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Articles 11131 - 11160 of 12521
Full-Text Articles in Physical Sciences and Mathematics
Highly Selective Schiff Base Derivatives For Colorimetric Detection Of Al$^{3+}$, Zi̇ya Aydin, Mustafa Keleş
Highly Selective Schiff Base Derivatives For Colorimetric Detection Of Al$^{3+}$, Zi̇ya Aydin, Mustafa Keleş
Turkish Journal of Chemistry
Schiff base derivatives NBAR and NSAR were developed for selective detection of Al$^{3+}$ in aqueous solution. UV-vis spectroscopic studies revealed that NBAR and NSAR showed marked sensitivity and selectivity to Al$^{3+}$ in acetonitrile (ACN)/water (v/v, 1:1, pH 6.80). The NBAR and NSAR receptors bound Al$^{3+}$ in a 2:1 stoichiometry with apparent binding constants 4.09 $\times $ 10$^{11}$ M$^{-2}$ and 1.65 $\times $ 10$^{12}$ M$^{-2}$, respectively. They also displayed distinct changes in color upon the alteration of free Al$^{3+}$ levels in solution with reversible responses and showed little interference with other metal ions.
Voltammetric Analysis Of Disulfiram In Pharmaceuticals With A Cyclic Renewable Silver Amalgam Film Electrode, Sylwia Smarzewska, Natalia Festinger, Monika Skowron, Dariusz Guziejewski, Radovan Metelka, Mariola Brycht, Witold Ciesielski
Voltammetric Analysis Of Disulfiram In Pharmaceuticals With A Cyclic Renewable Silver Amalgam Film Electrode, Sylwia Smarzewska, Natalia Festinger, Monika Skowron, Dariusz Guziejewski, Radovan Metelka, Mariola Brycht, Witold Ciesielski
Turkish Journal of Chemistry
Electrochemical properties of disulfiram, representative of highly significant bioactive compounds, were studied with a cyclic renewable silver amalgam film electrode (Hg(Ag)FE) using square wave cathodic stripping voltammetry (SWCSV). The influence of various factors such as pH, buffer concentration, buffer composition, and SWCSV parameters on current response was investigated. The optimum results in terms of signal shape and intensity were recorded in Britton--Robinson buffer (pH 7.5) at -0.5 V versus Ag/AgCl/3 mol L$^{-1}$ KCl. An elaborated electroanalytical procedure was used to determine disulfiram at the Hg(Ag)FE in the concentration range from 0.05 to 5.00 $\mu $M. Precision, repeatability, and accuracy of …
Synthesis And Cytotoxicity Of Novel Thioxo-Quinazolino[3,4-$A$]Quinazolinones, Negar Mohammadhosseini, Mina Saeedi, Shahram Moradi, Mohammad Mahdavi, Omidreza Firuzi, Alireza Foroumadi, Abbas Shafiee
Synthesis And Cytotoxicity Of Novel Thioxo-Quinazolino[3,4-$A$]Quinazolinones, Negar Mohammadhosseini, Mina Saeedi, Shahram Moradi, Mohammad Mahdavi, Omidreza Firuzi, Alireza Foroumadi, Abbas Shafiee
Turkish Journal of Chemistry
Various thioxo-quinazolino[3,4-$a$]quinazolinones were prepared and evaluated for their cytotoxicity in MOLT-4 (lymphoblastic leukemia) and MCF-7 (breast adenocarcinoma) cell lines. Synthesis of the target compounds was started from isatoic anhydride. Successive reaction of isatoic anhydride with benzylamine and 2-nitrobenzaldehyde, reduction of the nitro group, and reaction with CS$_{2}$ gave 12-benzyl-6-thioxo-6,7,11b,12-tetrahydro-13$H$-quinazolino[3,4-$a$]quinazolin-13-one. The latter compound reacted with various 2-chloro-$N$-substituted acetamides to afford the corresponding fused quinazolinone derivatives.
