Chemistry Commons^™

Synthesis, Characterization And Molecular Dynamic Simulations Of Aqueous Choline Chloride Deep Eutectic Solvents, Sampson Asare

Electronic Theses and Dissertations

Various forms of deep eutectic solvents have been synthesized with advantages of 100% atom economy, low vapor pressure, ease of preparation, cost efficiency, low toxicity, and tunability. Though several DESs have been synthesized and characterized, including binary and ternary solvents, none of the binary DESs have been formulated with water as the sole hydrogen bond donor(HBD). This is due to a couple of opinions. First, water is disruptive to the eutectic bond in tertiary DES. Secondly, the ubiquity and concentration of water even in natural systems have led to the assertion that a solution rather than a eutectic solvent will …

A Comprehensive Analysis Of Aromatic-Proton Mediated Hydrogen Bonds, Mona S. Alshamrani

Electronic Theses and Dissertations

Hydrogen bonds play critical role in folding, structure and recognition of biological macromolecules (e.g., proteins, RNA, DNA). In addition to classical hydrogen bonds (e.g., ─OH---O=, ─OH---O─, ─NH---O─ etc.), structural analysis of protein and nucleic acids, almost a decade ago, showed that hydrogen bonds (e.g., CH---O) with hydrogen atoms on aliphatic carbon atoms (hereafter, aliphatic-protons) also play very important role in the structure and function of biomolecules. Even though, protons of aromatic ring systems (hereafter, aromatic-protons) are more polar than the aliphatic-protons, systematic analysis of hydrogen bonds of aromatic-protons have not been carried out. Therefore, I carried out a systematic analysis …

Development Of A High Performance Liquid Chromatography Method For The Analysis Of Next-Generation Cyanide Antidote, 3-Mercaptopyruvate, In Plasma, Elaf Alzhrani

Electronic Theses and Dissertations

Although the current FDA approved cyanide antidotes (i.e., sodium nitrite, sodium thiosulfate, and hydoxocoboalamine) are effective for treating cyanide poisoning, each individual antidote has major limitations, including large effective dosage, delayed onset of action, or dependence on enzymes generally confined to specific organs. To overcome these current limitations, next-generation cyanide antidotes are being investigated, including 3-mercaptopyruvate (3-MP). Analytical methods capable of detecting 3-MP from plasma are essential for the development of 3-MP as a nextgeneration cyanide antidote. Although 3-MP has been analyzed by LC-MS-MS, this instrument is not widely available. Therefore, a high performance liquid chromatography (HPLC) method with fluorescence …

Molecular Level Encapsulation Of Chromophores Using Pillar[5]Arenes For Enhanced Photostability, Manik Gudimani

Electronic Theses and Dissertations

Organic π-conjugated materials have been researched extensively for a number of applications including organic photovoltaics, electrooptic (EO) modulation, solid-state lasing, organic light emitting diodes (OLEDs), biological imaging and sensing, chemical sensing and ligands for photocatalysts. These organic optoelectronic materials have one major issue that affects its performance and lifetime—photostability. For some applications, hermetical packaging, which is expensive, is required to prevent degradation by light and oxygen. Photooxidation occurs when a material is exposed to light and causes structural and chemical changes leading to photodegradation of the material. The two primary degradation mechanisms responsible for photooxidation involve superoxide radical anion and …

Exploring New Synthetic Strategies By Using Novel Manganese Carboxylate Complexes Along With Two Alkoxide Based Ligands, 2-(Hydroxymethyl)-Pyridine And 4,5-Bis(Hydroxymethyl)-2-Methylpyridin-3-Ol In The Area Of Polynuclear Coordination Chemistry, Michael A. Reagan

College of Graduate Studies: Theses & Dissertations

Manganese carboxylate complexes have been well studied in the past, due to their relevance in bioinorganic chemistry and as well as their behavior as nanoscale magnetic materials that is called single-molecule magnets (SMMs). SMMs are special class of magnetic materials in which magnetism is intrinsic to the molecule. Polynuclear manganese clusters often possess high spin ground states as well as large and negative magnetoanisotropy, a combination which leads to an energy barrier for the reversal of the magnetization direction. The paramagnetic nature of manganese at its common oxidation states with an ample number of unpaired electrons often leads to high-nuclearity …

An Interdisciplinary Approach To The Target Elucidation Of Novel Antibiotic 31g12, Larissa A. Walker

Graduate Student Theses, Dissertations, & Professional Papers

Staphylococcus aureus is a Gram-positive bacterial pathogen responsible for nosocomial and community-acquired infections that can quickly acquire antibiotic resistance. We have identified a novel triazole antimicrobial 31G12 based on the natural product core of nonactin isolated from the fermentation of Streptomyces griseus, that is active against many Gram-positive bacteria as well as antibiotic resistant methicillin-resistant S. aureus and vancomycin-resistant Enterococcus. The synthesis and characterization indicate that 31G12 exists as a mixture of two rotamers at room temperature and displays bacteriostatic activity against S. aureus with moderate mammalian cell toxicity. We have currently identified potential protein targets of 31G12 in …

Characterizing Glucose Tolerance In Adult Lew.1wr1 Rats, Luis Mercado, Genoah Collins, Amelia Clopp

Summer Community of Scholars Posters (RCEU and HCR Combined Programs)

No abstract provided.

