Chemistry Commons^™

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

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

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 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 …

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.

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 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 …

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 …

Synthesis And Characterization Of Polyimides Prepared From Optically Active (R,R) And (S,S)-1,3-Bis(P-N,N´-Dimethylaminobenzyl)-Perhydrobenzimidazol-2-Thion, Murat Yi̇ği̇t, Turgay Seçki̇n, Süleyman Köytepe, Engi̇n Çeti̇nkaya

Turkish Journal of Chemistry

This paper presents the synthesis and characterization of polyimides containing a chiral (R,R) or (S,S) 1,3-bis(p-N,N´-dimethylaminobenzyl)-perhydrobenzimidazol-2-thion unit in the backbone. The reactions occur between equimolar amounts of a dianhydride and an aromatic dimethylamine in the presence of the solvent N-methyl-2-pyrollidone (NMP). In this work, the chiral monomer RR and SS -1,3-bis(p-N,N´-dimethylaminobenzyl)-perhydrobenzimidazol- 2-thion were used as diamines. The polyimides obtained were characterized by thermogravimetry (TGA), differential thermal analysis (DTA), differential scanning calorimeter (DSC), infrared spectroscopy (FT-IR), and gel permeation chromatography (GPC). It was found that the composition of the polymer had a significant effect upon the thermal behavior of the material.

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

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

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.

A New Approach To Furan-Containing Macrolactones, Christoph Schmidt, Ruth Messmer, Franz Bracher, Jurgen Krauss

Turkish Journal of Chemistry

Furan and tetrahydrofuran heterocycles are part of many natural products, like the Galerucella pheromone, furano epothilones, bipinnatin, and amphidinolides. This paper describes a short and efficient synthetic approach to furan-containing macrolactones in 4 steps, including as key steps a Sonogashira reaction and an olefin metathesis. The resulting compounds were tested at the National Cancer Institute for their cytotoxicity, but did not exhibit significant cytotoxicity in the human tumour cell line screen.

Polymorphism Of Four Enantiotropic Crystalline Systems Containing Ni(Ii), H2O, 15-Crown-5 And No3-, Maxime Andre Siegler

University of Kentucky Doctoral Dissertations

The series of compounds [M(H₂O)₂(15-crown-5)](NO₃)₂, M = Mg, Mn, Co, Cu and Zn, has been extended to include two new phases for M = Fe and two new phases for M = Ni. The system [M(H₂O)₂(15-crown-5)](NO₃)₂ is remarkable for having many high-Z’ phases (Z’ > 1) with similar packing and for having solid-solid phase transitions through which there is no significant loss of crystallinity. The synthesis of the analogous Ni complex was carried out. Single-crystal X-ray diffraction showed …

Evaluation Of Fluorapatite As A Waste-Form Material, Dennis W. Lindle, Oliver Hemmers, Dale L. Perry

Separations Campaign (TRP)

Argonne National Laboratory has proposed a new extraction procedure to handle TRISO-coated fuels, the Fluoride Extraction Process, or FLEX. The FLEX process is designed to separate the uranium in the fuel from the actinides and most fission products by taking advantage of the unique properties of uranium hexafluoride (UF₆). In the FLEX process, the used TRISO fuel is reacted with zirconium fluoride salt, forming UF₆ and the fluoride salts of the actinides and fission products. At process temperatures, the UF₆ volatizes into a gas, and is released from the molten salt mixture. This leaves behind the …

Preparation And Derivatization Of Novel Sydnonimines And Their Esters, Timothy Luke Teschler

Browse all Theses and Dissertations

Some years ago, we reported that 3-phenylsydnone underwent dilithiation to yield the dilithio species, upon treatment with n-butyllithium. Subsequent reactions with electrophiles led to variously substituted aryl sydnones, dependent on the nature of the electrophile employed. Sydnonimines, exocyclic nitrogen analogs of sydnones, exhibit interesting biological properties and, accordingly, it was of value to explore whether or not the dilithiation approach could be extended to such species. In the present work a series of N-6-ethoxycarbonyl-3-arylsydnonimines were synthesized from the corresponding sydnonimine hydrochlorides in moderate yields (22-77%). Attempted dilithiations of N-6-ethoxycarbonyl-3-arylsydnonimines and trapping with iodine proved to be problematic, yielding only the …

The Shape Of Pulverized Bituminous Vitrinite Coal Particles, Jonathan P. Mathews, Patrick G. Hatcher, Alan W. Scaroni

Chemistry & Biochemistry Faculty Publications

The shape of pulverized bituminous coal particles (vitrinites) was determined by optical and laser light scattering. Vitrain samples were collected from obvious tree remains located in the ceilings of two Appalachian coal mines. Wet sieving produced narrow size cuts. The particles were determined to be oblong or blocky in shape, with average length-to-width ratio of 1.7 and sphericity of 0.78. They were analogous in shape to a square ended, rectangular "house brick". The two bituminous coals and different size cuts of each coal had essentially the same shape parameters. Characteristic heating times and terminal velocities were higher by 22 and …