Synthesis And Characterization Of Magnetic Amidoximated Chitosan-G Poly(Polyacrylonitrile)/Laponite Rd Nanocomposites With Enhanced Adsorption Capacity For Cu$^{2+}$, Gholam Reza Mahdavinia, Ebrahim Shokri
Synthesis And Characterization Of Magnetic Amidoximated Chitosan-G Poly(Polyacrylonitrile)/Laponite Rd Nanocomposites With Enhanced Adsorption Capacity For Cu$^{2+}$, Gholam Reza Mahdavinia, Ebrahim Shokri
Turkish Journal of Chemistry
Magnetic amidoximated nanocomposites based on a combination of chitosan and magnetic laponite RD were prepared and examined for the removal of Cu$^{2+}$ from aqueous solutions. Magnetic laponite RD was prepared by an in situ method. In order to prepare magnetic amidoximated nanocomposites, acrylonitrile was grafted to chitosan in the presence of magnetic laponite RD. Then the nitrile pendants on magnetic chitosan-g-polyacrylonitrile/laponite RD (mChtioPANLap) were converted to amidoxime groups. We developed a polyamidoximated magnetic nanocomposite based on a mixture of chitosan/laponite RD, possessing a high adsorption capacity for Cu$^{2+}$. By introducing magnetic laponite RD the adsorption capacity of nanocomposites for Cu$^{2+}$ …
Isocoumarins And 3,4-Dihydroisocoumarins, Amazing Natural Products: A Review, Aisha Saddiqa, Osman Çakmak, Muhammad Usman
Isocoumarins And 3,4-Dihydroisocoumarins, Amazing Natural Products: A Review, Aisha Saddiqa, Osman Çakmak, Muhammad Usman
Turkish Journal of Chemistry
The isocoumarins are naturally occurring lactones that constitute an important class of natural products exhibiting an array of biological activities. A wide variety of these lactones have been isolated from natural sources and, due to their remarkable bioactivities and structural diversity, great attention has been focused on their synthesis. This review article focuses on their structural diversity, biological applications, and commonly used synthetic modes.
Impact Of Surface Modification Of Green Algal Biomass By Phosphorylation On The Removal Of Copper(Ii) Ions From Water, Zakaria Al-Qodah, Mohammad Al-Shannag, Abdulaziz Amro, Eman Assirey, Mustafa Bob, Khalid Bani-Melhem, Malek Alkasrawi
Impact Of Surface Modification Of Green Algal Biomass By Phosphorylation On The Removal Of Copper(Ii) Ions From Water, Zakaria Al-Qodah, Mohammad Al-Shannag, Abdulaziz Amro, Eman Assirey, Mustafa Bob, Khalid Bani-Melhem, Malek Alkasrawi
Turkish Journal of Chemistry
A series of batch lab-scale experiments were performed to investigate the performance of dead phosphorylated algal biomass of Spirogyra species for the bioadsorption of Cu$^{+2}$ ions from aqueous solutions. FT-IR and SEM analyses were performed to characterize the phosphorylated and raw algae. The SEM analysis indicated that the phosphorus content increases by about 5 times. The isotherm equilibrium data indicated that phosphorylation enhances the removal of Cu$^{+2}$ from water by about 20%. The experimental isotherms fit well to Langmuir models with $R^{2}$ values close to 0.99. Adsorption kinetic study was conducted to investigate the effect of initial Cu$^{+2}$ concentrations, pH, …
Homopolymerization And Synthesis Of A New Methacrylate Monomer Bearing A Boron Side Group: Characterization And Determination Of Monomer Reactivity Ratios With Styrene, Tuba Çakir Çanak, Serkan Akpinar, İ. Ersi̇n Serhatli
Homopolymerization And Synthesis Of A New Methacrylate Monomer Bearing A Boron Side Group: Characterization And Determination Of Monomer Reactivity Ratios With Styrene, Tuba Çakir Çanak, Serkan Akpinar, İ. Ersi̇n Serhatli
Turkish Journal of Chemistry
Boron methacrylate (BAc) monomer was synthesized via an esterification reaction. Boric acid, neopentyl glycol, and 2-hydroxyethyl methacrylate (HEMA) were reacted to obtain boron-containing acrylic monomer. Characterization was achieved by FT-IR, $^{13}$C NMR, $^{1}$H NMR, and $^{11}$B NMR and the results for the synthesized monomer were compared to those for HEMA. Homopolymer and copolymers with styrene (St) were synthesized via free radical polymerization. The properties of the synthesized styrene copolymers were investigated using several techniques. Monomer reactivity ratios for the studied monomer pair were calculated using the extended Kelen-Tüdos method. Copolymerization compositions and reactive ratios showed that the obtained copolymers had …
