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2007

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Articles 511 - 540 of 658

Full-Text Articles in Chemistry

Preparation, Spectroscopy, Antimicrobial Assay, And X-Ray Structure Of Dimethyl Bis-(4-Methylpiperidine Dithiocarbamato-S,S`)-Tin(Iv), Zia-Ur Rehman, Saira Shahzadi, Saqib Ali, Guo-Xin Jin Jan 2007

Preparation, Spectroscopy, Antimicrobial Assay, And X-Ray Structure Of Dimethyl Bis-(4-Methylpiperidine Dithiocarbamato-S,S`)-Tin(Iv), Zia-Ur Rehman, Saira Shahzadi, Saqib Ali, Guo-Xin Jin

Turkish Journal of Chemistry

Dimethyl bis(4-methylpiperidine dithiocarbamato-S,S')-tin(IV) was synthesized and characterized by elemental analysis, IR and mass spectrometry, multinuclear NMR (^1H- and ^{13}C-NMR), and X-ray single crystal analysis. IR data showed that the ligand acts as a bidentate in the solid state. X-ray data showed the unsymmetrical nature of the ligand towards coordination to tin. It crystallized in the monoclinic P2_1/n space group. Its geometry is distorted octahedral. Antimicrobial activity data shows that the complex exhibits significantly more activity than the free ligand.

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A New Alkaloid From Isatis Costata, Itrat Fatima, Itrat Anis, Ijaz Ahmad, Abdul Malik, Nighat Afza Jan 2007

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.

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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 Jan 2007

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 …

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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 Jan 2007

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 …

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The Synthesis Of 2-(Chloromethyl)-6-Hydroxy-2h-Pyran-3 (6h)-One Via Achmatowicz Rearrangement, Zuhal Gerçek Jan 2007

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%).

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Activation Of Light Alkanes On Pure And Fe And Al Doped Silica Clusters: A Density Functional And Oniom Study, Mehmet Ferdi̇ Fellah, Işik Önal Jan 2007

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 …

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Drift Tube Ion Mobility Measurements For Thermochemistry, Kinetics And Polymerization Of Cluster Ions, Ridha Ben Mohsen Mabrouki Jan 2007

Drift Tube Ion Mobility Measurements For Thermochemistry, Kinetics And Polymerization Of Cluster Ions, Ridha Ben Mohsen Mabrouki

Theses and Dissertations

In this work, the Drift Tube Ion Mobility technique is used to study the hydrophobic hydration and solvation of organic ions and measure the thermochemistry and kinetics of ion-molecule reactions. Furthermore, an exploratory study of the intracluster polymerization of isoprene will be presented and discussed. The ion hydration study is focused on the C3H3+ cation1 and Pyridine▪+ radical cation.2 The chemistry of the cyclic C3H3+ cation1 has received considerable attention and continues to be an active area of research.3-7 The binding energies of the first 5 H2O molecules to c-C3H3+ were determined by equilibrium measurements. The measured binding energies of …

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The Spectral And Photophysical Characterization Of Water Solubilizing Metal Phthalocyanines For Highly Sensitive Detection In Biological Studies, Vera Tamisha Verdree Jan 2007

The Spectral And Photophysical Characterization Of Water Solubilizing Metal Phthalocyanines For Highly Sensitive Detection In Biological Studies, Vera Tamisha Verdree

LSU Doctoral Dissertations

Efforts to improve the technology for DNA analyses stimulated the work presented here to develop a series of fluorescent probes that would aid in the increased multiplexing capabilities allowing the ability to detect multiple targets in a single measurement. Typically, spectral discrimination has been used to identify each DNA fragment in sequencing or diagnostic applications by means of unique emission properties from several labeling dyes. This has been accomplished with labels that fluoresce in the visible region. The limitations with these dyes is the broad emission profile making discrimination difficult, high intrinsic biological fluorescence and structural differences of the dyes …

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Catalytic Combustion Of Ethyl Acetate, Tuğba Gürmen Özçeli̇k, Süheyda Atalay, Erden Alpay Jan 2007

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 …

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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 Jan 2007

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.

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Fused Heterocycles: Synthesis Of Some New Imidazopyridines As Anti-Mycobacterial Agents, Bi̇rgül Özden Kasimoğullari, Zafer Cesur Jan 2007

Fused Heterocycles: Synthesis Of Some New Imidazopyridines As Anti-Mycobacterial Agents, Bi̇rgül Özden Kasimoğullari, Zafer Cesur

Turkish Journal of Chemistry

The reaction of semicarbazones bearing an imidazo[1,2-a]pyridine ring system with mercaptoacetic acid was investigated. The anti-mycobacterial activity of the compounds thus obtained were evaluated against Mycobacterium tuberculosis H_{37}Rv, using rifampin as the standard. Only IVe showed activity at 6.25 \mu g mL^{-1}.

