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2010

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Articles 601 - 630 of 950

Full-Text Articles in Chemistry

Synthesis Of Novel Borinic Acids As Potential Hiv-1 Protease Inhibitors, Donald Ray Clayton Iii Jan 2010

Synthesis Of Novel Borinic Acids As Potential Hiv-1 Protease Inhibitors, Donald Ray Clayton Iii

Undergraduate Honors Theses

Implementation of antiretroviral treatment has drastically increased both the survival and quality of life of HIV/AIDS patients. While there has been significant success using these life saving drugs, several problems have arisen during their use. Among these major setbacks included the rising incidences of resistance, low bioavailability, and an unacceptable level of toxicity. Consequently, there is an urgent need for the development and production of new inhibitory compounds with increased resistance profiles, higher bioavailability, and decreased toxicity. Recent studies have demonstrated that boron modified peptides are effective inhibitors of aspartic proteases. Furthermore, these boronated compounds have exhibited dual-inhibition along with …


Geochemical Investigation Of An Offshore Sewage Sludge Deposit, Barcelona, Catalonia, Spain, Michael A. Kruge, Albert Permanyer, Jordi Serra, Danlin Yu Jan 2010

Geochemical Investigation Of An Offshore Sewage Sludge Deposit, Barcelona, Catalonia, Spain, Michael A. Kruge, Albert Permanyer, Jordi Serra, Danlin Yu

Department of Earth and Environmental Studies Faculty Scholarship and Creative Works

For 20 years ending in the 1990’s the city of Barcelona discharged the products from a large primary sewage treatment plant directly into the Mediterranean Sea via underwater conduits. About ca. 3 million m3 of relict sewage sludge, rich in organic matter and heavy metals, has spread over an elongated area offshore, due to successive ruptures of the conduits. The use of the discharge pipes ceased, but he sludge deposit remains in place for the time being.

To understand the history and present state of the sludge deposit in advance of future remediation, a program of geophysical mapping, sampling, …


The Synthesis, Structure, And Properties Of Group 2 Poly(Pyrazolyl)Borates And Their Use For The Atomic Layer Deposition Of Group 2 Borates, Mark J. Saly Jan 2010

The Synthesis, Structure, And Properties Of Group 2 Poly(Pyrazolyl)Borates And Their Use For The Atomic Layer Deposition Of Group 2 Borates, Mark J. Saly

Wayne State University Dissertations

A series of heavy alkaline earth complexes containing TpR2-based ligands has been synthesized, structurally characterized, and their properties were investigated. Salt metathesis routes involving MI2 (M = Ca, Sr, Ba) with either KTpEt2 or KTpnPr2 afforded MTpEt22 or MTpnPr22 in good to moderate yields. All of these complexes are volatile and exceptionally thermally stable, and have acceptable properties for use as group 2 atomic layer deposition (ALD) precursors. In addition, a series of group 2 complexes containing BpR2-based ligand systems were synthesized. Treatment of MI2 (M = Ca, Sr, Ba) with two equivalents of TlBptBu2, KBp, and KBpiPr2 in tetrahydrofuran …


I. Microwave-Influenced Diversity-Oriented Synthesis Of Biologically Relevant Small & Natural-Product-Like Molecules Via Multicomponent Coupling Reactions Ii. Synthetic Studies Toward The Total Synthesis Of The Repeating Tetrasaccharide Unit Of Zwitterionic Polysaccharide Ps A1, Soumava Santra Jan 2010

I. Microwave-Influenced Diversity-Oriented Synthesis Of Biologically Relevant Small & Natural-Product-Like Molecules Via Multicomponent Coupling Reactions Ii. Synthetic Studies Toward The Total Synthesis Of The Repeating Tetrasaccharide Unit Of Zwitterionic Polysaccharide Ps A1, Soumava Santra

