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Articles 1801 - 1830 of 2628
Full-Text Articles in Physical Sciences and Mathematics
Synthesis, Characterization, And Biocidal Studies Of The Newly Synthesized Di- And Triorganotin(Iv) Complexes With N-Butylhydrogen Phthalate, Sadiq-Ur Rehman, Saqib Ali, Saira Shahzadi, Abdul Malik, Ejaz Ahmed
Synthesis, Characterization, And Biocidal Studies Of The Newly Synthesized Di- And Triorganotin(Iv) Complexes With N-Butylhydrogen Phthalate, Sadiq-Ur Rehman, Saqib Ali, Saira Shahzadi, Abdul Malik, Ejaz Ahmed
Turkish Journal of Chemistry
Di-(1, 3, 8) and triorganotin(IV) complexes (2, 5, 7) with the general formula R_nSnL_{4-n}, where R = Me, Et, n-Bu, n-Oct, Ph, and Bz, and L = the n-C_4H_9OCOC_6H_4COO^- monoanionic ligand have been synthesized by the reaction of the silver salt of the n-butylhydrogen phthalate with di- and triorganotin chloride in dry chloroform. However, di-n-butyl- and di-n-octyltin(IV) derivatives (4 and 6, respectively) were synthesized by the reaction of the corresponding organotin(IV) oxide with n-butylhydrogen phthalate in dry toluene. All the synthesized complexes were characterized by elemental analysis, FT-IR, multinuclear (^1H, ^{13}C, ^{119}Sn) NMR, and mass spectrometric techniques to assess the …
Convergent Synthesis Of Fluorinated Dendrons Using The Mesylate Activation Route, Özgür Altan Bozdemi̇r, Meltem Di̇lek, Mehmet Tutaş
Convergent Synthesis Of Fluorinated Dendrons Using The Mesylate Activation Route, Özgür Altan Bozdemi̇r, Meltem Di̇lek, Mehmet Tutaş
Turkish Journal of Chemistry
In this paper we describe an alternative route for the preparation of dendrons bearing fluoro aryl functionalities at the periphery using mesylate activation. p-Fluorobenzyl bromide and perfluorobenzyl bromide were used to introduce the p-fluoro and perfluorobenzyl moieties at the periphery of dendrons. 3,5-Dihydroxybenzyl alcohol was used as the repeating unit of the dendrons. In this convergent approach, the Williamson ether synthesis technique was used as the generation enhancement step. Second generation mono- and perfluorobenzyl alcohol dendrons were obtained from active mesylate precursors. This mesylate activation method has the advantage of short reaction times in the subsequent steps and avoids chromatographic …
Benzimidazolylidene Carbene Ligated Palladium Catalysis Of The Heck Reaction In Aqueous Media, İsmai̇l Özdemi̇r, Yetki̇n Gök, Nevi̇n Gürbüz, Beki̇r Çeti̇nkaya
Benzimidazolylidene Carbene Ligated Palladium Catalysis Of The Heck Reaction In Aqueous Media, İsmai̇l Özdemi̇r, Yetki̇n Gök, Nevi̇n Gürbüz, Beki̇r Çeti̇nkaya
Turkish Journal of Chemistry
A highly effective, easy to handle and environmentally benign process for a palladium mediated Heck reaction was developed. The in situ prepared 3-component system, Pd(OAc)_2 / 1,3-dialkylbenzimidazolium chlorides (LHX = 1a-g) and Cs_2CO_3, catalyzes quantitatively the Heck coupling of aryl bromides under mild conditions in aqueous media.