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A New And Convenient Method Of Generating Alkyl Isocyanates From Alcohols, Thiols, And Trimethylsilyl Ethers Using A 2,4,6-Trichloro[1,3,5] Triazine/N-Bu_4nocn, Batool Akhlaghinia, Sima Samiei Jan 2007

A New And Convenient Method Of Generating Alkyl Isocyanates From Alcohols, Thiols, And Trimethylsilyl Ethers Using A 2,4,6-Trichloro[1,3,5] Triazine/N-Bu_4nocn, Batool Akhlaghinia, Sima Samiei

Turkish Journal of Chemistry

Alkyl isocyanates are prepared in good to excellent yields by treatment of alcohols, thiols, and trimethylsilyl ethers with 2,4,6-trichloro[1,3,5] triazine/n-Bu_4NOCN in acetonitrile. This method is highly selective for conversion of 1° alcohols to alkyl isocyanates in the presence of 2° and 3° alcohols, thiols, and trimethylsilyl ethers.

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Efficient Method For Tetrahydropyranylation Of Phenols And Alcohols Using 2,4,6-Trichloro[1,3,5]Triazine, Batool Akhlaghinia, Elham Roohi Jan 2007

Efficient Method For Tetrahydropyranylation Of Phenols And Alcohols Using 2,4,6-Trichloro[1,3,5]Triazine, Batool Akhlaghinia, Elham Roohi

Turkish Journal of Chemistry

Alcohols and phenols were tetrahydropyranylated in the presence of 2,4,6-trichloro[1,3,5]triazine in good to excellent yields in acetonitrile.

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Gold(Iii) Complex Of Caffeine: Synthesis, Isolation And Spectroscopic Characterization, Bojidarka Ivanova Jan 2007

Gold(Iii) Complex Of Caffeine: Synthesis, Isolation And Spectroscopic Characterization, Bojidarka Ivanova

Turkish Journal of Chemistry

Au(III)-caffeine complex was synthesized and characterized by means of solid-state linear-dichroic infrared spectral analysis (IRLD), ^1H-NMR, MS, DSC and TGA methods. The caffeine (I) is monodentate and coordinated with metal ion through its N9 atom at molar ratio metal to ligand 1:1. The other 3 positions in the Au(III) coordination sphere are occupied by Cl^-, thus forming [Au^{3+}(C_8H_{10}N_4O_2)Cl_3] complex. IR-characteristic band assignment in the 4000-400 cm^{-1} IR region of pure ligand and corresponding Au(III)complex was performed.

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Template-Free Synthesis Of Zsm-5 Type Zeolite Layers On Porous Alumina Disks, Hali̇l Kalipçilar, Ali̇ Çulfaz Jan 2007

Template-Free Synthesis Of Zsm-5 Type Zeolite Layers On Porous Alumina Disks, Hali̇l Kalipçilar, Ali̇ Çulfaz

Turkish Journal of Chemistry

ZSM-5 crystals were synthesized from template-free batches on macroporous \alpha-alumina disks. The SiO_2/Al_2O_3 ratio of the synthesis gel influenced the crystal morphology, surface coverage and intergrowth among the crystals. Prismatic ZSM-5 crystals covered the disk surface when the SiO_2/Al_2O_3 ratio of the batch was higher than 100, whereas spherical polycrystalline particles of ZSM-5 were obtained from batches with a SiO_2/Al_2O_3 ratio of 80. Mordenite type zeolite was formed on the disk surface due to the incorporation of alumina dissolved from the disk when the time of crystallization was extended. The effects of silica source and seeding of the support surface …

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Preparation And Properties Of Triethoxyvinylsilane-Modified Styrene - Butyl Acrylate Emulsion Copolymers, Hamit Javaherian Naghash, Akram Karimzadeh, Ahmad Reza Momeni, Ahmad Reza Massah, Hamid Alian Jan 2007

Preparation And Properties Of Triethoxyvinylsilane-Modified Styrene - Butyl Acrylate Emulsion Copolymers, Hamit Javaherian Naghash, Akram Karimzadeh, Ahmad Reza Momeni, Ahmad Reza Massah, Hamid Alian

Turkish Journal of Chemistry

The copolymers of triethoxyvinylsilane (TEVS) with styrene (St), butyl acrylate (BA), and methacrylic acid (MAA) were prepared by emulsion polymerization. The copolymerization was carried out by using auxiliary agents at 90 °C in the presence of potassium peroxodisulfate (KPS) as the initiator. Nonylphenol ethylene oxide -- 40 units (NP-40) and sodium lauryl sulfoacetate (SLSA) were used as nonionic and anionic emulsifiers, respectively. The resulting copolymers were characterized by Fourier transform infrared spectroscopy (FTIR). Thermal properties of the copolymers were studied by thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC). The morphology of copolymers was also investigated by optical microscopy (OM) …