Wayne State University Dissertations

Microwave-influenced diversity-oriented synthesis of biologically relevant small and natural-product-like molecules via multicomponent coupling reactions (MCCRs) have been investigated. Cheap, readily available starting materials in conjunction of microwave irradiation and employment of environmentally benign solvent (e.g. water) provided a common platform that allowed to access a wide array of structurally and skeletally diverse molecules. The investigation allowed us to establish a new paradigm of diversity-activity relationships (DARs) by tuning reacting components of the MCCRs and proved that in contrary to the conventional use of microwave as a rate accelerating tool, it can be used to influence reactivity of molecules. The method …


Polystyrene-Supported Aluminum Chloride As An Efficient And Reusable Catalyst For Condensation Of Indole With Various Carbonyl Compounds, Bahman Tamami, Amir Nasrolahi Shirazi, Kaveh Parvanak Borujeni Jan 2010

Polystyrene-Supported Aluminum Chloride As An Efficient And Reusable Catalyst For Condensation Of Indole With Various Carbonyl Compounds, Bahman Tamami, Amir Nasrolahi Shirazi, Kaveh Parvanak Borujeni

Pharmacy Faculty Articles and Research

Crosslinked polystyrene-supported aluminum chloride (PS-AlCl3) is a stable, recyclable and environmental friendly heterogeneous catalyst for the condensation of indole with aldehydes and ketones to afford diindolylmethanes. In addition, PS-AlCl3 shows satisfactory selectivity in the reaction of mixtures of an aldehyde and a ketone with indole. Although AlCl3 is a water sensitive, corrosive and environmentally harmful compound, PS-AlCl3 is a stable and water-tolerant species. The mild reaction conditions, short reaction times, easy work-up, high to excellent yields, chemoselectivity, reuse of the catalyst for at least ten times without significant change in its catalytic activity, low cost, and easy preparation and handling …


Reduced Electronic Spaces For Modeling Donor/Acceptor Interactions, Robert J. Cave, Stephen T. Edwards '06, John A, Kouzelos '07, Marshall D. Newton Jan 2010

Reduced Electronic Spaces For Modeling Donor/Acceptor Interactions, Robert J. Cave, Stephen T. Edwards '06, John A, Kouzelos '07, Marshall D. Newton

All HMC Faculty Publications and Research

Diabatic states for donor (D) and acceptor (A) interactions in electron transfer (ET) processes are formulated and evaluated, along with coupling elements (HDA) and effective D/A separation distances (rDA), for reduced electronic spaces of variable size, using the generalized Mulliken Hush model (GMH), applicable to an arbitrary state space and nuclear configuration, and encompassing Robin−Day class III and as well as class II situations. Once the electronic state space is selected (a set of n ≥ 2 adiabatic states approximated by an orbital space based on an effective 1-electron (1-e) Hamiltonian), the charge-localized GMH …


Effects Of Silver Nanoparticles On Photochemical Processes Focusing On Luminol Chemiluminescence, Scott Milam Jan 2010

Effects Of Silver Nanoparticles On Photochemical Processes Focusing On Luminol Chemiluminescence, Scott Milam

Master's Theses and Doctoral Dissertations

Silver nanoparticles of varying sizes were synthesized. Their effects on enhancing or quenching the photochemical processes of tryptophan fluorescence, a ruthenium complex decay constant and chemiluminescence of luminol and ferricyanide, were studied. The tryptophan fluorescence was slightly enhanced by smaller nanoparticles and showed slight quenching in the presence of larger nanoparticles. The tris (2,2’-bipyridyl ruthenium (II) chloride) complex was excited using a 532 nm laser, and the decay constant was measured. Neither gold nor silver nanoparticles showed an impact on this process. The luminol chemiluminescence was studied with an emphasis on holding the concentration of nanoparticles, surface area, and silver …


Characterization Of The Binders In The Rock Art Of Cueva La Conga, Nicaragua, Ran Li Jan 2010

Characterization Of The Binders In The Rock Art Of Cueva La Conga, Nicaragua, Ran Li