Fragmentation Of Xe^{129} In The Liquid-Gas Phase Transition Region, Mehmet Erdoğan, Ni̇hal Büyükçi̇zmeci̇, Riza Oğul
Fragmentation Of Xe^{129} In The Liquid-Gas Phase Transition Region, Mehmet Erdoğan, Ni̇hal Büyükçi̇zmeci̇, Riza Oğul
Turkish Journal of Chemistry
We analyzed the fragmentation of the Xe^{129} nucleus to determine the effects of surface and symmetry energies on the fragment distribution on the basis of the statistical multifragmentation model. Relative yields of fragments were classified with respect to the mass number of the fragments in the transition region. It was found that the symmetry energy of the hot fragments produced in the statistical freeze-out is very important for isotope distributions. However, its influence on the mean fragment mass distributions is negligible. On the other hand, it was demonstrated that surface energy significantly influences the fragment distribution while the symmetry energy …
Selenium And Trace Element Distribution In Astragalus Plants: Developing A Differential Pulse Polarographic Method For Their Determination, Güler Somer, A. Cengi̇z Çalişkan
Selenium And Trace Element Distribution In Astragalus Plants: Developing A Differential Pulse Polarographic Method For Their Determination, Güler Somer, A. Cengi̇z Çalişkan
Turkish Journal of Chemistry
Astragalus plants have a wide range of applications in pharmaceuticals (gum tragacanth), as thickening agents in foods, and may have applications in controlling cancer cells. They are used as feed for animals and they are indicator plants for selenium. Because of their use in health-related areas it is very important to determine their selenium and trace element content with high accuracy. A new differential pulse polarographic method was established for trace element determination (10 elements) and their distribution in these plants. The Astragalus plants investigated in this work are Astragalus microcephalus and Astragalus lusitanicus, which grow almost everywhere. Their roots, …
N,N`-Bis(1`-Hydroxy-2`-Acetonaphthone)Propylenediamine: Synthesis, Extractive Properties, And Use As An Ionophore In A Cu(Ii)-Selective Potentiometric Sensor, Daryoush Emadi, Mohammad Reza Yaftian, Saeed Rayati
N,N`-Bis(1`-Hydroxy-2`-Acetonaphthone)Propylenediamine: Synthesis, Extractive Properties, And Use As An Ionophore In A Cu(Ii)-Selective Potentiometric Sensor, Daryoush Emadi, Mohammad Reza Yaftian, Saeed Rayati
Turkish Journal of Chemistry
The binding ability of N,N'-bis(1'-hydroxy-2'-acetonaphthone)propylenediimine (H_2L) towards metal ions was investigated by performing liquid-liquid extraction experiments to extract Cu^{2+}, Ni^{2+}, Co^{2+}, and Zn^{2+} ions from nitrate solutions. Extraction takes place by a cation exchange mechanism and the ligand shows a pronounced selectivity towards Cu^{2+} ions. Conventional log-log analysis of the extraction data reveals that the Cu^{2+} ions are extracted by a 1:1 (metal to ligand) complex formation. The effect of parameters influencing the extraction process, such as type of diluent and concentration of electrolyte in the aqueous phase, has been studied. The selectivity of the ligand was evaluated by competitive …
A New Alkaloid From Isatis Costata, Itrat Fatima, Itrat Anis, Ijaz Ahmad, Abdul Malik, Nighat Afza
A New Alkaloid From Isatis Costata, Itrat Fatima, Itrat Anis, Ijaz Ahmad, Abdul Malik, Nighat Afza
Turkish Journal of Chemistry
A new alkaloid has been isolated from Isatis costata C.A.Mey. and assigned structure 1 on the basis of spectroscopic data including 1D and 2D NMR techniques. Methyl 2-acetoamidobenzoate (2), \beta-sitosterol (3), and ursolic acid (4) were also isolated for the first time from this species.
