Physical Sciences and Mathematics Commons^™

Reaction Of Tribromonitromethane With Aldehydes And Ketones In The Presence Of Zn Metal In Aqueous Medium, Ali̇ Shaker Mahasneh

Turkish Journal of Chemistry

Aldehydes and ketones react with tribromonitromethane in the presence of zinc metal dust, ammonium chloride and water to give dibromonitroalcohols in good yields.

Studies On The Synthesis Of Some Substituted Flavonyl Thiazolidinedione Derivatives-I, Oya Bozdağ, Gülgün Ayhan Kilcigi̇l, Meral Tunçbi̇lek, Rahmi̇ye Ertan

Turkish Journal of Chemistry

Synthesis and some physico-chemical properties of five flavonyl thiazolidinedione derivatives are described. These products were synthesized by Knoevenagel condensation from flavone-6-carboxaldehyde and 3-substituted 2,4-thiazolidinediones.

Complexation Of Benzoate Ligand With The Divalent D^10 Acceptors At Different Temperatures, Betül Başaran, Efrai̇m Avşar

Turkish Journal of Chemistry

The complex formation between zinc(II), cadmium(II), mercury(II) and benzoate ions was studied potentiometrically with glass electrode at different temperatures. The measurements have been performed in a perchlorate medium of the unit ionic strength at 25, 30, 35 and 40°C. The stability constants of the complexes were found in the order of increasing softness i.e. Zn(II) < -Cd(II)

Supercritical Co_2 Extraction Of Ethanol, A. Güvenç, Ü. Mehmetoğlu, A. Çalimli

Turkish Journal of Chemistry

Extraction of ethanol was studied from both synthetic ethanol solution and fermentation broth using supercritical CO_2 in an extraction apparatus in ranges of 313 to 333 K and 80 to 160 atmospheres, for varying extraction times. The experimental system consists mainly of four parts: a CO_2 storage system, a high-pressure liquid pump, an extractor and a product collection unit. Samples were analyzed by gas chromatography. Effects of temperature, pressure, extraction time, initial ethanol concentration and consecutive solvent feeding on extraction yield were investigated. It was found that increasing the initial ethanol concentration and extraction pressure and decreasing the extraction temperature …

The Characterization Of Na_2 Co_3 Activated Kütahya Bentonite, Nuray Yildiz, Yüksel Sarikaya, Ayla Çalimli

Turkish Journal of Chemistry

A calcium bentonite from Kütahya region (Turkey) was activated with Na_2CO_3 at various ratios (1, 2, 2.5, 5, 10, 15g / 100 g bentonite). Due to ion exchange, the original Ca-bentonite was converted to Na-bentonite by Na_2CO_3 when the Na_2CO_3/bentonite ratio was 2.5\% (2.5 g Na_2CO_3/100 22g bentonite, A2.5). Na-bentonite (A2.5) obtained by soda activation was treated with 3 g CaCl_2/ 100 g bentonite and converted to Ca-bentonite again. The products were investigated by chemical analysis, X-ray diffraction and micropore analysis. It was observed that the cation exchange capacity (CEC) did not change until the soda ratio was 2.5\%. After …

Mass Spectral Studies Of Some Triorganotin Derivatives Containing Carboxylates, Moazzam Hussain Bhatti, Sagib Ali, Muhammad Mazhar, Muhammad Danish, Muhammad Azi̇z Chaudhary

Turkish Journal of Chemistry

The mass spectra of 16 triorganotin compounds having the general formula R_3SnL where R= CH_3, C_4H_9, C_6H_5, C_6H_{11} and L=trans-3-(2-furanyl)-2-propenoate, trans-m-methyl cinnamate, 2-(2,3-dimethylphenyl)aminobenzoate and trans-3-(2-thienyl)-2- propenoate, were investigated. The possible fragmentation pattern is discussed in detail.

Effect Of Temperature On The Electrooxidation Of Some Organic Molecules On Pt Doped Conducting Polymer Coated Electrodes, İpek Beceri̇k, Fehmi̇ Fiçicioğlu, Fi̇gen Kadirgan

Turkish Journal of Chemistry

Polymer modified electrodes are of importance as possible electrocatalysts for various electrode reactions, i.e., platinum incorporated into polypyrrole or polyaniline films are known to be good systems for the electrooxidation of various organic molecules. In this study, the effect of temperature on the electrooxidation of D. glucose and methanol on Pt doped films was investigated, apparent activation energies were calculated and the results were evaluated.