Master's Theses and Doctoral Dissertations

Cueva La Conga is the only known painted cave in Nicaragua, in a part of that country about which little is known archaeologically. The rock art, which includes carved rock formations as well as paintings and handprints, may provide clues about the past people and culture of this area. Archaeologists want to know if the paintings were influenced by the Maya to the north, or the Caribbean cultures to the east, or were a purely indigenous development. Determining the age of the paintings will help to understand the possible cultural relationships between known cultures and the rock art of Cueva …


Chemical Bath Deposition And Electrodeposition Of Epitaxial Semiconductor Materials For Application In Photovoltaic Devices, Guojun Mu Jan 2010

Chemical Bath Deposition And Electrodeposition Of Epitaxial Semiconductor Materials For Application In Photovoltaic Devices, Guojun Mu

Doctoral Dissertations

"This dissertation investigates the chemical bath deposition of zinc oxide and electrodeposition of cuprous iodide on polycrystalline and single crystal substrates. Paper I describes the chemical bath deposition and characterization of titled epitaxial zinc oxide nanospears on Si(001) single crystal substrate. In Paper II, the chemical bath deposition of zinc oxide nanospears from highly alkaline solutions is discussed in detail, including a thermodynamic calculation of saturation and speciation of Zn(II) in aqueous solution, and a kinetic study of the deposition process. In this paper the epitaxial zinc oxide is reported grown on Au(100), (110), and (111) single crystals. Paper III …


Capillary Electrophoresis Of Pteridines In Urine And Plants And Quantification Of Pharmaceutical And Personal Care Products In Missouri Waste Water, Stephen E. Gibbons Jan 2010

Capillary Electrophoresis Of Pteridines In Urine And Plants And Quantification Of Pharmaceutical And Personal Care Products In Missouri Waste Water, Stephen E. Gibbons

Doctoral Dissertations

"Capillary electrophoresis (CE) is a powerful technique that separates molecules based on their respective charge and hydrodynamic size. The major advantages of CE are high separation efficiency, small sample volume requirements, simple to no sample preparation and often organic solvents are not required for the separation.

The work presented in this dissertation utilized capillary electrophoresis for the analysis two different classes of compounds in different matrices. The first project investigated pteridines in urine and plants. The second project investigated pharmaceutical and personal care products (PPCP's) in Missouri waste water.

As cancer continues to be one of the top three causes …


Samuel J. Danishetsky And The Synthesis Of Globo-H Antigen, Chelsey Jones Jan 2010

Samuel J. Danishetsky And The Synthesis Of Globo-H Antigen, Chelsey Jones

Natural Sciences Student Research Presentations

Samuel J. Danishefsky is a research scientist at the Sloan-Kettering Institute. He uses his knowledge in organic chemistry to make biological advances in cancer research. Danishefsky has been conducting research and experiments on synthesizing anti-cancer vaccines with the use of carbohydrate antigens. Danishefsky has also been conducting research and experiments on homogeneous erythropoietin which could provide insight into how glycoproteins function. Knowledge of glycoprotein would allow scientists to better understand erythropoietin which can treat anemia in chemotherapy patients. All is valuable information in advances in cancer research and cancer research is important because it is a major disease affecting the …


Synthesis And Uses Of Polycarbonate, Hai Bui Jan 2010

Synthesis And Uses Of Polycarbonate, Hai Bui

Natural Sciences Student Research Presentations

Polycarbonate is one of the most important polymers being used today. Polycarbonate has many important characteristics that prove to be useful in its applications. Some characteristics of polycarbonate are that it is clear, light weight, and durable. The optical properties and the specific weight index of polycarbonate make it ideal for lens material in eyeglasses. There are two main ways of commercially synthesizing polycarbonate from bisphenol A. It can be synthesized through the process of solvent interfacial polymerization or through melt transeterification. Both processes are different and each has its own benefits.


