mechanical, and morphological characteristics of the CPVC/CaCO$_{3}$ nanocomposites were investigated. The thermal stability of the CPVC/CaCO$_{3}$ nanocomposites was evaluated by thermogravimetric analysis~and differential scanning calorimetry. In addition, the surface texture of the CPVC and the dispersion of the CaCO$_{3}$ …


Effect Of Fe Substitution On The Partial Oxidation Of Methane To Syngas Over La$_{0.7}$Sr$_{0.3}$Co$_{1-Y}$Fe$_{Y}$O$_{3-\Delta}$ Perovskites, Adilah Aliyatulmuna, Perry Burhan, Bambang Prijamboedi, Hamzah Fansuri, Irmina Kris Murwani Jan 2019

Effect Of Fe Substitution On The Partial Oxidation Of Methane To Syngas Over La$_{0.7}$Sr$_{0.3}$Co$_{1-Y}$Fe$_{Y}$O$_{3-\Delta}$ Perovskites, Adilah Aliyatulmuna, Perry Burhan, Bambang Prijamboedi, Hamzah Fansuri, Irmina Kris Murwani

Turkish Journal of Chemistry

In this research, a series of La$_{0.7}$Sr$_{0.3}$Co$_{1-y}$Fe$_{y}$O$_{3-\delta }$ ($y =$ 0.0--0.4) was successfully synthesized by a solid-state reaction method and syngas production studies were performed using gas chromatography. Thermogravimetric analysis characterized the concentration of Fe$^{3+}$, which gave a low H$_{2}$/CO ratio over La$_{0.7}$Sr$_{0.3}$Co$_{1-y}$Fe$_{y}$O$_{3-\delta }$ without the presence of molecular oxygen. All samples possessed a purely rhombohedral structure. The incorporation of more Fe increased the lattice parameter and changed XRD peaks of the La$_{1-x}$Sr$_{x}$Co$_{0.8}$Fe$_{0.2}$O$_{3}$ from sharp and single to double. Among the catalyst powders tested for syngas production activity, La$_{0.7}$Sr$_{0.3}$Co$_{0.6}$Fe$_{0.4}$O$_{3-\delta }$ ($y =$ 0.4) had the low molar ratio of H$_{2}$/CO …


Sustainable Process For The Production Of Symmetrical Dibasic Acid Ester-Based Thermal Energy Storage Materials From Lipids, Ayhan Yildirim, Kaan Kiraylar Jan 2019

Sustainable Process For The Production Of Symmetrical Dibasic Acid Ester-Based Thermal Energy Storage Materials From Lipids, Ayhan Yildirim, Kaan Kiraylar

Turkish Journal of Chemistry

Oleochemical-based long-chain diesters are potential organic phase change materials convenient for thermal energy storage. The development of efficient and green methods is an important requirement for the preparation of these environmentally friendly compounds, which also are finding wide industrial application. Thus, in the present work, a series of dibasic acid esters were synthesized through ionic liquid catalyzed scalable chemical esterification or transesterification reactions in a solvent-free medium. The starting compounds, dicarboxylic acids or their methyl esters and fatty alcohols or cholesterol, were reacted in the ratio of 1:2 respectively and the synthesized esters were characterized by FT-IR, $^{1}$H NMR, and …


Spectrophotometric Methods For The Determination Of Fluoride Ion Using Indole-3-Acetic Acid Interaction With Iron(Iii), Emi̇ne İlknur Öztürk, Adnan Kenar, Mehmet Levent Aksu, Mustafa Taşteki̇n Jan 2019

Spectrophotometric Methods For The Determination Of Fluoride Ion Using Indole-3-Acetic Acid Interaction With Iron(Iii), Emi̇ne İlknur Öztürk, Adnan Kenar, Mehmet Levent Aksu, Mustafa Taşteki̇n

Turkish Journal of Chemistry

This study is related to the determination of fluoride ion by the conversion of pink-colored Fe(III) and indole-3-acetic acid (IAA) into a colorless hexafluoride ferrite complex with the addition of fluoride. The optimum conditions of the complex formation were found to be pH 1.7 and a temperature of 60 $^{\circ}$C C. The maximum absorption wavelength of the complex and the detection limit of the method were 525 nm and 0.26 mg/L, respectively. The interfering effects of the different cations (Ag$^{+}$, Al$^{3+}$, Ba$^{2+}$, Ca$^{2+}$, Cd$^{2+}$, Co$^{2+}$, Cu$^{2+}$, K$^{+}$, Mg$^{2+}$, Na$^{+}$, Ni$^{2+}$, Pb$^{2+})$ and anions (SO$_{4}^{2-}$, SO$_{3}^{2-}$, NO$_{2}^{-}$, I$^{-}$, Br$^{-}$, Cl$^{-}$, SCN$^{-}$, …