Pvc-Membrane Electrodes Based On 18-Crown-6 And Dibenzo-18-Crown-6 Ethers For Determination Of Silver, Mohsen Mousa Zareh, Magda A. Akl, Ahmd Khlil Gohneim, Mohmed Hussin Abd El-Aziz
Pvc-Membrane Electrodes Based On 18-Crown-6 And Dibenzo-18-Crown-6 Ethers For Determination Of Silver, Mohsen Mousa Zareh, Magda A. Akl, Ahmd Khlil Gohneim, Mohmed Hussin Abd El-Aziz
Turkish Journal of Chemistry
PVC-membrane electrodes for Ag^+ based on either 18-crown-6 (I) or di-benzo-18-crown-6 ether (II) were applied for the first time. The effect of solvent mediator on the electrode performance was discussed. Nernstian slope values were 59 and 58.9 mV/decade for both I and II electrode types, respectively. The linear concentration range was 10^{-5}-10^{-1}M. The detection limit was 7.9 \times 10^{-6} M. The working pH ranges were 5-9 or 4-9, depending on the concentration of Ag^+ ion. The electrodes showed good selectivity towards most of the common alkali, alkaline earths, and transition metal cations. The electrodes were applied successfully for the determination …
A Novel Degradable Adsorbent Of The Hyperbranched Aliphatic Polyester Grafted Cellulose For Heavy Metal Ions, Peng Liu
Turkish Journal of Chemistry
A novel degradable adsorbent for the removal of heavy metal ions from waste water, a hyperbranched aliphatic polyester grafted cellulose (HAPE-Cell), was successfully prepared by the simple one-pot method for the first time. The hyperbranched aliphatic polyester was grafted from the surface hydroxyl groups of natural cotton fibers via the solution polycondensation of the AB_2 monomer, 2, 2-bis(hydroxymethyl)propionic acid (bis-MPA), with the catalysis of p-toluenesulfonic acid (p-TSA). The HAPE-Cell was characterized by elemental analysis, Fourier transform infrared (FT-IR) spectroscopy, X-ray diffraction (XRD), and scanning electron microscopy (SEM). The adsorption properties of the HAPE-Cell towards the heavy metal ions (Cu(II), Hg(II), …
Role Of Tridentate Schiff Base And Methoxyethylindenyl Derivatives Of Lanthanocene Complexes For The Synthesis Of High Molecular Weight Polymethyl Methacrylate (Pmma), Muhammad Yousaf, Aftab Ahmad Chatha, Abdul Jabbar, H. Badaruddin Ahmad, Ameer Fawad Zahoor, Muhammad Kaleem Khosa, Syed Sarwar Alam
Role Of Tridentate Schiff Base And Methoxyethylindenyl Derivatives Of Lanthanocene Complexes For The Synthesis Of High Molecular Weight Polymethyl Methacrylate (Pmma), Muhammad Yousaf, Aftab Ahmad Chatha, Abdul Jabbar, H. Badaruddin Ahmad, Ameer Fawad Zahoor, Muhammad Kaleem Khosa, Syed Sarwar Alam
Turkish Journal of Chemistry
Different mixed ligand lanthanocene complexes along with Al(i-Bu)_3 are capable of synthesizing partially syndiotactic high molecular weight polymethylmethacrylate. The Schiff base derivative of mixed ligand lanthanocene complexes (1-4) showed better efficiency (Mv = 227 \times 10^3-354 \times 10^3) compared to the methoxyethylindenyl derivative of mixed ligand lanthanocene complexes (5-9) (Mv = 72 \times 10^3, 172 \times 10^3). The effects of the catalyst, temperature, catalyst/MMA molar ratio, and catalyst/Al(i-Bu)_3 molar ratio on the polymerization of MMA at 60 °C suggested that ligand size and radius of rare earth metals play an important role in determining the activity of the catalyst.