Targeting Base Excision Repair Suggests A New Therapeutic Strategy Of Fludarabine For The Treatment Of Chronic Lymphocytic Leukemia, A. D. Bulgar, M. Snell, J. R. Donze, E. B. Kirkland, Lan Li, Shuming Yang, Yan Xu, S. L. Gerson, Lili Liu Jan 2010

Targeting Base Excision Repair Suggests A New Therapeutic Strategy Of Fludarabine For The Treatment Of Chronic Lymphocytic Leukemia, A. D. Bulgar, M. Snell, J. R. Donze, E. B. Kirkland, Lan Li, Shuming Yang, Yan Xu, S. L. Gerson, Lili Liu

Chemistry Faculty Publications

No abstract provided.


Biointeraction Analysis By High-Performance Affinity Chromatography: Kinetic Studies Of Immobilized Antibodies, Mary Anne Nelson, Annette C. Moser, David S. Hage Jan 2010

Biointeraction Analysis By High-Performance Affinity Chromatography: Kinetic Studies Of Immobilized Antibodies, Mary Anne Nelson, Annette C. Moser, David S. Hage

David Hage Publications

A system based on high-performance affinity chromatography was developed for characterizing the binding, elution and regeneration kinetics of immobilized antibodies and immunoaffinity supports. This information was provided by using a combination of frontal analysis, split-peak analysis and peak decay analysis to determine the rate constants for antibody–antigen interactions under typical sample application and elution conditions. This technique was tested using immunoaffinity supports that contained monoclonal antibodies for 2,4-dichlorophenoxyacetic acid (2,4-D). Association equilibrium constants measured by frontal analysis for 2,4-D and related compounds with the immobilized antibodies were 1.7–12 × 106 M−1 at pH 7.0 and 25 °C. Splitpeak …


A General Approach For Receptor And Antibody-Targeted Detection Of Native Proteins Utilizing Split-Luciferase Reassembly, Cliff I. Stains, Jennifer L. Furman, Jason R. Porter, Srivats Rajagopal, Richard T. Wyatt, Indraneel Ghosh Jan 2010

A General Approach For Receptor And Antibody-Targeted Detection Of Native Proteins Utilizing Split-Luciferase Reassembly, Cliff I. Stains, Jennifer L. Furman, Jason R. Porter, Srivats Rajagopal, Richard T. Wyatt, Indraneel Ghosh

Cliff Stains Publications

The direct detection of native proteins in heterogeneous solutions remains a challenging problem. Standard methodologies rely on a separation step to circumvent nonspecific signal generation. We hypothesized that a simple and general method for the detection of native proteins in solution could be achieved through ternary complexation, where the conditional signal generation afforded by split-protein reporters could be married to the specificity afforded by either native receptors or specific antibodies. Toward this goal, we describe a solution phase split-luciferase assay for native protein detection, where we fused fragmented halves of firefly luciferase to separate receptor fragments or single-chain antibodies, allowing …


Post-Coring Entrapment Of Modern Air In Some Shallow Ice Cores Collected Near The Firn-Ice Transition: Evidence From Cfc-12 Measurements In Antarctic Firn Air And Ice Cores, Murat Aydin, S. A. Montzka, M. O. Battle, M. B. Williams, Warren J. De Bruyn, J. H. Butler, K. R. Verhulst, C. Tatum, B. K. Gun, D. A. Plotkin, B. D. Hall, Eric S. Saltzman Jan 2010

Post-Coring Entrapment Of Modern Air In Some Shallow Ice Cores Collected Near The Firn-Ice Transition: Evidence From Cfc-12 Measurements In Antarctic Firn Air And Ice Cores, Murat Aydin, S. A. Montzka, M. O. Battle, M. B. Williams, Warren J. De Bruyn, J. H. Butler, K. R. Verhulst, C. Tatum, B. K. Gun, D. A. Plotkin, B. D. Hall, Eric S. Saltzman