Hydrolysis Of Ammonia Borane And Hydrazine Borane By Poly($N$-Vinyl-2-Pyrrolidone)-Stabilized Copd Nanoparticles For Chemical Hydrogen Storage, Murat Rakap, Bayram Abay, Ni̇hat Tunç
Hydrolysis Of Ammonia Borane And Hydrazine Borane By Poly($N$-Vinyl-2-Pyrrolidone)-Stabilized Copd Nanoparticles For Chemical Hydrogen Storage, Murat Rakap, Bayram Abay, Ni̇hat Tunç
Turkish Journal of Chemistry
For the first time the synthesis of poly($N$-vinyl-2-pyrrolidone)-stabilized cobalt-palladium nanoparticles by an easy method, their characterization, and their use as active catalysts for hydrogen release from hydrolysis of ammonia borane and hydrazine borane is reported here. The catalyst is prepared by simultaneous reduction of suitable cobalt and palladium ions by sodium borohydride in the presence of poly($N$-vinyl-2-pyrrolidone) as a stabilizer. They are characterized by UV-Vis spectroscopy, TEM analysis, X-ray diffraction, and X-ray photoelectron spectroscopy. They provide average turnover frequencies of 30 min$^{-1}$ and 45 min$^{-1}$ in the hydrolysis of ammonia borane and hydrazine borane. They also provide activation energies of …
Improvement Of Electrochemical And Structural Properties Of Polycarbazole By Simultaneous Electrodeposition Of Chitosan, Di̇dem Balun Kayan, Veysel Polat
Improvement Of Electrochemical And Structural Properties Of Polycarbazole By Simultaneous Electrodeposition Of Chitosan, Di̇dem Balun Kayan, Veysel Polat
Turkish Journal of Chemistry
Polycarbazole/chitosan composite materials were synthesized electrochemically at various loadings of chitosan (Chi). Their electrochemical, structural, thermal, and morphological characterizations were investigated by cyclic voltammetry, chronoamperometry, electrochemical impedance spectroscopy, Fourier transform infrared spectroscopy, thermal gravimetry, and scanning electron microscopy. Further electrical conductivity was measured using a four-point probe technique. The electrochemical results showed that the electrical conductivity of the polymeric composite film was increased by increasing the amount of Chi in the electrolyte medium. The as-prepared composite films exhibited enhanced electrical conductivity and structural properties of polycarbazole due to the presence of Chi in the composite films.
Spectrophotometric Determination Of Carmoisine After Cloud Point Extraction Using Triton X-114, Aslihan Karatepe, Çağri Akalin, Mustafa Soylak
Spectrophotometric Determination Of Carmoisine After Cloud Point Extraction Using Triton X-114, Aslihan Karatepe, Çağri Akalin, Mustafa Soylak
Turkish Journal of Chemistry
Carmoisine (E122) is a synthetic azo dye that is generally used to give a red color to food products. In this work, a sensitive and simple method was developed for the determination of carmoisine based on cloud point extraction. To obtain the optimum conditions for the extraction efficiency of carmoisine, the effects of different analytical parameters such as H$_{2}$SO$_{4}$ concentration, concentration of Triton X-114, and equilibrium temperature were studied. The calibration graph was linear between 0.05 and 5.0 $\mu $g/mL and the detection limit based on three times the standard deviation of the blank was 7.2 $\mu $g/L. The method …
Investigation Of Solvent Effect On Photophysical Properties Of Some Sulfonamides Derivatives, Ebru Bozkurt, Hali̇se İnci̇ Gül, Mehtap Tuğrak
Investigation Of Solvent Effect On Photophysical Properties Of Some Sulfonamides Derivatives, Ebru Bozkurt, Hali̇se İnci̇ Gül, Mehtap Tuğrak
Turkish Journal of Chemistry
