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Articles 1891 - 1920 of 2720
Full-Text Articles in Chemistry
New Diterpenoids From The Aerial Parts Of Salvia Pilifera, Ufuk Kolak
New Diterpenoids From The Aerial Parts Of Salvia Pilifera, Ufuk Kolak
Turkish Journal of Chemistry
Three new diterpenoids, piliferol (2\alpha, 20-dihydroxy-12-oxo- abieta-9(11),13-dien-8,20-ether) (1), salvipiliferol (2\alpha, 10\beta -dihydroxy-12-oxo-norabieta-9(11),13-dien) (2), and piliferalactone (2\alpha ,8-dihydroxy-12-oxo-abieta-9(11),13-dien-20-oic acid-8,20-lactone) (3), together with 7 known compounds, ursolic acid, oleanolic acid, betulinic acid, \alpha -amyrin, lupeol, \beta -sitosterol, and pectolinarigenin, have been isolated from the aerial parts of an endemic Salvia species, S. pilifera. Their structures were elucidated by spectral (UV, IR, 1D-, and 2D-NMR, and HRMS) methods.
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 …
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.
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 …
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.
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 …
Catalytic Processes For Clean Hydrogen Production From Hydrocarbons, Zeynep İlsen Önsan
Catalytic Processes For Clean Hydrogen Production From Hydrocarbons, Zeynep İlsen Önsan
Turkish Journal of Chemistry
Conversion of hydrocarbon fuels to hydrogen with a high degree of purity acceptable for fuel cell operation presents interesting challenges for the design of new selective catalysts and catalytic processes. Natural gas, LPG, gasoline, and diesel are regarded as promising hydrocarbon fuels. Methanol has received attention despite its toxicity, and ethanol has recently become of interest as a much less toxic and renewable resource. Selective catalytic processes considered for commercial use are based on steam reforming and partial oxidation of these fuels. Autothermal reforming (ATR) or indirect partial oxidation (IPOX) combines total oxidation (TOX), steam reforming (SR), and water-gas shift …
Synthesis And Isolation Of 1-Cyclohex-1,2-Dien-1-Ylbenzene From 1-(2-Iodocyclohex-1-En-1-Yl)Benzene And 1-(2-Iodocyclohex-2-En-1-Yl)Benzene, Mustafa Ceylan, Yakup Budak, M. Burcu Gürdere, İrfan Özdemi̇r, Esra Findik
Synthesis And Isolation Of 1-Cyclohex-1,2-Dien-1-Ylbenzene From 1-(2-Iodocyclohex-1-En-1-Yl)Benzene And 1-(2-Iodocyclohex-2-En-1-Yl)Benzene, Mustafa Ceylan, Yakup Budak, M. Burcu Gürdere, İrfan Özdemi̇r, Esra Findik
Turkish Journal of Chemistry
The key compounds, 1-(2-iodocyclohex-1-en-1-yl) benzene (12) and 1-(2-iodocyclohex-2-en-1-yl) benzene (13), for the generation of 1-cyclohex-1,2-dien-1-ylbezene (20) were synthesized starting with cyclohexanone. Separate reactions of 12 and 13 with KOtBu in benzene in a sealed tube at 180 °C gave 6 products: 1-cyclohex-1-en-1-ylbenzene (8), 2-phenylcyclohexanone (10), 1,8-diphenyl-2,3,4,4a,4b,5,6,7-octahydrobiphenylene (21), 8a-phenyl-1,2,3,4,6,7,8,8a-octahyd-rotriphenylene (22), 1,2-diphenylcyclohexene (23), and 1-(2-tert-butoxycyclohex-1-enyl) benzene (24). In addition, reactions of 12 and 13 under the same conditions in the presence of diphenylisobenzofuran and furan as trapping reagents afforded the [4 + 2] cyclo-adducts 30, 31, and 32 in good yields, respectively.