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

In this study, we report measurements of CFC-12 (CCl2F2) in firn air and in air extracted from shallow ice cores from three Antarctic sites. The firn air data are consistent with the known atmospheric history of CFC-12. In contrast, some of the ice core samples collected near the firn-ice transition exhibit anomalously high CFC-12 levels. Together, the ice core and firn air data provide evidence for the presence of modern air entrapped in the shallow ice core samples that likely contained open pores at the time of collection. We propose that this is due to closure of the open pores …


Electrowetting Of Ionic Liquids And Development Of An Electrowetting Based Tunable Rc Filter And Its Uses As An Analytical Detector, Yasith Sameera Nanayakkara Jan 2010

Electrowetting Of Ionic Liquids And Development Of An Electrowetting Based Tunable Rc Filter And Its Uses As An Analytical Detector, Yasith Sameera Nanayakkara

Chemistry & Biochemistry Dissertations - Archive

Wettability control of a liquid drop by an external electric field or "electrowet- ting" recently was the subject of special interest among researchers due to its util- ity for a variety of applications. Some of these include "electrowetting on dielectric (EWOD)" based digital microfluidic lab-on-a-chip devices, EWOD lenses and EWOD displays. In these EWOD based devices, water or aqueous electrolytes are used as the liquid medium. However, the use of water or aqueous electrolytes has several limitations and may reduce the efficiency as well as accuracy of these devices. Low thermal stability, evaporation, fouling and fixed phys- iochemical properties are …


Enantiomeric Chromatographic Separations And Ionic Liquids In Gas Chromatography, Ke Huang Jan 2010

Enantiomeric Chromatographic Separations And Ionic Liquids In Gas Chromatography, Ke Huang

Chemistry & Biochemistry Dissertations - Archive

Due to the different therapeutic values of optical isomers, the production of enantiomerically pure drugs is of growing demand in pharmaceutical, biotechnology, and agrochemical industries. Today, gas chromatography (GC) and high performance liquid chromatography (HPLC) are the most prevalent analytical techniques for the enantiomeric separation of chiral molecules. Although the two techniques can have very different separation mechanisms, they are highly complementary to each other. Together, they can accomplish enantiomeric separations for large numbers of compounds of different functionalities. A great variety of chiral stationary phases (CSPs) have been developed over the years. However, since they are the heart of …


Toxicodynamics And Biotransformation Of Azaspiracids Incorporating Liquid Chromatography-Tandem-Mass Spectrometry (Lc-Ms/Ms) Techniques., Daniel O'Driscoll Jan 2010

Toxicodynamics And Biotransformation Of Azaspiracids Incorporating Liquid Chromatography-Tandem-Mass Spectrometry (Lc-Ms/Ms) Techniques., Daniel O'Driscoll

Theses

Azaspiracids (AZAs) are a family of lipophilic polyether marine biotoxins, that have caused a number of human intoxication incidents in Europe since 1995, which was the first incident reported following the consumption by consumers of intoxicated shellfish {Mytilus edulis). This class of phycotoxins has been responsible for extended closures of shellfisheries in various locations around Europe, where levels of AZAl-3 are regulated in shellfish. Since their discovery in 1995, AZAs have become the focus of extensive research, resulting in the discovery of numerous analogues. Only AZAl and AZA2 have been found in phytoplankton and all the other analogues are believed …


Application Of Liquid Chromatography - Tandem Mass Spectrometry For The Determination Of Veterinary Drug Residues In Food Of Animal Origin, Brian Kinsella Jan 2010

Application Of Liquid Chromatography - Tandem Mass Spectrometry For The Determination Of Veterinary Drug Residues In Food Of Animal Origin, Brian Kinsella

Theses

The QuEChERS (quick, easy, cheap, effective, rugged and safe) sample preparation approach was evaluated for the extraction of anthelmintic residues from bovine milk and tissues. Liquid chromatography coupled to tandem mass spectrom.etry (LC- MS/MS) was used for detection and quantification of residues, which included the benzimidazoles (BZs), macrocyclic lactones (MLS) and the generally overlooked flukicides.