Development Of A New Set Of Additive Parameters For The Estimation Of Geometrical Distortion Of Cycloalkanes From C-13 Nmr Chemical Shifts, Emad A. S. Al-Hyali
Development Of A New Set Of Additive Parameters For The Estimation Of Geometrical Distortion Of Cycloalkanes From C-13 Nmr Chemical Shifts, Emad A. S. Al-Hyali
Turkish Journal of Chemistry
A previous model for the calculation of C-13 chemical shifts is modified by replacement of 3 parameters representing the p-character of carbon atom in cyclic systems with a single parameter aiming for the development of a new set of parameters with a wide range of application for the calculation of C-13 NMR chemical shifts. The considered systems are cyclohexanes, trans decalins, and a number of hypothetical polycyclic 6-member ring hydrocarbons. The developed parameters include a combination of quantum mechanical and statistical methods. They are based on 2 factors: through bond (electronic) effect represented by the partial electronic charge on the …
The Synthesis Of 2-(Chloromethyl)-6-Hydroxy-2h-Pyran-3 (6h)-One Via Achmatowicz Rearrangement, Zuhal Gerçek
The Synthesis Of 2-(Chloromethyl)-6-Hydroxy-2h-Pyran-3 (6h)-One Via Achmatowicz Rearrangement, Zuhal Gerçek
Turkish Journal of Chemistry
Achmatowicz rearrangement was carried out with 2-chloro-1-(furan-2-yl) ethanol, which was synthesized starting from 1-(furan-2-yl) ethanone. It was shown that the oxidation of 2-chloro-1-(furan-2-yl) ethanol with m-CPBA produced 2-(chloromethyl)-6-hydroxy-2H-pyran-3 (6H)-one in good yield (70%).
A New Ursane-Type Triterpenoid From Salvia Santolinifolia, Zaher Ahmad, Sajid Mehmood, Rehana Ifzal, Abdul Malik, Nighat Afza, Mohammad Ashraf, Erum Jahan
A New Ursane-Type Triterpenoid From Salvia Santolinifolia, Zaher Ahmad, Sajid Mehmood, Rehana Ifzal, Abdul Malik, Nighat Afza, Mohammad Ashraf, Erum Jahan
Turkish Journal of Chemistry
Santolinoic acid (1), a new ursane-type triterpene was isolated from the chloroform soluble fraction of Salvia santolinifolia. Its structure was established as 2\alpha, 3\beta, 9\alpha-trihydroxyurs-12-en-28-oic acid on the basis of spectroscopic analysis, including high resolution mass spectroscopy, and 1- and 2-dimensional NMR techniques. The compound (1) showed inhibitory activity against the enzymes acetylcholinesterase and butyrylcholinesterase.
Synthesis And Cytotoxic Activity Of Platinum(Ii) And Platinum(Iv) Complexes With 2-Hydroxymethylbenzimidazole Or 5(6)-Chloro-2-Hydroxymethylbenzimidazole Ligands Against Mcf-7 And Hela Cell Lines, Semra Utku, Fatma Gümüş, Si̇bel Gür, Aykut Özkul
Synthesis And Cytotoxic Activity Of Platinum(Ii) And Platinum(Iv) Complexes With 2-Hydroxymethylbenzimidazole Or 5(6)-Chloro-2-Hydroxymethylbenzimidazole Ligands Against Mcf-7 And Hela Cell Lines, Semra Utku, Fatma Gümüş, Si̇bel Gür, Aykut Özkul
Turkish Journal of Chemistry
Four platinum(II) and 4 platinum(IV) complexes with the structures [PtL_2Cl_2], [PtL_2I_2], [PtL_2Cl_4], and [PtL_2Cl_2(OH)_2] (L = 5(6)-non/orchloro-substituted-2-hydroxymethylbenzimidazole ligands as ``non-leaving groups''), respectively, were synthesized and characterized by their elemental analyses, and IR and ^1H-NMR spectra. In vitro cytotoxic activities of the platinum(II) and platinum(IV) complexes were tested against the human MCF-7 (breast cancer) and HeLa (cervix cancer) cell lines using the cell culture method. In general, the platinum(II) complexes were more active than the corresponding platinum(IV) complexes. The complexes, which were found to be less active than cisplatin, exhibited cyctotoxicity comparable to carboplatin on the human MCF-7 and HeLa cell …
Activation Of Light Alkanes On Pure And Fe And Al Doped Silica Clusters: A Density Functional And Oniom Study, Mehmet Ferdi̇ Fellah, Işik Önal