Synthesis And Characterization Of Polycaprolactone-Based Segmented Polyurethanes, Aysun Güney, Aysel Kiziltay, Nesri̇n Hasirci, Tuğba Endoğan Tanir Jan 2019

Synthesis And Characterization Of Polycaprolactone-Based Segmented Polyurethanes, Aysun Güney, Aysel Kiziltay, Nesri̇n Hasirci, Tuğba Endoğan Tanir

Turkish Journal of Chemistry

Segmented polyurethanes were synthesized by the reactions of poly($\varepsilon $-caprolactone) (PCL)-diol and 1,6-hexamethylene diisocyanate through bulk polymerization without using solvent, initiator, or catalyst. Phase separation and hydrogen bond formation between hard segments or between hard and soft segments were examined by Fourier transform infrared spectroscopy (FTIR)-ATR and X-ray diffraction (XRD), while physical and mechanical properties were studied by atomic force microscope, differential scanning calorimeter, dynamic mechanical analysis, and tensile tester. When the diisocyanate content was increased, deconvolution results of FTIR-ATR in C$=$O and N-H regions demonstrated better miscibility of the segments and XRD results showed a significant decrease in the …


Removal Of Cr(Vi) From Wastewater Through Glycine Assisted Synthesis Of Tio$_{2}$, Bi̇lsen Kurtteki̇n, Demet Özer, Nurşen Altuntaş Öztaş Jan 2019

Removal Of Cr(Vi) From Wastewater Through Glycine Assisted Synthesis Of Tio$_{2}$, Bi̇lsen Kurtteki̇n, Demet Özer, Nurşen Altuntaş Öztaş

Turkish Journal of Chemistry

In this study, titanium dioxide was synthesized via solution combustion method. Titanium(IV) oxysulfate was used as a titanium source. The fuel type, reaction time, and reaction temperature were tested for optimization. The glycine was set as a suitable fuel. Structural properties of the final product were characterized by p-XRD. Scanning electron microscopy (SEM) and BET techniques were used to examine the morphology. The synthesized products were compared to the commercial TiO$_{2}$ and it was found that the titanium dioxide with the high surface area (63.628 m$^{2}$/g) has been successfully synthesized by solution combustion method with time and energy saving. In …


Boric Acid As An Efficient And Green Catalyst For The Synthesis Of 2-Amino-4,6-Diarylnicotinonitrile Under Microwave Irradiation In Solvent-Free Conditions, Zahra Hosseinzadeh, Ali Ramazani, Nima Razzaghi-Asl, Katarzyna Slepokura, Tadeusz Lis Jan 2019

Boric Acid As An Efficient And Green Catalyst For The Synthesis Of 2-Amino-4,6-Diarylnicotinonitrile Under Microwave Irradiation In Solvent-Free Conditions, Zahra Hosseinzadeh, Ali Ramazani, Nima Razzaghi-Asl, Katarzyna Slepokura, Tadeusz Lis

Turkish Journal of Chemistry

Microwave irradiation has been used to improve the one-pot synthesis of substituted 2-amino-4,6-diarylnicoti- nonitrile in the presence of boric acid as an efficient and green catalyst under solvent-free conditions within 48--60 s. All the analogs that have not been reported previously were characterized by their melting points, IR, $^{1}$H NMR, and $^{13}$C NMR spectra. One of the structures was verified by the analysis of a single crystal. The reported synthetic procedure provided remarkable advantages such as short reaction times, excellent yield, facile workup, and the use of a green catalyst.


Synthesis Of Tetrakis Bromine Terminated Phthalocyanine And Its Methyl Methacrylate Polymers Via Atr, Tuba Çakir Çanak, Damla Yeşi̇ldağ, Ilgin Nar, Esi̇n Hamuryudan, İbrahi̇m Ersi̇n Serhatli Jan 2019

Synthesis Of Tetrakis Bromine Terminated Phthalocyanine And Its Methyl Methacrylate Polymers Via Atr, Tuba Çakir Çanak, Damla Yeşi̇ldağ, Ilgin Nar, Esi̇n Hamuryudan, İbrahi̇m Ersi̇n Serhatli