Fabrication Of Dna Microarrays On Poly (Methylmethacrylate) Substrates For Biomolecular Reporting, Catherine N. Situma

LSU Doctoral Dissertations

DNA microarrays require the use of substrates with well-established surface modification / probe attachment chemistries. Glass/quartz have been widely adopted as typical support materials since their surface modification chemistries which involve the use of siloxane –based chemistries have been widely studied however; these chemistry is susceptible to hydrolytic cleavage especially at high or low pH values. Recently, polymers have been sought as alternative microarray support materials but their surface modification strategies are not well characterized compared to glass. This report will entail surface photo-modification of PMMA polymer substrates by UV irradiation which produces functional scaffolds of carboxylic groups that allow …

Lanthanide Complexes As Fluorescent Indicators For Neutral Sugars And Cancer Biomarkers, Onur Alpturk

LSU Doctoral Dissertations

Simple water soluble lanthanum and europium complexes are effective at detecting neutral sugars as well as glyco- and phospholipids. In solutions at physiologically relevant pH the fluorescent lanthanum complex binds neutral sugars with apparent binding constants comparable to those of arylboronic acids. Interference from commonly occurring anions is minimal. The europium complex detects sialic acid-containing gangliosides at pH 7.0 over an asialoganglioside. This selectivity is attributed, in large part, to the cooperative complexation of the oligosaccharide and sialic acid residues to the metal center, based on analogous prior studies. In MeOH, lysophosphatidic acid (LPA), a biomarker for several pathological conditions …

Xanthene/Benzoxanthene Dyes: Novel Synthetic Metholologies, Applications In Molecular Recognition, Cellular Imaging And The Design Of A Tunable White (Rgb) Light Emitter, Youjun Yang

LSU Doctoral Dissertations

My graduate work has focused on the development of new fluorophore materials towards addressing several interdisciplinary research problems. Selective detection of sialic acid via a boron-amide interaction. Concentration changes of sialic acid can be monitored ratiometrically in the visible region using a boronic acid based chemosensor. The technique shows great promise for the detection of sialic acid, a critical cell surface residue involved in cancer, graft rejection and virulence in certain bacteria. There is no interference from commonly occurring oligosaccharides, aminosugars and most carboxylic acid-containing compounds. Improved synthetic methodology and studies of novel molecular probe architectures. I have developed a …

Syntheseses [Sic] And Evaluation Of Porphyrin Derivatives For Applications In Medicine And In Material Science, Erhong Hao

LSU Doctoral Dissertations

Chapter 1 presents a concise introduction to porphyrins, especially on the synthesis of meso-tetraphenylporphyrins, which were synthesized during the course of my research and were used for further purposes in the following chapters. Chapter 2 describes the synthesis of a series of cobaltacarborane-porphyrin conjugates for the boron neutron capture therapy (BNCT) of tumors. Using an efficient and high yield ring-opening reaction, N-substituted porphyrins were also synthesized. The spectroscopic and structural properties of these compounds are presented. These high percentage boron and amphiphilic compounds are promising boron delivery agents for BNCT (prelimary cellular studies using some of these compounds have been …

Hadron Models And Related New Energy Issues, Florentin Smarandache

Branch Mathematics and Statistics Faculty and Staff Publications

The present book covers a wide-range of issues from alternative hadron models to their likely implications in New Energy research, including alternative interpretation of lowenergy reaction (coldfusion) phenomena. The authors explored some new approaches to describe novel phenomena in particle physics. M Pitkanen introduces his nuclear string hypothesis derived from his Topological Geometrodynamics theory, while E. Goldfain discusses a number of nonlinear dynamics methods, including bifurcation, pattern formation (complex GinzburgLandau equation) to describe elementary particle masses. Fu Yuhua discusses a plausible method for prediction of phenomena related to New Energy development. F. Smarandache discusses his unmatter hypothesis, and A. Yefremov …

In Vivo Imaging Of Transport And Biocompatibility Of Single Silver Nanoparticles In Early Development Of Zebrafish Embryos, Kerry J. Lee, Prakash D. Nallathamby, Lauren M. Browning, Christopher J. Osgood, Xiao-Hong Nancy Xu

Chemistry & Biochemistry Faculty Publications

Real-time study of the transport and biocompatibility of nanomaterials in early embryonic development at single-nanoparticle resolution can offer new knowledge about the delivery and effects of nanomaterials in vivo, and provide new insights into molecular transport mechanisms in developing embryos. In this study, we directly characterized the transport of single silver nanoparticles into an in vivo model system (zebrafish embryos) and investigated their effects on early embryonic development at single-nanoparticle resolution in real time. We designed highly purified and stable (not aggregated and no photodecomposition) nanoparticles and developed single-nanoparticle optics and in vivo assays to enable the study. We …