Electrochemical Reduction Of Methyl Cinnamate In The Presence Of 1,3-Bis(4-Methyl Phenylsulphonyloxy)Propane, Mustafa Güllü

Turkish Journal of Chemistry

Electrochemical reduction of methyl cinnamate in the presence of a dielectrophile, such as 1,3-bis(4-methyl phenylsulphonyloxy)propane gives two major products: trans- (\pm) methyl 2-phenylcyclopentanecarboxylate and trans- (\pm) methyl 2,3-diphenyl-5-oxo-cyclopentanecarboxylate. The ratio of products basically depends on the electrolysis conditions.

Autocatalytic Reduction Of Dichloro 5, 10, 15, 20 Tetraphenylporphinatoplatinum(Iv) By 1-Methylimidazole, F. Ece Bulak

Turkish Journal of Chemistry

It was observed that in toluene solution, excess 1-methyl-imidazole (Melm) reduces dichloro 5, 10, 15, 20 tetraphenyl-porphinatoplatinum(IV) (PtTPPCl_2) to tetraphenylporphinato-platinum(II) (PtTPP) autocatalytically (Fig. 1). There was no Pt(III) intermediate or 1-methylimidazole radical detected by Electron Resonance Spectroscopy (ESR) at 25°C. The reaction was found to be autocatalyzed by the PtTPP product when the 1-methylimidazole to PtTPPCl_2 concentration ratio is about 10^4 or more. From the data obtained it is reasonable to suppose that aggregation of the PtTPP product with PtTPPCl_2 plays an important role in this reduction process.

X-Ray Crystal Structures And The Facile Oxidative (Au−C) Cleavage Of The Dimethylaurate(I) And Tetramethylaurate(Iii) Homologues, Dunming Zhu, Sergey V. Lindeman, Jay K. Kochi

Chemistry Faculty Research and Publications

Dimethylaurate(I) has been prepared as the crystalline tetrabutylammonium salt for comparison with the known tetramethylaurate(III) analogue. The linear structure of dimethylaurate(I) and the square-planar structure of tetramethylaurate(III) have both been confirmed by X-ray crystallography. One-electron oxidation of dimethylaurate(I) by either ferrocenium or arenediazonium cations produces the metastable dimethylgold(II) intermediate, which can be trapped as the paramagnetic 9,10-phenanthrenequinone (PQ) adduct. Otherwise, dimethylgold(II) is subject to rapid reductive elimination of ethane and affords metallic gold (mirror). The analogous oxidation of tetramethylaurate(III) by ferrocenium, arenediazonium, or nitrosonium cations also proceeds via electron transfer to generate the putative tetramethylgold(IV) intermediate. The highly unstable (CH …

Reply To Comment On ‘Nondipole Resonant X-Ray-Raman Spectroscopy: Polarized Inelastic Scattering At The K Edge Of Cl2,’, J. D. Mills, J. A. Sheehy, T. A. Ferrett, S. H. Southworth, R. Mayer, Dennis W. Lindle, P. W. Langhoff

Chemistry and Biochemistry Faculty Research

Mills et al. Reply: In their Comment on our Letter [1], Gel’mukhanov and Ågren [2] reiterate recent assertions [3] based on their earlier theoretical studies [4]. The primary purpose of their Comment is apparently to refute our stated conclusion that core-excited-state localization/ delocalization mechanisms are irrelevant to interpretations of reported Raman scattering experiments on homonuclear diatomic molecules.

Monitoring The Effects Of Indoor Pollution Using Fourier Transform Infrared Spectroscopy, Rachel Farrell

Presidential Scholars Theses (1990 – 2006)

Fourier Transform Infrared Spectroscopy {FTIR) was used to develop an effective way to monitor indoor pollution and to observe the effects of such indoor pollution under various conditions of the ventilation system of McCollum Science Hall of the University of Northern Iowa, Cedar Falls, Iowa. This was done by monitoring the absorbance of acetone as it evaporated over time, and the data were used to create concentration vs. time plots. Several parameters from these plots were used to judge the ventilation system, with some general conclusions including that having the system on reduces peak time and end time. Also, the …

Additives For Increased Atomic Oxygen Resistance In Cyanate Ester Resins, Sandeep Amar Saggar

Dissertations, Theses, and Masters Projects

No abstract provided.