Turkish Journal of Chemistry

A phthalocyanine (Pc) initiator, tetrakis(2-bromopropyloxyester)ethylthiophthalocyaninatozinc(II) (ZnPc-Br), was prepared and successfully applied to atom transfer radical polymerization (ATRP) of methyl methacrylate (MMA) for the first time. Bromine end groups of the synthesized Pc took part in the initiation of the MMA chain growth. Polymerization was demonstrated by monomodal molecular weight distribution of the synthesized polymers and their increasing molecular weight behavior with reaction time. UV-Vis absorption, fluorescence, and transmittance properties of the polymers were also examined. The results indicate that the ZnPc-Br-based initiator is potentially applicable in ATRP applied to MMA in order to obtain and develop functional acrylic materials.


Parameterization, Kinetics, And Adsorption Isotherm Of Electrocoagulation Process Of Bromothymol Blue In Aqueous Medium Using Aluminum Electrodes, Okon Abakedi, Victor Mkpenie, John Okafor Jan 2019

Parameterization, Kinetics, And Adsorption Isotherm Of Electrocoagulation Process Of Bromothymol Blue In Aqueous Medium Using Aluminum Electrodes, Okon Abakedi, Victor Mkpenie, John Okafor

Turkish Journal of Chemistry

The removal of bromothymol blue (BTB) from aqueous solution was studied by electrocoagulation (EC) technique using aluminum electrodes. The various experimental conditions known to influence the EC process were parameterized, including the effects of temperature, concentration, current density, pH, and treatment time. The results obtained have shown that optimum removal efficiency of 99.9% was realized at a current density of 20 mA/cm$^{2}$ and pH of 4.7. The adsorption process showed a pseudo-first-order kinetic model as the best fit to the EC data. Freundlich and Langmuir adsorption isotherms supported the adsorption of BTB on aluminum hydroxide being the in situ generated …


Alpha-Pyrone Glycosides From Scutellaria Salviifolia Benth, Zeynep Doğan, Kan'ichiro Ishiuchi, Toshiaki Makino, İclal Saraçoğlu Jan 2019

Alpha-Pyrone Glycosides From Scutellaria Salviifolia Benth, Zeynep Doğan, Kan'ichiro Ishiuchi, Toshiaki Makino, İclal Saraçoğlu

Turkish Journal of Chemistry

Scutellaria salviifolia Benth. is an endemic species growing in Turkey that belongs to the family Lamiaceae. As a result of a phytochemical study on the aerial parts of S. salviifolia Benth., two new and 10 known compounds were isolated from the aqueous fraction of methanolic extract. The new compounds are methyl-$\alpha $-pyrone glucosides, 3,4-dihydroxy-6-methylpyran-2-one 3-$O$-$\beta $-glucopyranoside (=scusalvioside A, 1), and 3,4-dihydroxy-6-methylpyran-2-one 3-$O$-$\beta $-(6$'$-$O$-$E$-caffeoyl) glucopyranoside (=scusalvioside B, 2) with new skeletal structures. Along with them, 3 phloroglucinol glucosides [phlorin (3), tadehaginoside (4), and 6$^{\prime \prime} $-$O$-$Z$-$p$-coumaroyl phloroglucinol-1-$O$-$\beta $-glucopyranoside (5)], 6 flavonoids [apigenin (6), apigenin 5-$O$-$\beta $-glucopyranoside (7), isoschaftoside (8), luteolin 7-$O$-$\beta …


A Theoretical Investigation On The Activation Of Small Molecules By A Disilenide: A Dft Prediction, Cem Burak Yildiz, Akin Azi̇zoğlu Jan 2019

A Theoretical Investigation On The Activation Of Small Molecules By A Disilenide: A Dft Prediction, Cem Burak Yildiz, Akin Azi̇zoğlu

Turkish Journal of Chemistry

Herein, we proposed several mechanistic scenarios for activation of small molecules (NH$_{3}$, CO$_{2}$, CS$_{2}$, H$_{2}$, CH$_{4}$, N$_{2}$, and N$_{2}$O) by a disilicon analogue of a vinyl anion (1H) using density functional theory (DFT) calculations. The DFT results established that all the possible reactions to yield a variety of potential products have an exergonic nature except for the activation of N$_{2}$ with the obtained overall energy of $\Delta $G = 33.6 kcal mol$^{-1}$. Moreover, the highest exergonic character was $\Delta $G = $-$95.8 kcal mol$^{-1}$ for N$_{2}$O. Therefore, the findings reveal that 1H can be considered a suitable candidate for activation …