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Studies On The Anion Recognition Properties Of Synthesized Receptors Iii: A Novel Thiourea-Based Receptor Constructed By Benzo-15-Crown-5 For Sensing Anions In A Strong Polar Solvent, You-Ming Zhang, Hai-Xian Ren, Yan-Qing Zhou, Rong Luo, Wei-Xia Xu, Tai-Bao Wei Jan 2007

Studies On The Anion Recognition Properties Of Synthesized Receptors Iii: A Novel Thiourea-Based Receptor Constructed By Benzo-15-Crown-5 For Sensing Anions In A Strong Polar Solvent, You-Ming Zhang, Hai-Xian Ren, Yan-Qing Zhou, Rong Luo, Wei-Xia Xu, Tai-Bao Wei

Turkish Journal of Chemistry

A new series of receptors were designed and synthesized, and their interactions with anions, such as F^-, Cl^-, Br^-, I^-, CH_3COO^-, HSO_4^-, and NO_3^-, in DMSO solvent were investigated using UV-Vis absorption spectroscopy. The results showed that hydrogen-bonding complexes were formed between the receptors and the tested anions, such as CH_3COO^- and F^-. It was also found that the selectivity of the receptors for anions could be efficiently tuned by changing the place of the substituent group at the N-phenyl moiety. The recognition mechanism and binding mode are discussed. These findings were expected to be of significance for designing and …

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New Diterpenoids From The Aerial Parts Of Salvia Pilifera, Ufuk Kolak Jan 2007

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.

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Benzimidazolylidene Carbene Ligated Palladium Catalysis Of The Heck Reaction In Aqueous Media, İsmai̇l Özdemi̇r, Yetki̇n Gök, Nevi̇n Gürbüz, Beki̇r Çeti̇nkaya Jan 2007

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.

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Fragmentation Of Xe^{129} In The Liquid-Gas Phase Transition Region, Mehmet Erdoğan, Ni̇hal Büyükçi̇zmeci̇, Riza Oğul Jan 2007

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 …

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A Novel Degradable Adsorbent Of The Hyperbranched Aliphatic Polyester Grafted Cellulose For Heavy Metal Ions, Peng Liu Jan 2007

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), …

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A New Ursane-Type Triterpenoid From Salvia Santolinifolia, Zaher Ahmad, Sajid Mehmood, Rehana Ifzal, Abdul Malik, Nighat Afza, Mohammad Ashraf, Erum Jahan Jan 2007

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.

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A Mechanistic Approach To Elucidate Ethanol Electro-Oxidation, Ni̇yazi̇ Alper Tapan Jan 2007

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, …

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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 Jan 2007

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 …

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Deactivation Of A Co-Precipitated Co/Al_2o_3 Catalyst, Meltem Yildiz, Ayşe Ni̇lgün Akin Jan 2007

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 …

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Alcohols As Alternatives To Petroleum For Environmentally Clean Fuels And Petrochemicals, Ti̇mur Doğu, Di̇lek Varişli Jan 2007

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 …

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Hyphenated Hplc-Ms Technique For Analysis Of Compositional Monosaccharides Of Transgenic Corn Glycoprotein And Characterization Of Degradation Products Of Diazinon, Fonofos And Aldicarb In Various Oxidation Systems, Tongwen Wang Jan 2007

Hyphenated Hplc-Ms Technique For Analysis Of Compositional Monosaccharides Of Transgenic Corn Glycoprotein And Characterization Of Degradation Products Of Diazinon, Fonofos And Aldicarb In Various Oxidation Systems, Tongwen Wang

Doctoral Dissertations

"The studies of this dissertation are composed of two sections. The first one deals with the analysis of compositional monosaccharides of transgenic corn glycoproteins. The method used in this study involved derivatization of monosaccharides with two fluorophores followed by HPLC/fluorescence detection for quantitative studies, and by HPLC/SSI/MS for identification confirmation of individual monosaccharide...The second section investigates the degradation processes of several pesticides including diazinon, fonofos and aldicarb in various oxidation systems"--Abstract, page iv.

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Physical Analysis Of Human Hair, Lea Marie Dankers Jan 2007

Physical Analysis Of Human Hair, Lea Marie Dankers

Masters Theses

"Physical analysis of human hair has been performed to determine the effects of chemical treatments on hair samples. Five samples including an untreated sample were analyzed using various methods. The methods included differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), Fourier transform infrared spectroscopy (FTIR), and carbon-13 cross polarization/magic-angle spinning nuclear magnetic resonance (¹³C CP/MAS NMR)"--Abstract, page iii.

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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 Jan 2007

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.

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Kinetics Of Synthesis Of Isobutyl Propionate Over Amberlyst-15, Ali̇me İzci̇, Hali̇t Levent Hoşgün Jan 2007

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 …

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