Activation Of Light Alkanes On Pure And Fe And Al Doped Silica Clusters: A Density Functional And Oniom Study, Mehmet Ferdi̇ Fellah, Işik Önal
Turkish Journal of Chemistry
C-H bond activation was studied by use of density functional theory (DFT) and ONIOM calculations as implemented in Gaussian 2003 at the B3LYP level utilising 6-31G* as the basis set for Si, Al, and Fe atoms and 3-21G** as the basis set for O and H atoms. Relative energy profiles were determined for pure silica modeled by a Si_7O_{21} cluster and Fe and Al doped silica clusters via coordinate driving calculations. The activation barriers for C-H bond activation of methane and ethane decrease with the substitution of Fe on the silica surface, which theoretically demonstrates a favorable effect of Fe …
A Mechanistic Approach To Elucidate Ethanol Electro-Oxidation, Ni̇yazi̇ Alper Tapan
A Mechanistic Approach To Elucidate Ethanol Electro-Oxidation, Ni̇yazi̇ Alper Tapan
Turkish Journal of Chemistry
In order to elucidate the mechanism of ethanol oxidation, a simple cylindrical diffusion-surface reaction was developed on a platinum disk electrode. An ethanol electro-oxidation mechanism was proposed, in which electrochemical reactions proceed without adsorption of any electro-oxidation products (C2 type) on the surface. After the simulation of the proposed mechanism, it was seen that the model can explain ethanol electro-oxidation behavior without any surface CO formation. The simulation of the mechanism indicated that the formation of acetaldehyde through the oxidation of bulk ethanol is the rate determining step between 0.6 and 0.75 V vs. RHE. After 0.75 V vs. RHE, …
Kinetic Study Of Selective Co Oxidation Over Pt-Co-Ce/Al_2o_3 Catalyst In Hydrogen-Rich Streams, Göktuğ Nezi̇hi̇ Özyönüm, Ayşe Ni̇lgün Akin, Ramazan Yildirim
Kinetic Study Of Selective Co Oxidation Over Pt-Co-Ce/Al_2o_3 Catalyst In Hydrogen-Rich Streams, Göktuğ Nezi̇hi̇ Özyönüm, Ayşe Ni̇lgün Akin, Ramazan Yildirim
Turkish Journal of Chemistry
The kinetics of the selective CO oxidation was studied in a fixed-bed microreactor at atmospheric pressure over Pt-Co-Ce/Al_2O_3 catalyst, which was prepared using the incipient to wetness co-impregnation technique. Intrinsic kinetic data were obtained in the initial rate region using 8 different sets of CO and O_2 concentrations, each at 2 space times, i.e. 2 catalyst loadings, at 110 °C. The kinetic models based on elementary reaction steps were constructed and tested using nonlinear regression analysis with Levenberg-Marquardt algorithm. The alternative models proposed for the similar catalytic systems in the literature were also tested. It was found that Pt-Co-Ce/Al_2O_3 acts …
Low Temperature Co Oxidation Kinetics Over Activated Carbon Supported Pt-Sno_X Catalysts, Fatma Soyal Baltacioğlu, Berri̇n Gülyüz, Ahmet Erhan Aksoylu, Zeynep İlsen Önsan
Low Temperature Co Oxidation Kinetics Over Activated Carbon Supported Pt-Sno_X Catalysts, Fatma Soyal Baltacioğlu, Berri̇n Gülyüz, Ahmet Erhan Aksoylu, Zeynep İlsen Önsan
Turkish Journal of Chemistry
The kinetics of low temperature CO oxidation were studied over sequentially impregnated 1wt%Pt-0.25wt%SnO_x supported on HNO_3-oxidized activated carbon (AC3) using a wide range of CO (1-10 mol%) and O_2 (1-4 mol%) concentrations. Intrinsic kinetic data were obtained in the initial rates region at 383 K in the absence and presence of 5-45 mol% H_2 in the feed. A power-function rate expression with positive dependence on CO (0.96) and negative dependence on oxygen (--0.31) was obtained for the low temperature oxidation of CO. The effect of H_2 on CO oxidation rates was also investigated under similar conditions.