Synthesis And Characterization Of Oligo-2-[(2-Hydroxymethylphenylimino) Methyl] Phenol And Oligo-2-[(2-Hydroxymethylphenylimino) Methyl]-5-Bromo-Phenol, İsmet Kaya, Ayşe Erçağ, Süleyman Çulhaoğlu
Synthesis And Characterization Of Oligo-2-[(2-Hydroxymethylphenylimino) Methyl] Phenol And Oligo-2-[(2-Hydroxymethylphenylimino) Methyl]-5-Bromo-Phenol, İsmet Kaya, Ayşe Erçağ, Süleyman Çulhaoğlu
Turkish Journal of Chemistry
Oligo-2-[(2-hydroxymethylphenylimino) methyl] phenol O-(2-HMPIMP) and oligo-2-[(2-hydroxymet\-hylphenyl imino) methyl]-5-bromo-phenol O-(2-HMPIMBP) were synthesized by the oxidative polycondensation reaction using air as an oxidant in an aqueous alkaline medium at 70 °C. They were characterized by ^1H-NMR, FT-IR, UV-vis, TG, size exclusion chromatography (SEC) and elemental analysis. According to the SEC analyses, the number-average molecular weight (M_n), weight-average molecular weight (M_w) and polydispersity index (PDI) values of O-2-HMPIMBP and O-2-HMPIMP are 1100, 1600 g mol^{-1} and 1.45; and 6000, 6250 g mol^{-1} and 1.04, respectively. According to TG analyses, the weight losses of O-2-HMPIMP and O-2-HMPIMBP are 98.31% and 96.91%, respectively, at 900 …
Basic Al_2o_3 As A Recyclable Reagent For The Protection Of Carbonyl Groups With Phenylhydrazine Derivatives And Semicarbazides, Khodabakhsh Niknam, Ali Reza Kiasat, Bahador Karami, Nima Heydari
Basic Al_2o_3 As A Recyclable Reagent For The Protection Of Carbonyl Groups With Phenylhydrazine Derivatives And Semicarbazides, Khodabakhsh Niknam, Ali Reza Kiasat, Bahador Karami, Nima Heydari
Turkish Journal of Chemistry
Basic alumina is employed as an inorganic basic solid catalyst for the clean and less hazardous protection of carbonyl compounds, such as phenylhydrazones, 2,4-dinitrophenylhydrazones, semicarbazones, and thiosemicarbazones, under solvent-free conditions. The reactions proceed smoothly and require a short reaction time with good to excellent yields, and the alumina used can be recycled.
On-Line Preconcentration And Speciation Of Chromium By An 8-Hydroxyquinoline Microcolumn Immobilized On Surfactant-Coated Alumina And Flow Injection Atomic Absorption Spectrometry, Seyyed Hamid Ahmadi, Ali Mohammad Haji Shabani, Shayessteh Dadfarnia, Masoumeh Taei
On-Line Preconcentration And Speciation Of Chromium By An 8-Hydroxyquinoline Microcolumn Immobilized On Surfactant-Coated Alumina And Flow Injection Atomic Absorption Spectrometry, Seyyed Hamid Ahmadi, Ali Mohammad Haji Shabani, Shayessteh Dadfarnia, Masoumeh Taei
Turkish Journal of Chemistry
An on-line technique for the determination of chromium species with atomic absorption spectrometry is described. The method is based on separation and preconcentration of Cr(III) on a microcolumn of immobilized 8-hydroxyquinoline on surfactant-coated alumina. The adsorbed analyte is then eluted with 400 \mu L of 20% ethanolic solution of 1.5 mol L^{-1} hydrochloric acid and is transported to a flame atomic absorption spectrometer for quantification. The effects of pH, sample and eluent flow rate, sorption capacity, and the presence of various cations and anions on the sorption of Cr(III) were investigated. The sorption was quantitative in the pH 6-8 range, …
Voltammetric And Spectroscopic Studies Of Vanadium(V)-- Nicotinamide Interactions At Physiological Ph, Semi̇ha Çakir, Ender Bi̇çer
Voltammetric And Spectroscopic Studies Of Vanadium(V)-- Nicotinamide Interactions At Physiological Ph, Semi̇ha Çakir, Ender Bi̇çer
Turkish Journal of Chemistry
The interaction of nicotinamide (NA) with NH_4VO_3 at the physiological pH (pH 7.4) was studied by voltammetry and UV-Vis spectroscopy. The reduction of V(V) ions complexed with NA in phosphate buffer (pH 7.4) was observed as a well-defined reversible reduction peak at --0.35 V. The stoichiometric (metal:ligand) ratio of the complex of V(V) with NA was determined as 1:2 by the mole ratio method.
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.
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), …
Constituents Of Nepeta Crassifolia (Lamiaceae), Syed Amir Ibrahim, Muhammad Shaiq Ali
Constituents Of Nepeta Crassifolia (Lamiaceae), Syed Amir Ibrahim, Muhammad Shaiq Ali
Turkish Journal of Chemistry
A long chain ketone (crassifone), a pentacyclic triterpenoid coupled with fatty acid moiety (crassifoate), and an acyclic diterpenoid (crassifol) have been isolated from the ethanol soluble part of Nepeta crassifolia (Lamiaceae) collected from Kangavar, Iran. Structures of all the metabolites were elucidated with the aid of spectroscopic techniques, including 2D NMR experiments.
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.