The photophysical properties of new sulfonamides synthesized recently were investigated in different solvents. Shifts in the absorption and fluorescence spectra of both compounds (S10 and S11) occurred depending on the solvents used. Ground and excited state dipole moments of the molecules were calculated using the spectral shifts of the compounds in different solvents and polarity function of solvents, respectively. They were 1.32 and 1.46 D for S10 and 1.71 and 4.89 D for S11. These results suggested that the excited state dipole moments are greater than those in ground state for both molecules. This means that the dyes were more …
Activity Of $\Gamma $-Al$_{2}$O$_{3}$-Based Mn, Cu, And Co Oxide Nanocatalysts For Selective Catalytic Reduction Of Nitric Oxide With Ammonia, Parvaneh Nakhostin Panahi, Gerard Delahay
Activity Of $\Gamma $-Al$_{2}$O$_{3}$-Based Mn, Cu, And Co Oxide Nanocatalysts For Selective Catalytic Reduction Of Nitric Oxide With Ammonia, Parvaneh Nakhostin Panahi, Gerard Delahay
Turkish Journal of Chemistry
Our studies on the selective catalytic reduction of NO (SCR-deNO) properties of M/$\gamma $-Al$_{2}$O$_{3}$ (M = Mn, Co, Cu) nanocatalysts are presented. All catalysts were prepared by homogeneous deposition precipitation using urea as the precursor for the precipitating agent. The SCR activity followed the order Mn/$\gamma $-Al$_{2}$O$_{3} >$ Cu/$\gamma $-Al$_{2}$O$_{3} >$ Co/$\gamma $-Al$_{2}$O$_{3}$. The nanocatalysts were characterized with respect to their texture (N$_{2}$-BET), particle size (TEM), reducibility (H$_{2}$-TPR), and acidity (NH$_{3}$-TPD). The TEM analysis revealed that the metal species have superior dispersion with less agglomeration and sintering on $\gamma $-Al$_{2}$O$_{3}$ support. The H$_{2}$-TPR results confirmed that the Mn/$\gamma $-Al$_{2}$O$_{3}$ nanocatalyst …
Efficient Multicomponent Synthesis Of 1,2,3-Triazoles Catalyzed By Cu(Ii) Supported On Pei@Fe$_{3}$O$_{4}$ Mnps In A Water/Peg$_{300}$ System, Zeinab Hassanpour, Aziz Maleki, Morteza Hosseini, Lena Gorgannezhad, Vajihe Nejadshafiee, Ali Ramazani, Ismaeil Haririan, Abbas Shafiee, Mehdi Khoobi
Efficient Multicomponent Synthesis Of 1,2,3-Triazoles Catalyzed By Cu(Ii) Supported On Pei@Fe$_{3}$O$_{4}$ Mnps In A Water/Peg$_{300}$ System, Zeinab Hassanpour, Aziz Maleki, Morteza Hosseini, Lena Gorgannezhad, Vajihe Nejadshafiee, Ali Ramazani, Ismaeil Haririan, Abbas Shafiee, Mehdi Khoobi
Turkish Journal of Chemistry
A highly dispersible and magnetically recoverable Cu-PEI@Fe$_{3}$O$_{4}$ MNPs catalyst was prepared and successfully applied in one-pot three-component coupling of terminal alkynes, sodium azide, and alkyl bromides/chlorides in water to give 1,4-disubstituted 1,2,3-triazoles with good to excellent yields. The catalyst was fully characterized with FT-IR, TGA, TEM, SEM, VSM, EDX, cyclic voltammetry, and ICP-AES spectroscopic techniques. Furthermore, the catalyst was easily recycled by an external magnet and successfully reused six times in the reaction without significant loss of its catalytic activity and copper leaching. The large-scale reaction was also carried out in the absence of any base and reducing agent even …
Synthesis And Photovoltaic Characterization Of Triarylamine-Substituted Quinoxaline Push-Pull Dyes To Improve The Performance Of Dye-Sensitized Solar Cells, Kadi̇r Demi̇rak, Mustafa Can, Ci̇han Özsoy, Mesude Zeli̇ha Yi̇ği̇t, Burak Gülteki̇n, Şerafetti̇n Demi̇ç, Ceylan Zafer
Synthesis And Photovoltaic Characterization Of Triarylamine-Substituted Quinoxaline Push-Pull Dyes To Improve The Performance Of Dye-Sensitized Solar Cells, Kadi̇r Demi̇rak, Mustafa Can, Ci̇han Özsoy, Mesude Zeli̇ha Yi̇ği̇t, Burak Gülteki̇n, Şerafetti̇n Demi̇ç, Ceylan Zafer
Turkish Journal of Chemistry