Matrix Effects, Development Of Clean-Up And Lc-Techniques Contributing Towards A Reference Lcms Method For The Analysis Of Lipophilic Marine Toxins, Mairead Anne Mcelhinney

Masters

The most widely used reference method in Europe for the detection and monitoring of lipophilic marine toxins is the Mouse Bioassay (MBA) as first described by Yasumoto et al., (1978). The MBA offers a good level of protection to human health and is capable of detecting the overall toxicity of previously known toxins. However, there are drawbacks associated with the use of the MBA as it is both expensive and time consuming and can give false positives due to interferences (Suzuki et al, 1976). The problems associated with the original mouse bioassay have led to several modifications (Yasumoto et al, …

Controlling The Diastereoselectivity In The Microwave-Assisted Aza-Cope Rearrangement--Mannich Cyclization, Wesley A. Turley

Master's Theses and Doctoral Dissertations

No abstract provided.

Kinetic Studies Of The Hydrolysis Reactions Of Ruthenium (Iii) Complexes Him Trans-[Rucl₄(Im)₂] And Hind Trans-[Rucl₄(Ind)₂] By Uv-Visible Spectrophotometry, Pramod K. Nangunuri

Master's Theses and Doctoral Dissertations

The ruthenium complexes have gained importance in cancer research in recent times, as several cancers have developed resistance towards platinum compounds. Platinum compounds have severe adverse effects that limited their use towards a wide range of tumors.

Ruthenium complexes are considered as pro-drugs, as they transform into antitumor active species in the body by hydrolysis, redox reactions, and reactions with biologically occurring nucleophiles. My project involved the synthesis of two ruthenium complexes with different ligands and the study of the hydrolysis reactions under different pH at room temperature using UV-visible spectrophotometry.

These studies will enable us to understand how structural …

Synthesis And Solid State F-Nmr Studies On Fluorine-Labeled Antimicrobial Peptide Rk-21, Mahender Budarapu

Master's Theses and Doctoral Dissertations

Antimicrobial peptides act against bacteria by binding non-specifically and disrupting their outer membrane. LL-37 is the only member of the cathelicidin group of antimicrobial peptides present in humans and shows a broad range of antimicrobial activity. RK-21 is a fragment of human antimicrobial peptide LL-37, which is α-helical, cationic and amphipathic in nature. RK-21 displays similar antimicrobial activity to LL- 37. In order to understand the mechanism of lipid bilayer disruption, fluorine-labeled antimicrobial peptide RK-21 was chemically synthesized and 19F-NMR studies were done. NMR studies were done at various peptide concentrations, on different lipid bilayer compositions and temperatures. 31P-NMR studies …

Characterization Of A Black Coating Overlying Rock Paintings Found In Little Lost River Cave, Idaho Using Thm-Gc-Ms, Jamie Brown-Sinha

Master's Theses and Doctoral Dissertations

A black coating overlies rock paintings found within Little Lost Rive Cave, Idaho. A calibrated radiocarbon date of 1390-1040 B.C. was obtained by Steelman et al.1 However, this relies on the assumption that the black coating was formed by some human activity. For further characterization and to verify that the coating is anthropogenic, THM-GC-MS was performed on various samples collected throughout the cave, including soil samples from inside, outside, and above the cave. Humic and fulvic acids, synthetic and natural melanin, and experimentally created cooking residues were also analyzed as standard materials. By comparing the resulting chromatograms and the compounds …

Interaction Between Metal Fission Products And Triso Coating Materials, Clemens Heske

Fuels Campaign (TRP)

This project focuses on the chemical bonding and interface formation of metal fission products with the coating materials used in tri-isotropic (TRISO) fuel particles for gas-cooled reactors. By combining surface- and bulk-sensitive spectroscopic methods, intermediate chemical phases at the interface, intermixing/ diffusion behavior, and the electronic interface structure as a function of material (metal and coating materials) and temperature are examined.

In the past year, emphasis was placed on a detailed analysis and description of the Cs/SiC interface formation process.

Criticality Studies For Urex Processes, Denis Beller

Separations Campaign (TRP)

The completion of criticality experiments for mixtures of transuranic actinides (TRU–includes Np, Pu, Am, and Cm) that will be created during the separation of used nuclear fuel may be a requirement in order to construct prototype plants for the Global Nuclear Energy Partnership. In this program and the Advanced Fuel Cycle Research and Development (AFC R&D) program that supports it, economic and environmental methods are being developed to reduce the impact of waste from commercial nuclear fuel cycles.

Recycling of used fuel by chemically separating it into U, fission products, and TRU would be the first step in this new …