Direct Hydrothermal Synthesis Of Palladium-Incorporated Silicate-Structured Mesoporous Catalysts, Canan Şener, Ti̇mur Doğu, Gülşen Doğu
Direct Hydrothermal Synthesis Of Palladium-Incorporated Silicate-Structured Mesoporous Catalysts, Canan Şener, Ti̇mur Doğu, Gülşen Doğu
Turkish Journal of Chemistry
Pd-Si-structured novel mesoporous nanocomposite catalytic materials, having quite high Pd/Si ratios, were synthesized by an acidic direct hydrothermal synthesis route. The nanocomposite catalytic materials were then characterized by XRD, XPS, EDS, nitrogen adsorption, and SEM techniques. Unlike MCM-41, the XRD patterns indicated a rather wide d_{(100)} band at a 2\theta value of about 1.9. The materials, with very high Pd/Si wt ratios between 1.43 and 2.66, were synthesized and had BJH surface area values between 600 and 200 m^2/g. The pore size distributions of these materials were also quite narrow, indicating pores between 2 and 7 nm.
Direct Formation Of H_2o_2 From H_2 And O_2, Meltem Yildiz, Ayşe Ni̇lgün Akin
Direct Formation Of H_2o_2 From H_2 And O_2, Meltem Yildiz, Ayşe Ni̇lgün Akin
Turkish Journal of Chemistry
The direct combination of hydrogen and oxygen to form hydrogen peroxide in liquid media with prepared catalysts was carried out in a slurry reactor at atmospheric pressure and room temperature. An O_2/H_2 ratio of 2:1 with a 50 mL/min flow rate was used in these experiments. Catalyst activity measurements were tested by the iodometric titration method using KMnO_4. The results are discussed based on the effects of support material, catalyst preparation method, reaction time, and medium (type of halide and acid) on hydrogen peroxide yield in direct oxidation of hydrogen to produce hydrogen peroxide. Our results showed that the catalytic …
Kinetics Of Synthesis Of Isobutyl Propionate Over Amberlyst-15, Ali̇me İzci̇, Hali̇t Levent Hoşgün
Kinetics Of Synthesis Of Isobutyl Propionate Over Amberlyst-15, Ali̇me İzci̇, Hali̇t Levent Hoşgün
Turkish Journal of Chemistry
The esterification of propionic acid with isobutanol in the presence of Amberlyst-15 as a catalyst was studied. Isobutyl propionate synthesized in this reaction has the fragrance of rum and is used in the food industry. The experiments were carried out in a stirred batch reactor at temperatures from 318 K to 348 K. As a solvent, 1,4 dioxan was used. The effects of the amount of catalyst used, the reaction time, the stirring speed, and the reaction temperature on the synthesis of isobutyl propionate were investigated. It was observed that solid-liquid external mass transfer resistance resulting from various stirring speeds …
Preparation And Characterization Of Ordered Tio_2 Photocatalysts: Films And Mesoporous Structures, Orçun Ergün, Osman Karslioğlu, Ayşen Yilmaz, Deni̇z Üner
Preparation And Characterization Of Ordered Tio_2 Photocatalysts: Films And Mesoporous Structures, Orçun Ergün, Osman Karslioğlu, Ayşen Yilmaz, Deni̇z Üner
Turkish Journal of Chemistry
Two different ordered TiO_2 structures were prepared as sol-gel films coated on glass and as mesoporous structures in order to study the effect, in 2-D or in 3-D, of bulk size on photocatalytic activity. Multilayer TiO_2 films were coated on glass by the sol-gel dip coating method. The UV-VIS characteristics of the films, with respect to the number of coating layers, were monitored. UV-VIS measurements implied an ordered TiO_2 structure grown on ITO glass. The second approach involved loading TiO_2 in mesoporous SBA-15 powder. Ti-SBA-15 with Ti/Si (mole/mole) ratios between 0.05 and 0.30 were prepared and characterized by XRD and …