Novel unsymmetrical organic sensitizers having donor, $\pi $-spacer, and anchoring groups were designed and synthesized for dye-sensitized solar cell (DSSC) application. The dyes 3-{4-[7-(4-{bis[4-(hexyl)phenyl]amino} phenyl)-11,12-dibutoxy-1,4,5,8-tetrahydrodibenzo [a, c] phenazine-2-yl]phenyl} -2-cyano acrylic acid (KD-148) and 3-{5-[7-(4-{bis[4-(hexyloxy)phenyl]amino} phenyl)-11,12-dibutoxy-1,4,5,8-tetrahydrodibenzo [a, c] phenazine-2-yl]-2-thienyl} -2-cyano acrylic acid (KD-150) were anchored onto TiO$_{2}$ and tested with ionic liquid electrolyte. The monochromatic incident photon-to-current conversion efficiencies (IPCE) of the dyes were 50% and 60% at 420 nm, respectively. The KD-150-sensitized solar cell gave a short-circuit current (I$_{SC})$ of 7.37 mA/cm$^{2}$, an open-circuit voltage (V$_{oc})$ of 560 mV, a fill factor (FF) of 0.56, and overall conversion efficiency ($\eta …
The Structure And Cytotoxic Activity Of A New Saponin: Cephoside A From Cephalaria Elazigensis Var. Purpurea, Peyker Kayce, Nazli Boke Sarikahya, Murat Pekmez, Nazli Arda, Suheyla Kirmizigul
The Structure And Cytotoxic Activity Of A New Saponin: Cephoside A From Cephalaria Elazigensis Var. Purpurea, Peyker Kayce, Nazli Boke Sarikahya, Murat Pekmez, Nazli Arda, Suheyla Kirmizigul
Turkish Journal of Chemistry
Investigation of the aerial parts of Cephalaria elazigensis var. purpurea afforded one new oleanane-type saponin, namely cephoside A (1), and five known natural compounds (2-6). Compound 2, named anemoclemoside A, which is an unusual triterpene glycoside, was identified in the family Dipsacaceae for the first time. Chemical structures of all compounds were determined on the basis of the HRESIMS and 1D and 2D NMR data. Cephoside A (1) and anemoclemoside A (2) were assessed for their cytotoxic activities against HeLa cells, having IC$_{50}$ values of 495 and 135 $\mu $g/mL, respectively.
Synthesis, Characterization, And Antimicrobial Activities Of Novel Monosaccharide-Containing Schiff Base Ligands, Fatma Telli̇, Stephen Thomas Astley, Azi̇ze Yeşi̇m Salman
Synthesis, Characterization, And Antimicrobial Activities Of Novel Monosaccharide-Containing Schiff Base Ligands, Fatma Telli̇, Stephen Thomas Astley, Azi̇ze Yeşi̇m Salman
Turkish Journal of Chemistry
Four new chiral Schiff base ligands (3a-4a, 3b-4b) have been prepared using aminoisopropylidene derivatives of glucose and aminochloralose derivatives of mannose. The synthesized compounds 1 and 2 were characterized by nuclear magnetic resonance ($^{1}$H and $^{13}$C NMR), Fourier transform infrared spectroscopy (FTIR), UV/visible spectroscopy, and elemental analysis. A total of eight Schiff base compounds (3a-6a, 3b-6b) were tested for antimicrobial activity against Escherichia coli ATCC 12228, Staphylococcus aureus ATCC 6538, Klebsiella pneumoniae CCM 2318, Pseudomonas aeruginosa ATCC 27853, Salmonella typhimurium CCM 5445, Enterococcus faecalis ATCC 29212, Bacillus subtilis ATCC 6633, and Candida albicans ATCC 10239 and exhibited a range of …
Fabrication Of Multilayer Graphene Oxide-Reinforced High Density Polyethylene Nanocomposites With Enhanced Thermal And Mechanical Properties Via Thermokinetic Mixing, Burcu Saner Okan
Turkish Journal of Chemistry
High density polyethylene (HDPE) was compounded with thermally exfoliated graphene oxide (TEGO) by thermokinetic mixing in a short time. High shear rates during the compounding process provided high exfoliation and proper dispersion of graphene layers in the polymer matrix. Different TEGO/polymer ratios were used to get efficient melt mixing. Structural analysis by spectroscopic techniques confirmed the exfoliation of TEGO sheets and the coverage of their surfaces by HDPE chains. Furthermore, homogeneous dispersion of graphene sheets in the matrix led to the enhancement in the mechanical and thermal properties of HPDE-based nanocomposites. Especially stress concentration sites were significantly reduced by preventing …
Efficient Photodegradation Of Neutral Red Chloride Dye In Aqueous Medium Using Graphene/Cobalt-Manganese Oxides Nanocomposite, Khalid Saeed, Idrees Khan
Efficient Photodegradation Of Neutral Red Chloride Dye In Aqueous Medium Using Graphene/Cobalt-Manganese Oxides Nanocomposite, Khalid Saeed, Idrees Khan
Turkish Journal of Chemistry