Initial work focused on the optimisation of a QuEChERS method to effectively extract anthelmintic residues from milk and liver. The method involves the extraction of residues with acetonitrile (MeCN) in the presence of salts (MgS04 and NaCl) to induce phase separation. After shaking and centrifugation, …


Molecular Structure Of Fac-Aquadichlorotris(Dimethylsulfoxide)Ruthenium(Ii), L. Foster, J. Hardin, Mark Draganjac, B. C. Noll Jan 2010

Molecular Structure Of Fac-Aquadichlorotris(Dimethylsulfoxide)Ruthenium(Ii), L. Foster, J. Hardin, Mark Draganjac, B. C. Noll

Journal of the Arkansas Academy of Science

No abstract provided.


Development Of Metal-Based Luminescent Probes For Applications In Biomolecular Structure And Dynamics, Ayesha Sharmin Jan 2010

Development Of Metal-Based Luminescent Probes For Applications In Biomolecular Structure And Dynamics, Ayesha Sharmin

Graduate Student Theses, Dissertations, & Professional Papers

New transition-metal complexes containing luminescent properties have been designed and synthesized for application as structural probes for biomolecules. Potential DNA intercalators, 2- amino-anthracene substituted triosmium clusters, were synthesized by the reactions of 2-aminoanthracene with [Os3(CO)10(CH3CN)2]. The products [Os3(CO)10(μ-η2-(N-C(1))-NH2C14H8)(μ- H)], [Os3(CO)10(μ-η2-(N-C(3))-NHC14H9)(μ-H)], [Os3(CO)9(μ-η2-(N-C(3))-NHC14H8)(μ-H)2] and [Os3(CO)9(μ3-η2-(N-C(3))-NHC10H9)(μ-H)] obtained from this reaction have been structurally characterized by spectroscopic, photophysical and electrochemical techniques. Solid state structures are also reported for the complexes [Os3(CO)10(μ-η2-(N-C(3))-NHC14H9)(μ-H)] and [Os3(CO)9(μ-η2-(N-C(3))-NHC14H8)(μ-H)2]. To investigate bio-macromolecular dynamics on the sub-microsecond-to-microsecond timescale, a series of ruthenium based mono-nuclear metalligand charge-transfer complexes (MLCs) of formula [XRu(CO)(L–L)(L′)2][PF6] (X = H, TFA, Cl; L–L = 2,2′-bipyridyl, 1,10-phenanthroline, 5-amino-1,10-phenanthroline …


Analysis Of The Electron Withdrawing Capability Of Acetylene Groups For Promoting Nucleophilic Aromatic Substitution, Eric D. Braunstein Jan 2010

Analysis Of The Electron Withdrawing Capability Of Acetylene Groups For Promoting Nucleophilic Aromatic Substitution, Eric D. Braunstein

Honors Theses

It is well known that electron withdrawing groups, such as nitro or carbonyl groups, activate benzene rings for nucleophilic aromatic substitution. However, little research has been done to investigate the electron withdrawing capability of acetylene groups for substitution of aromatic halides. Experimental and computational investigations on the reactivity of halogenated phenylacetylenes with oxygen and other nucleophiles will be described.


Cellular Distribution Of Activity For Three Enzymes With Maltose Binding Protein As Fusion Partner And The Structural Implications, Özde F. Ütkür, Berna Sariyar Akbulut, Amable Hortaçsu Jan 2010

Cellular Distribution Of Activity For Three Enzymes With Maltose Binding Protein As Fusion Partner And The Structural Implications, Özde F. Ütkür, Berna Sariyar Akbulut, Amable Hortaçsu