Investigation Of Biodiesel Production From Canola Oil Using Mg-Al Hydrotalcite Catalysts, Oğuzhan İlgen, İsmai̇l Di̇nçer, Meltem Yildiz, Ertan Alpteki̇n, Nezahat Boz, Mustafa Çanakçi, Ayşe Ni̇lgün Akin
Investigation Of Biodiesel Production From Canola Oil Using Mg-Al Hydrotalcite Catalysts, Oğuzhan İlgen, İsmai̇l Di̇nçer, Meltem Yildiz, Ertan Alpteki̇n, Nezahat Boz, Mustafa Çanakçi, Ayşe Ni̇lgün Akin
Turkish Journal of Chemistry
Biodiesel produced by the transesterification of vegetable oils is a promising alternative fuel to diesel because of limited fossil fuel resources and environmental concerns. The use of heterogeneous catalysts greatly simplifies the technological process by facilitating the separation of the post-reaction mixture. The purpose of the present work was to examine a heterogeneous catalyst, in particular, Mg-Al hydrotalcites, to produce methyl esters of canola oil. In this study, the transesterification of canola oil with methanol was studied in a heterogeneous system, using Mg-Al hydrotalcites as solid base catalysts. The results showed that methanol is the best alcohol for this reaction …
Deactivation Of A Co-Precipitated Co/Al_2o_3 Catalyst, Meltem Yildiz, Ayşe Ni̇lgün Akin
Deactivation Of A Co-Precipitated Co/Al_2o_3 Catalyst, Meltem Yildiz, Ayşe Ni̇lgün Akin
Turkish Journal of Chemistry
The effects of reaction temperature, feed ratio, space time, and CO percentage in feed on the deactivation conditions of a co-precipitated 36 wt% Co/Al_2O_3 catalyst in CO hydrogenation were investigated. Environmental-SEM-EDX and temperature-programmed reduction (TPR) studies were performed on used catalysts to investigate the effect of reaction conditions on catalyst deactivation. Intensive coke deposition on the catalyst was observed at a reaction temperature of about 573 K. Increasing the H_2/CO ratio also increased the catalyst activity. Methane formed as the main product at high H_2/CO ratios. Although catalyst activity did not change significantly during the 9-h reaction period at all …
Dielectric Behavior Of The Catalyst Zeolite Nay, Ertuğrul İzci̇, Ali̇me İzci̇
Dielectric Behavior Of The Catalyst Zeolite Nay, Ertuğrul İzci̇, Ali̇me İzci̇
Turkish Journal of Chemistry
Zeolites are crystalline hydrated aluminosilicates of alkaline and alkaline earth metals. The basic zeolite structure is an anionic frame of Si and Al T-atoms, which are tetrahedral and coordinated with oxygen atoms. The electrical properties of zeolites are of enormous technical importance due to their manifold applications as solid catalysts. Zeolite NaY was used in this investigation. Zeolite NaY is a synthetic zeolite and it has a faujasite structure. The electrical conductivity, dielectric permittivity, and loss factor of Na ion exchanged zeolite NaY was carried out in the 10^4-10^6 Hz frequency region at room temperature and different water contents using …
Alcohols As Alternatives To Petroleum For Environmentally Clean Fuels And Petrochemicals, Ti̇mur Doğu, Di̇lek Varişli
Alcohols As Alternatives To Petroleum For Environmentally Clean Fuels And Petrochemicals, Ti̇mur Doğu, Di̇lek Varişli
Turkish Journal of Chemistry
In this review article, some of the challenging research areas related to the development of novel catalysts and catalytic processes for the chemical fixation of CO_2 by converting it to alcohols and ethers, and for the conversion of alcohols to olefins and other hydrocarbons are reviewed. Ethanol, methanol, and the ethers derived from them, such as DEE and DME, have good burning characteristics and may be considered attractive transportation fuel alternates. New processes for catalytic selective oxidation and dehydration of alcohols may open up new pathways for the production of olefins and other petrochemicals from non-petroleum feedstock. Developments in CO_2 …