Graphene/cobalt-manganese oxides nanocomposites were prepared from their precursor through chemical reduction where NaOH was used as a reducing agent. The obtained GNs/Co-Mn nanocomposites were used as photocatalyst for the photodegradation of Neutral Red Chloride (NRC) dye in aqueous solution under sunlight as a function of time and catalyst dosage. The morphology and photodegradation study was carried out using scanning electron microscopy (SEM) and UV-VIS spectrophotometry, respectively. The SEM image showed the presence of Co-Mn nanoparticles on the surface of GNs, which were also confirmed by energy dispersive X-ray analysis. The photodegradation study of NRC showed that the degradation of dye …
Bis(Indoline-2,3-Diones): Versatile Precursors For Novel Bis(Spirooxindoles) Incorporating 4$H$-Chromene-3-Carbonitrile And Pyrano[2,3-$D$]Pyrimidine-6-Carbonitrile Derivatives, Said Ahmed Soliman Ghozlan, Muhammed Aly Ramadan, Amr Mohmed Abdelmoniem, Ahmed H. M. Elwahy, Ismail Abdelshafy Abdelhamid
Bis(Indoline-2,3-Diones): Versatile Precursors For Novel Bis(Spirooxindoles) Incorporating 4$H$-Chromene-3-Carbonitrile And Pyrano[2,3-$D$]Pyrimidine-6-Carbonitrile Derivatives, Said Ahmed Soliman Ghozlan, Muhammed Aly Ramadan, Amr Mohmed Abdelmoniem, Ahmed H. M. Elwahy, Ismail Abdelshafy Abdelhamid
Turkish Journal of Chemistry
Multicomponent reaction of dimedone or 1,3-dimethylbarbituric acid and malononitrile with a series of bis(indoline-2,3-diones) afforded the corresponding bis(2-amino-7,7-dimethyl-2',5-dioxo-5,6,7,8-tetrahydrospiro[chromene-4,3'-indoline]-3-carbonitrile) and bis(7'-amino-1',3'-dimethyl-2,2',4'-trioxo-1',2',3',4'-tetrahydrospiro[indoline-3,5'-pyrano [2,3-d]pyrimidine]-6'-carbonitrile) derivatives in good to excellent yield.
A Rapid, Eco-Friendly, And Reliable Microplate Method For Determination Of Cr(Vi), Alejandro Coreño Alonso, Gustavo Cruz Jimenez, Leticia Lopez Martinez, Georgina Elena Reyna Lopez, Francisco Javier Acevedo Aguilar
A Rapid, Eco-Friendly, And Reliable Microplate Method For Determination Of Cr(Vi), Alejandro Coreño Alonso, Gustavo Cruz Jimenez, Leticia Lopez Martinez, Georgina Elena Reyna Lopez, Francisco Javier Acevedo Aguilar
Turkish Journal of Chemistry
In the present work, the reaction of Cr(VI) with 1,5-diphenylcarbazide in microplates (enzyme-linked immunosorbent assay microtiter plate) and a subsequent determination in a plate reader at 540 nm were performed. The final volume utilized for each determination was 200 $\mu $L, and the cost and waste were reduced for hexavalent chromium [Cr(VI)] quantification. The use of microplates allowed for the analysis of a large number of samples, reducing analysis time. No statistically significant differences were observed between the results obtained in the analysis of Cr(VI) in real samples by the conventional procedure and by the proposed methodology in this work …
Synthesis Of Na-, Fe-, And Co-Promoted Tio$_{2}$/Multiwalled Carbon Nanotube Composites And Their Use As A Photocatalyst, Alp Yürüm, Gürkan Karakaş
Synthesis Of Na-, Fe-, And Co-Promoted Tio$_{2}$/Multiwalled Carbon Nanotube Composites And Their Use As A Photocatalyst, Alp Yürüm, Gürkan Karakaş
Turkish Journal of Chemistry
The use of multiwalled carbon nanotubes (CNTs) in sol-gel synthesized titanium dioxide (TiO$_{2})$ photocatalysts as templates was systematically studied. CNTs have high oxidative thermal stability and the controlled removal of CNTs can be achieved at lower temperatures under air flow by the use of Na, Fe, and Co as a catalyst. These catalysts helped to reduce the oxidation temperature of CNTs; thus anatase phase was achieved without significant sintering. The use of a promoter, heat treatment, and various heat treatment atmospheres was effective in specific surface area, crystallinity, and photocatalytic activity against methylene blue (MB) degradation. While the specific surface …
A Biochar-Modified Carbon Paste Electrode, Derya Bal Altuntaş, Gökçen Akgül, Jale Yanik, Ülkü Anik
A Biochar-Modified Carbon Paste Electrode, Derya Bal Altuntaş, Gökçen Akgül, Jale Yanik, Ülkü Anik
Turkish Journal of Chemistry