Turkish Journal of Chemistry

The bacterial SEC pathway is commonly used for secretion of heterologous proteins in E. coli by fusing them to transported proteins to facilitate downstream processing. While some proteins are translocated very efficiently, some reside in the cytoplasm. In this work, maltose binding protein (MBP) was fused to 3 cytoplamic enzymes from Thermus thermophilus (serine protease, 251 residues; glucose isomerase, 381 residues; pullulanase, 718 residues) to study the protein transport from the cytoplasm by quantifying the distribution of activities in different cellular compartments. Pullulanase activity was harvested exclusively in the periplasm; however, glucose isomerase activity was harvested exclusively in the cytoplasm. …


Study Of Catalytic Activities Of Nanostructure Copper And Cobalt Supported Zsm-5 Catalysts For Conversion Of Volatile Organic Compounds, Aligholi Niaei, Dariush Salari, Seyed Ali Hosseini Jan 2010

Study Of Catalytic Activities Of Nanostructure Copper And Cobalt Supported Zsm-5 Catalysts For Conversion Of Volatile Organic Compounds, Aligholi Niaei, Dariush Salari, Seyed Ali Hosseini

Turkish Journal of Chemistry

This paper reports the comparison of the activities of nanostructure Cu-ZSM-5 and Co-ZSM-5 catalysts for conversion of ethyl acetate and toluene and deals with the relationship between activity and structure of catalysts. The catalysts were characterized by ICP-AES, XPS, EDX, XRD, SEM, and TEM techniques. Catalytic studies were carried out under atmospheric pressure and in a temperature range of 200-500 °C. Cu-ZSM-5 catalysts showed better activity than Co-ZSM-5, revealing higher activity of copper cations. The higher activity was ascribed to higher electro-negativity, smaller cation radius, good distribution, and specific coordination of copper cations inside Cu-ZSM-5 catalysts. The activity of catalysts …


Synthesis, Characterization, And Application Of Nanoporous Materials Based On Silicon- Or Halogen-Containing Spiroketal And Spirothioketal Polymers, Hamada H. Abdel-Razik Jan 2010

Synthesis, Characterization, And Application Of Nanoporous Materials Based On Silicon- Or Halogen-Containing Spiroketal And Spirothioketal Polymers, Hamada H. Abdel-Razik

Turkish Journal of Chemistry

Organic microporous materials based on silicon-containing spiroketal and spirothioketal polymers were synthesized via a 1,3-dioxol-forming polymerization reaction between 1,1a,4,4a,5,5a,8, 8a-octahydro-2,3,6,7-tetra(trimethylsilyl)-9,10-anthraquinone and different types of polyol or polythiol. These silicon-containing polymers were subjected to bromination to yield bromine-containing polymers. The structures of the prepared polymers were confirmed by NMR spectroscopy and molecular mass measurements. Nitrogen adsorption/desorption isotherms of the prepared polymers showed that a large amount of nitrogen was adsorbed at low relative pressure, indicating microporosity. These polymers have BET surface areas in the range of 505-830 m^2 g^{-1}. These polymers were determined to be useful for pervaporation separation of phenol/water …


Characterization Of Chitosan In Acetic Acid: Rheological And Thermal Studies, Esam A. El-Hafian, Elham S. Elgannoudi, Azizah Mainal, Abdul Haamid Bin Yahaya Jan 2010

Characterization Of Chitosan In Acetic Acid: Rheological And Thermal Studies, Esam A. El-Hafian, Elham S. Elgannoudi, Azizah Mainal, Abdul Haamid Bin Yahaya

Turkish Journal of Chemistry

This study examined the influence of temperature, concentration, shearing time, and storage time on the rheological properties, i.e. the dynamic viscosity and shear stress, as a function of shear rate of chitosan solubilized in weakly acid solutions. The results showed that shear thinning behavior (pseudoplastic non-Newtonian behavior) was pronounced at temperatures from 20 to 50 °C, but was more remarkable at lower temperature. In addition, the activation energy value derived from ln \eta vs. 1/T data was found to be 20.86 kJ mol^{-1}. When the effect of concentration was studied, the shear thinning behavior was pronounced at all concentrations. The …