Examination Of Some Commercial Sorptive Organobentonites, Müşerref Önal
Examination Of Some Commercial Sorptive Organobentonites, Müşerref Önal
Turkish Journal of Chemistry
For controlling organophilic partition nanophase (OPN) formation in some commercial sorptive organobentonites (OBs), 4 sample were selected randomly and examined by X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, differential thermal analysis (DTA), thermal gravimetric analysis (TGA), element analysis (EA), and nitrogen adsorption/desorption (N_2-AD) techniques. Since the d(001) values of the OB samples are between 1.94 and 3.36 nm, the pseudotrilayer or paraffin-type alkylammonium configuration located between the 2:1 layers of smectites is dominant. The bending and stretching type FTIR bands of the smectite surface and alkylammonium cations (AACs) are evidence of the formation of the OPN in the OBs. …
The Effect Of Ionic Electrolytes And Ph On The Zeta Potential Of Fine Coal Particles, Kemal Doymuş
The Effect Of Ionic Electrolytes And Ph On The Zeta Potential Of Fine Coal Particles, Kemal Doymuş
Turkish Journal of Chemistry
Many environmental problems are attributed to coal combustion and utilization, a subject receiving increasing attention worldwide. Some of these problems could be minimized or even avoided if coal cleaning, properly applied, was considered an economical and effective technique for removing hazardous elements or reducing their concentrations before combustion. The coal samples used in this study were separated into particle sizes of 4, 12, and 40 mesh. Then these samples were subjected to sink-float treatment in a ZnCl_2 solution of 1.3 density. The sample used for zeta potential determination was prepared by grinding both sink and float coal samples down to …
Synthesis Of New 5-Aryl Pyrido [3´, 2´: 4, 5] Thieno [2, 3-E] [1, 2, 3, 4] Tetrazolo [1, 5-C}] Pyrimidine Derivatives, Abolghasem Davoodnia, Mehdi Bakavoli, Mahsan Bashash, Mina Roshani, Rahele Zhiani
Synthesis Of New 5-Aryl Pyrido [3´, 2´: 4, 5] Thieno [2, 3-E] [1, 2, 3, 4] Tetrazolo [1, 5-C}] Pyrimidine Derivatives, Abolghasem Davoodnia, Mehdi Bakavoli, Mahsan Bashash, Mina Roshani, Rahele Zhiani
Turkish Journal of Chemistry
The synthesis of new 5-arylpyrido [3', 2': 4, 5] thieno [2, 3-e][1, 2, 3, 4] tetrazolo[1, 5-c] pyrimidine derivatives is described.
Catalytic Combustion Of Ethyl Acetate, Tuğba Gürmen Özçeli̇k, Süheyda Atalay, Erden Alpay
Catalytic Combustion Of Ethyl Acetate, Tuğba Gürmen Özçeli̇k, Süheyda Atalay, Erden Alpay
Turkish Journal of Chemistry
The catalytic combustion of ethyl acetate over prepared metal oxide catalysts was investigated. CeO, Co_2O_3, Mn_2O_3, Cr_2O_3, and CeO-Co_2O_3 catalysts were prepared on monolith supports and they were tested. Before conducting the catalyst experiments, we searched for the homogeneous gas phase combustion reaction of ethyl acetate. According to the homogeneous phase experimental results, 45% of ethyl acetate was converted at the maximum reactor temperature tested (350 °C). All the prepared catalysts were tested in order to find the best catalyst for the complete combustion of ethyl acetate. According to the results, all these catalysts produced higher conversion rates than that …