The present work examıned the use of biochar derived from tea waste as a novel electrode material. For the fabrication of the biochar electrode, suitable amounts of biochar and graphite were mixed with mineral oil for the first time. The electrochemical performance of the biochar-modified carbon paste electrode (BCPE) was measured by various cyclic voltammetric reactions for several redox systems. The factors affecting the electrode kinetics of BCPE surfaces were examined and optimized. The BCPE was applied as transducer in a glucose biosensor. The results reflect the effective properties of composite electrodes and the electrochemical properties of biochar showing that …
Singlet Oxygen Generation From Poly[4-Diacetoxyiodo]Styrene And Hydrogen Peroxide, Mustafa Çatir
Singlet Oxygen Generation From Poly[4-Diacetoxyiodo]Styrene And Hydrogen Peroxide, Mustafa Çatir
Turkish Journal of Chemistry
Treatment of hydrogen peroxide with a polymer-supported hypervalent iodine compound, poly[4-diacetoxyiodo] styrene (PDAIS), generates singlet molecular oxygen ($^{1}$O$_{2})$. Singlet oxygen generation was proved by trapping with typical organic compounds such as conjugated dienes, aromatic dienes, and electron-rich alkene. When compared to monomer analogue, the use of PDAIS in peroxidation of substrates gave slightly better yields (45%-96%). Regeneration and reuse of PDAIS showed similar activity. The mechanism underlying generation of singlet oxygen and reaction scope was examined.
Synthesis Of Neodymium-Iron Nanoperovskite For Sensing Applications Of An Antiallergic Drug, Nada F. Atta, Mohammad H. Binsabt, Ekram H. El-Ads, Ahmed Galal
Synthesis Of Neodymium-Iron Nanoperovskite For Sensing Applications Of An Antiallergic Drug, Nada F. Atta, Mohammad H. Binsabt, Ekram H. El-Ads, Ahmed Galal
Turkish Journal of Chemistry
A facile route was used for the fabrication of NdFeO$_{3}$ (NF) perovskite. The orthorhombic structure of single phase nanocrystalline NdFeO$_{3}$ perovskite was confirmed by different characterization techniques: XRD, FTIR, TEM, BET, SEM, and EDAX. The nanoperovskite was successfully used as a sensor component with a carbon paste electrode (CpE) for the determination of ketotifen in pharmaceutical formulations. Ketotifen, an antiallergic drug, is utilized for the treatment of asthma attacks, rhinitis, skin allergies, and anaphylaxis. Sodium dodecyl sulfate (SDS) was employed in a surface assembly mode to improve the sensitivity of the sensor response. The proposed sensor, NdFeO$_{3}$ in situ modified …
Calix[4]Pyrroles With Bulky Substituents And Their Anion Binding Studies, Ahmet Akar, Abdullah Aydogan
Calix[4]Pyrroles With Bulky Substituents And Their Anion Binding Studies, Ahmet Akar, Abdullah Aydogan
Turkish Journal of Chemistry
Calix[4]pyrrole derivatives with bulky substituents at their meso-positions were synthesized via mixed condensation of pyrrole with cyclohexanone and acetophenone derivatives. Anion binding studies, carried out by isothermal titration calorimetry in 1,2-dichloroethane with Cl$^{-}$ and CH$_{3}$CO$_{2}^{-}$ anions in the form of their tetrabutylammonium salts, revealed that these new calix[4]pyrrole derivatives can bind the aforementioned anions as effectively as the unsubstituted ''parent'' system, octamethylcalix[4]pyrrole (1). Structural characterizations of new calix[4]pyrroles were carried out by using $^{1}$H and $^{13}$C NMR spectroscopy corroborated with mass spectrometry.
Diastereoselective Synthesis Of Novel 2,5-Dioxopyrrolidine Derivatives Via Biocatalytic Domino Reactions, Saadieh Mohajer, Robabeh Baharfar
Diastereoselective Synthesis Of Novel 2,5-Dioxopyrrolidine Derivatives Via Biocatalytic Domino Reactions, Saadieh Mohajer, Robabeh Baharfar
Turkish Journal of Chemistry
A series of novel 2,5-dioxopyrrolidines were synthesized by the one-pot reaction of coumarin-3-carboxylic acids 1 with thiourea derivatives and alkyl isocyanides in the presence of Fe$_{3}$O$_{4}$ NPs @ lipase as heterogeneous reusable nanobiocatalysts with high yields.