Analysis Of Mercury Coordination Environments Of Tridentate And Tetradentate Imidazole Based Ligands By X-Ray Crystallography And Nmr Spectroscopy, Geoffrey Murphy

Dissertations, Theses, and Masters Projects

No abstract provided.

Semiclassical Calculation Of Cumulative Reaction Probabilities, David J. Tannor, Sophya V. Garashchuk

Faculty Publications

Calculation of chemical reaction rates lies at the very core of theoretical chemistry. The essential dynamical quantity which determines the reaction rate is the energy-dependent cumulative reaction probability, N(E), whose Boltzmann average gives the thermal rate constant, k(T). Converged quantum mechanical calculations of N(E) remain a challenge even for three- and four-atom systems, and a longstanding goal of theoreticians has been to calculate N(E) accurately and efficiently using semiclassical methods. In this article we present a variety of methods for achieving this goal, by combining semiclassical initial value …

Semiclassical Calculation Of Cumulative Reaction Probabilities, Sophya V. Garashchuk, D. J. Tannor

Faculty Publications

Calculation of chemical reaction rates lies at the very core of theoretical chemistry. The essential dynamical quantity which determines the reaction rate is the energy-dependent cumulative reaction probability, N(E), whose Boltzmann average gives the thermal rate constant, k(T). Converged quantum mechanical calculations of N(E) remain a challenge even for three- and four-atom systems, and a longstanding goal of theoreticians has been to calculate N(E) accurately and efficiently using semiclassical methods. In this article we present a variety of methods for achieving this goal, by combining semiclassical initial value …

Investigations Of A Phenanthroline-Based Azo Dye Ligand And Of Re(I) And Ru(Ii) Complexes Based On This Ligand, Yan Zhang

Masters Theses

A 1,10-phenanthroline based azo dye ligand, phen-azo-phenol, produced by diazotizing 5-amino-1,10-phenanthroline (5-NH₂-phen) and then coupling to phenol, and several transition metal complexes containing this ligand, have been synthesized and characterized. The phen-azo-phenol ligands attach to Re(I) and Ru(II) through the phenanthroline linkage to form stable polypyridyl complexes. These complexes show greatly enhanced absorption properties in the visible region when compared to the well-known analogous bipyridine and phenanthroline containing complexes. The visible light absorption of the free ligand and the complexes containing this ligand are greatly affected by the position of the deprotonation equilibrium of the -OH group on …

Investigating The Allosteric Behavior Of Malate Dehydrogenase From Escherichia Coli, Eman M. Ghanem

Masters Theses

Regulatory mechanisms of malate dehydrogenase from E.coli (eMDH) involving NADH as an allosteric effector were investigated. The reaction was studied in both directions: malate oxidation and oxaloacetate reduction. When malate was the variable substrate, a plot of rate against substrate concentration was sigmoidal in the presence of 0.065 mM NADH, which indicates the presence of an allosteric site for NADH on the enzyme. Binding of NADH at the allosteric site causes conformational changes in the active site and, thereby, changes the catalytic activity of the enzyme. An increase in K_m value, from 1.3 to 3.9 mM malate was observed, …

Optimization Of The Reaction Of Hexamethyldisilazane On A Fumed Silica Surface, Frederick R. Jones

Masters Theses

Hexamethyldisilazane (HMDS) is commonly used to transfer trimethylsilyl (TMS) groups to silica surfaces. While studies have been done examining individual factors that influence the reaction, no investigations have reported how these factors affect each other. The factors examined in this study include temperature, presence of catalyst (butylamine), pretreatment, time, concentration, solvent, and presence of water in the solvent. The purpose of this study is to examine potential factors and two-way interactions to determine which significantly affect the yield and produce an optimum set of conditions.

The HMDS reactions occurred in an organic solvent slurry under nitrogen. Using statistical experimental design, …

The Hofmann Rearrangement Using Household Bleach: Synthesis Of 3-Nitroaniline, Ram S. Mohan, Keith A. Monk

Ram S. Mohan

No abstract provided.