Characterization And Co Oxidation Activity Studies Of Co-Based Catalysts, Fi̇li̇z Balikçi, Çi̇ğdem Güldür
Characterization And Co Oxidation Activity Studies Of Co-Based Catalysts, Fi̇li̇z Balikçi, Çi̇ğdem Güldür
Turkish Journal of Chemistry
Cobalt oxide based catalysts were developed for carbon monoxide oxidation at low temperature. The catalysts were prepared by co-precipitation and calcined at 200 °C. Several techniques were used to characterize the catalysts, such as X-ray diffractometer system, N_2 physisorption measurements, scanning electron microscope (SEM), and X-ray photoelectron spectroscopy. Carbon monoxide oxidation studies were carried out to investigate the relation between the characteristic properties of the catalysts and the catalytic activity. Catalytic activity measurements were studied from room temperature to 200 °C, using a feed composition of 1% CO, 21% O_2, and remaining He. X-ray studies showed that the catalysts have …
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 …
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 …
Synthesis Of Piperazine Based Polyimide In The Presence Of Ionic Liquids, Bülent Alici, Süleyman Köytepe, Turgay Seçki̇n
Synthesis Of Piperazine Based Polyimide In The Presence Of Ionic Liquids, Bülent Alici, Süleyman Köytepe, Turgay Seçki̇n
Turkish Journal of Chemistry
Ionic liquids derived from imidazolium, pyridinium, and alkylammonium salts were investigated not only as catalysts but also as solvents in polymerization of 1,4-bis(3-aminopropyl) piperazine. Results were compared with the conventional polymerizations in N-methylpyrrolidone (NMP). The catalyst has not only a detectable influence on polymer solubility, but also the degrees of polymerization are notably higher. They are even greater than the values obtained by conventional 2-stage polymerization in organic liquids. Ionic liquids based on imidazolium salts seem preferable over pyridinium and alkylammonium salts due to the higher degree of polydispersity of the polyimides obtained. The glass transition temperatures and thermal stabilities …
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.
A Convenient And Efficient Synthesis Of N-Acylsulfonamides In The Presence Of Silica Phosphoric Acid Under Heterogeneous And Solvent-Free Conditions, Ahmad Reza Massah, Mina Dabagh, Maryam Afshar, Ahmad Reza Momeni, Hamid Aliyan, Hamid Javaherian Naghash
A Convenient And Efficient Synthesis Of N-Acylsulfonamides In The Presence Of Silica Phosphoric Acid Under Heterogeneous And Solvent-Free Conditions, Ahmad Reza Massah, Mina Dabagh, Maryam Afshar, Ahmad Reza Momeni, Hamid Aliyan, Hamid Javaherian Naghash
Turkish Journal of Chemistry
Reaction of sulfonamides with carboxylic acid anhydrides and chlorides in the presence of silica phosphoric acid provided N-acyl sulfonamides in good to high yields. All reactions were performed under mild conditions in solvent-free and heterogeneous systems and the products were obtained in high purity after a simple work-up. Silica phosphoric acid could be reused for 3 times without visible loss of activity.
The Direct Electrochemical Synthesis Of Ti(Ii), Fe(Ii), Cd(Ii), Sn(Ii), And Pb(Ii) Complexes With N, N´-Bis(Salicylidene)-O-Phenylenediamine, Jianning Liu, Bing Zhang, Bowan Wu, Kejun Zhang, Shenli Hu
The Direct Electrochemical Synthesis Of Ti(Ii), Fe(Ii), Cd(Ii), Sn(Ii), And Pb(Ii) Complexes With N, N´-Bis(Salicylidene)-O-Phenylenediamine, Jianning Liu, Bing Zhang, Bowan Wu, Kejun Zhang, Shenli Hu
Turkish Journal of Chemistry
The electrochemical oxidation of anodic Ti, Fe, Cd, Sn, and Pb (=M) into acetonitrile solutions of N,N'-bis(salicylidene)-o-phenylenediamine [SalophH_2] gives the corresponding M(Saloph) complexes in high yield. The mechanism of the electrochemical reactions is discussed. SalophH_2 forms complexes (1:1 molar ratio) with titanium, iron, cadmium, tin, and lead ions. The complexes have been characterized by elemental analyses, molar conductivity measurements, and infrared and electronic spectral data. The SalophH_2 complexes of iron(II) and cadmium(II) have been further identified by ^1H-NMR and mass spectra.
Synthesis And Characterization Of Nife_2o_4 Nano-Octahedrons By Edta-Assisted Hydrothermal Method, Nermi̇n Kasapoğlu, Abdulhadi̇ Baykal, Muhammet S. Toprak, Yüksel Köseoğlu, Harun Bayrakdar
Synthesis And Characterization Of Nife_2o_4 Nano-Octahedrons By Edta-Assisted Hydrothermal Method, Nermi̇n Kasapoğlu, Abdulhadi̇ Baykal, Muhammet S. Toprak, Yüksel Köseoğlu, Harun Bayrakdar
Turkish Journal of Chemistry
Octahedral-like NiFe_2O_4 ferrite nanocrystals were synthesized using EDTA-assisted hydrothermal method under mild conditions. XRD and FTIR analysis were used for composition and structure investigation. XRD analysis revealed a pure ferrite phase with high crystallinity. Morphological investigation by SEM showed octahedral nanocrystals with an average particle size of \sim 40 nm. Crystallite size calculated from XRD peak broadening resulted in an average crystallite size of 39 nm, matching well with the SEM observations. TEM analysis and corresponding electron diffraction confirmed the octahedral morphology and single crystallinity of octahedral nanoparticles. Magnetic measurements showed that NiFe_2O_4 octahedrons have smaller coercivity than bulk ferrite …