Synthesis Of Some Pyridazine Derivatives Carrying Urea, Thiourea, And Sulfonamide Moieties And Their Antimicrobial Activity, Deni̇z S. Doğruer, Şölen Urlu, Ti̇jen Önkol, Berri̇n Özçeli̇k, M. Fethi̇ Şahi̇n Jan 2010

Synthesis Of Some Pyridazine Derivatives Carrying Urea, Thiourea, And Sulfonamide Moieties And Their Antimicrobial Activity, Deni̇z S. Doğruer, Şölen Urlu, Ti̇jen Önkol, Berri̇n Özçeli̇k, M. Fethi̇ Şahi̇n

Turkish Journal of Chemistry

Some pyridazine derivatives carrying urea, thiourea, and sulfonamide groups were synthesized and evaluated for their antimicrobial activity against gram-positive and gram-negative bacteria, and fungi by using broth microdilution. The structures of these new compounds were confirmed by ^1H-NMR, mass spectrum, and elemental analysis. The synthesized compounds exhibited generally promising inhibitory activity against S. aureus (MIC ranging from 2 to 4 \mu g/mL) and E. coli (MIC ranging from 4 to 16 \mu g/mL). Moreover, all compounds showed antifungal activity against both C. albicans and C. parapsilosis, with a MIC value of 8 \mu g/mL.


Influence Of Alcl_3 On The Optical Properties Of New Synthesized 3-Armed Poly(Methyl Methacrylate) Films, Adnan Kurt Jan 2010

Influence Of Alcl_3 On The Optical Properties Of New Synthesized 3-Armed Poly(Methyl Methacrylate) Films, Adnan Kurt

Turkish Journal of Chemistry

Three-armed poly(methyl methacrylate)[PMMA] was synthesized by atom transfer radical polymerization at 100 °C using benzene-1,3,5-triyl tris(4-(bromomethyl) benzoate as 3-armed initiator and a cuprous(I) bromide/2,2'-bipyridine catalytic system. The characterization of PMMA was confirmed by FT-IR, ^1H-NMR, GPC, DSC, and TGA techniques. Optical absorption measurements were also studied by UV-VIS technique. Transmittance and reflectance measured in the wavelength range 300-700 nm were used to calculate the optical constants. The changes in dispersion and Urbach parameters were investigated as a function of AlCl_3 content. The wide band tails increased in width and the optical energy gap decreased from 2.39 to 1.28 eV as …


Synthesis And Characterization Of New Optically Active Polyamides Containing 2-(4-Nitro-1,3-Dioxoisoindolin-2-Yl)Succinic Acid And Aromatic Diamines Via Direct Polycondensation, Khalil Faghihi, Morteza Absalar, Mohsen Hajibeygi Jan 2010

Synthesis And Characterization Of New Optically Active Polyamides Containing 2-(4-Nitro-1,3-Dioxoisoindolin-2-Yl)Succinic Acid And Aromatic Diamines Via Direct Polycondensation, Khalil Faghihi, Morteza Absalar, Mohsen Hajibeygi

Turkish Journal of Chemistry

A new class of optically active polyamides (PAs) (6a-e) having 4-nitro-1,3-dioxoisoindolin-2-yl pendent groups were prepared by direct polycondensation reaction of 2-(4-nitro-1,3-dioxoisoindolin-2-yl) succinic acid (4) with various aromatic diamines in a medium consisting of triphenyl phosphite, calcium chloride, pyridine, and N-methyl-2-pyrrolidone. The resulting new polymers were obtained in high yields with inherent viscosities ranging between 0.32 and 0.48 dL/g, and were characterized by elemental analysis, FT-IR spectroscopy, specific rotation, solubility tests, and thermogravimetric analysis techniques (TGA and DTG). Bulky pendent groups of the polymer chains disturb interchain and intrachain interactions and make these PAs readily soluble in polar organic solvents such …