Oxidation Of Benzoins To Benzils Using Bismuth(Iii) Nitrate-Copper(Ii) Acetate, Ram S. Mohan, Steven A. Tymonko, Bryce A. Nattier

Ram S. Mohan

Contraction Of The Model For The Bray-Liebhafsky Oscillatory Reaction By Eliminating Intermediate I2o, Zeljko D. Cupic

Zeljko D Cupic

No abstract provided.

Effect Of Temperature On Retention Of Enantiomers Of Β-Methyl Amino Acids On A Teicoplanin Chiral Stationary Phase, Antal Péter, Gabriella Török, Daniel W. Armstrong, Géza Tóth, Dirk Tourwé

Chemistry Faculty Research & Creative Works

The isocratic retention of enantiomers of β-methyl amino acids (β-methyltyrosine, β-methylphenylalanine, β-methyltryptophan and β-methyl-1,2,3,4-tetrahydroisoquinoline-3-carboxylic acid) was studied on a teicoplanin-containing chiral stationary phase at different temperatures and at different mobile phase compositions, using the reversed-phase mode. With variation of both mobile phase composition and temperature, almost baseline separations could be achieved for all four enantiomers of sterically hindered amino acids. The retention factors and selectivity factors for the enantiomers of all investigated compounds decreased with increasing temperature. The natural logarithms of the retention factors (ln k) of the investigated compounds depended linearly on the inverse of temperature (1/T). van 't …

22. Yu Tongyin, Otto Vogl, Shukuan Fu

Otto Vogl

No abstract provided.

International Symposium On Ionic Polymerization Ip'97, Otto Vogl, Przemyslaw Kubisa

Otto Vogl

No abstract provided.

Phorbol 12-Myristate 13-Acetate Stimulates Lysophosphatidic Acid Secretion From Ovarian And Cervical Cancer Cells But Not From Breast Or Leukemia Cells, Zhongzhou Shen, Jerome Belinson, Richard E. Morton, Yan Xu

Chemistry Faculty Publications

Lysophosphatidic acid (LPA) is present in ascites from patients with ovarian cancer. It stimulates calcium release and growth of ovarian cancer cells bothin vitroandin vivo.Recently, we found that LPA levels were significantly elevated in plasma from patients with ovarian cancer and other gynecological cancers. In contrast, LPA levels were not elevated in patients with breast cancer and leukemias. In view of this, we investigated whether gynecological cancer cells could produce LPA. LPA was extracted from the supernatant of cells culturedin vitroand purified by thin layer chromatography. After hydrolysis and transmethylation, the fatty acid derivatives were analyzed by gas chromatography. We …

Investigation Of Peptide-Dna Interactions: Synthesis, Characterization And Applications Of Lysyl-Fluorophenylalaninamides, Teresita T. Ortega

Seton Hall University Dissertations and Theses (ETDs)

.

Synthesis, Characterization And Photophysical Behavior Of A Cr(Iii) Bimetallic System, Yan Chen

Masters Theses

Many binuclear transition metal complexes have been studied to understand the nature of interactions between the metal centers. People have found Simultaneous Pair Excitation phenomenon in some bimetallic system that can serve as a potential source of Non-Linear Optical behavior.

Thus a series of Cr₂ -([14]aneN₄)₂-X₄ⁿ⁺ complexes were synthesized and characterized. Only the cis,cis configuration was found. The results were compared with those of their monomer analogs. The electronic structures are very similar in both monomer and dimer complexes. The quantum yield, UV-Vis absorption and lifetime studies suggested a possible coupling between the …

Separation And Determination Of Monochlorophenols By Capillary Zones Electrophoresis, Zarina Yasmin Banu

Masters Theses

Chlorine has been widely used in industry. One of the most common uses of chlorine is in municipal water treatment plants. Chlorine reacts with a variety of organic compounds, among these are phenol and its derivatives which are commonly found in natural waters. When these compounds react with chlorine, a variety of chlorine substituted and oxidized products result depending on concentrations, pH, and temperature. In order to study these reactions it is necessary to separate and determine the various products produced.

Earlier studies have shown 3-chloro and 4-chlorophenol cannot be separated by commercial GLC columns. GC/MS (electron impact) measurements cannot …

Development Of Chronoamperometric Logarithmic Signatures With Application To Drug-Package Interactions And Mechanism Elucidation, Beth Sarsfield

Seton Hall University Dissertations and Theses (ETDs)

.