Synchrotron X-Ray Diffraction Studies Of $\Beta $-Ca$_{2-X}M_{X}$Sio$_{4}$ ($M$ = Mg And Sr), Anti Prodjosantoso, Brendan Kennedy
Synchrotron X-Ray Diffraction Studies Of $\Beta $-Ca$_{2-X}M_{X}$Sio$_{4}$ ($M$ = Mg And Sr), Anti Prodjosantoso, Brendan Kennedy
Turkish Journal of Chemistry
The structures of Mg- and Sr-doped $\beta $-Ca$_{2}$SiO$_{4}$ have been established from high-resolution synchrotron X-ray powder diffraction. These silicates are all isostructural and the structures have been refined in the monoclinic space group, $P$2$_{1}$/$n$. As expected based on size arguments, the cell parameters increase as the amount of Sr increases and likewise decrease as the amount of Mg increases due the size effects of the dopant cation. In all cases the SiO$_{4}$ tetrahedra are essentially regular.
Online Coupling Electrochemical Preconcentration And Gfaas Technique As Effective Method For Determination Of Ultratrace Concentrations Of Antimony In Groundwater And Surface Water Samples, Lubomir Machynak, Martin Nemecek, Ernest Beinrohr, Frantisek Cacho
Online Coupling Electrochemical Preconcentration And Gfaas Technique As Effective Method For Determination Of Ultratrace Concentrations Of Antimony In Groundwater And Surface Water Samples, Lubomir Machynak, Martin Nemecek, Ernest Beinrohr, Frantisek Cacho
Turkish Journal of Chemistry
The present article describes a method of determination of low antimony concentrations using a graphite furnace AAS technique after electrochemical preconcentration. A 2-electrode flow-through cell was developed with a working electrode made of gold-coated porous carbon and an accessory Pt electrode. This cell worked in online coupling with the graphite furnace atomizer. Accumulation occurred from the 6 M hydrochloric acid solution and 2 M nitric acid was used to dissolve and transport antimony into the sampling loop. The sampling loop was placed on a 6-way valve. The preconcentrated solution was transported to the atomizer using an air jet. The detection …
A Rapid, Efficient, And Green Synthesis Of Benzo[$A$]Chromeno[2,3-$C$]Phenazine Derivatives Via Microwave Assistance And Dabco~Catalyzed A Novel Domino Cyclization, Seid-Ali Mirmiran-Yazdi, Afshin Yazdani Elah Abadi, Nasim Shams, Razieh Mohebat
A Rapid, Efficient, And Green Synthesis Of Benzo[$A$]Chromeno[2,3-$C$]Phenazine Derivatives Via Microwave Assistance And Dabco~Catalyzed A Novel Domino Cyclization, Seid-Ali Mirmiran-Yazdi, Afshin Yazdani Elah Abadi, Nasim Shams, Razieh Mohebat
Turkish Journal of Chemistry
An efficient, convenient, and environmentally benign procedure for the synthesis of novel benzo[$a$]chromeno[2,3-$c$]phenazine derivatives has been developed by domino four-component condensation reaction between 2-hydroxynaphtha- lene-1,4-dione, $o-$phenylenediamine, aromatic aldehydes, and naphthols or phenol in the presence of a catalytic amount of DABCO as an expedient, ecofriendly, and reusable base catalyst under microwave irradiation in EtOH/H$_{2}$O (1:1). This green process produces biologically and pharmacologically significant heterocycles in a single one-pot operation and offers considerable advantages such as operational simplicity, short reaction time, high yields, reusability of the catalyst, absence of any tedious workup or purification, and avoidance of hazardous reagents/solvents.
Decolorization Of Reactive Orange 16 Via Ferrate(Vi) Oxidation Assisted By Sonication, Serkan Şahi̇nkaya
Decolorization Of Reactive Orange 16 Via Ferrate(Vi) Oxidation Assisted By Sonication, Serkan Şahi̇nkaya
Turkish Journal of Chemistry
The decolorization of azo dye C.I. reactive orange 16 (RO 16) via ferrate(VI) and sono-ferrate(VI) methods, which is the combination of the ferrate(VI) oxidation method with sonication, has been achieved in the present study. The influences of some important operating parameters, which are the initial pH, the concentration of potassium ferrate(VI) (K$_{2}$FeO$_{4})$ and the RO 16 dye, and ultrasonic density (for only the sono-ferrate(VI) method), on the color removal have been investigated. The optimum conditions have been determined as pH = 7 and [K$_{2}$FeO$_{4}$] = 50 mg L$^{-1}$ for the individual ferrate(VI) oxidation method and pH = 7 and [K$_{2}$FeO$_{4}$] …