Presence And Potential Sources Of Pharmaceutical And Personal Care Product Chemicals In Messalonskee Lake, Alyssa T. Kullberg

Honors Theses

Pharmaceuticals and personal care product chemicals (PPCPs) represent a large group of contaminants that are mostly not regulated in surface or drinking water and whose presence and environmental and health impacts are poorly understood. We investigated the presence and potential sources of 18 PPCPs in Messalonskee Lake. We collected samples four times over the summer of 2017 at 13 sites around the lake. Samples were tested for PPCPs using liquid chromatography-tandem mass spectrometry. We detected five out of the 18 PPCPs we tested for at the ng/L level: caffeine, 1,7-dimethylxanthine, acetaminophen, sulfachloropyridazine, and amphetamine. PPCPs showed a significant positive correlation …

Stable Bromine Isotope Signature Of Bromoform From Enzymatic And Abiotic Formation Pathways And Its Application In Identifying Sources Of Environmental Bromoform In The Damariscotta River, Chengyang Wang

Honors Theses

Bromoform is a major source of atmospheric bromine. Most bromoform is produced by marine organisms including macroalgae and phytoplankton, using the enzyme bromoperoxidase (BPO). Bromoform can also be a byproduct of industrial processes such as water disinfection. Identifying sources of environmental bromoform is still a challenge. A novel technique of using quadrupole mass spectrometry coupled to a gas chromatography (GCqMS) was developed and optimized for Br isotope analyses. The study shows that GCqMS in single ion monitoring (SIM) mode can measure 81Br with precision of around ±0.7‰ (60pmol bromoform injected). This study aims to investigate stable Br isotopes of bromoform …

Corrigendum: Composition Of Dissolved Organic Matter In Pore Waters Of Anoxic Marine Sediments Analyzed By 1h Nuclear Magnetic Resonance Spectroscopy, Christina A. Fox, Hussain A. Abdulla, David J. Burdige, James P. Lewicki, Tomoko Komada

OES Faculty Publications

No abstract provided.

Perspectives On Chemical Oceanography In The 21st Century: Participants Of The Come Aboard Meeting Examine Aspects Of The Field In The Context Of 40 Years Of Disco, Andrea J. Fassbender, Hilary I. Palevsky, Todd R. Martz, Anitra E. Ingalls, Martha Gledhill, Sarah E. Fawcett, Jay A. Brandes, Lihini I. Aluwihare, The Participants Of Come Aboard, Disco Xxv

OES Faculty Publications

The questions that chemical oceanographers prioritize over the coming decades, and the methods we use to address these questions, will define our field's contribution to 21st century science. In recognition of this, the U.S. National Science Foundation and National Oceanic and Atmospheric Administration galvanized a community effort (the Chemical Oceanography MEeting: A BOttom-up Approach to Research Directions, or COME ABOARD) to synthesize bottom-up perspectives on selected areas of research in Chemical Oceanography. Representing only a small subset of the community, COME ABOARD participants did not attempt to identify targeted research directions for the field. Instead, we focused on how best …

Interpreting Mosaics Of Ocean Biogeochemistry, Andrea Fassbender, A. Bourbonnais, Sophie Clayton, P. Gaube, M. Ormand, P.J.S. Franks, M. A. Altabet, D.J. Mcgillicuddy Jr.

OES Faculty Publications

Advances in technology and modeling capabilities are driving a surge in progress in our understanding of how ocean ecosystems mix and mingle on medium to small scales.

Synthesis And Cytotoxicity Of Mansonone G Derivatives, Nhung Ngo Thi Tuyet

Chulalongkorn University Theses and Dissertations (Chula ETD)

Mansonone G (N01), a naturally occurring o-naphthoquinone was isolated from the heartwoods of Mansonia gagei Drumm. as the major component. Seventeen ether derivatives N02-N18 were successfully synthesized by the reaction of mansonone G with corresponding alkyl halide. All derivatives were characterized by 1H, 13C NMR and HRMS. Eleven of them were confirmed to be new compounds. The cytotoxic evaluation was performed against A549 and HT-29 cancer cell lines. Interestingly, all candidates displayed more potent cytotoxicity than mansonone G. The hydrophobicity was found as an important contributor to the activity. N08 displayed the most potent cytotoxicity toward the interested cells with …

Glycosylation Of 2-Nitro-1-Thioglycoside As Glycosyl Donor, Panachai Wongsrisupphakul

Chulalongkorn University Theses and Dissertations (Chula ETD)

2-Nitro thioglycosides are versatile building blocks for amino sugar synthesis. Nitro moiety at C2 position acts as stable surrogate for amino group and can be converted at late state of the synthesis. In this work, chemical glycosylation of 2-nitro thioglycoside donors were investigated. 2-nitro thioglycosides were prepared from tri-O-acetyl-D-galactal which underwent functional group manipulations and nitration to obtain 2-nitrogalactal in 47% over 4 steps. Then, Michael additions of 2-nitrogalactal with various type of S-nucleophiles were performed by using NaDTC as activator to produce 2-nitrothioglycoside donors in 46–85% yield. Glycosylation between 2-nitro thioglycoside donors and methyl 2,3,4-tri-O-benzyl-α-D-glucopyranoside as glycosyl acceptor were …

Preparaton Of Selenium Nanoparticles Stabilized By Pullulan And Derivatives, Punnida Nonsuwan

Chulalongkorn University Theses and Dissertations (Chula ETD)

The inorganic/organic selenium nanoparticles (SeNPs)/pullulan derivative hybrid material was obtained using a simple and green strategy. The chemical structure of pullulan, folic acid decorated cationic pullulan (FA-CP) was designed for stabilizing SeNPs. The SeNPs stabilized by FA-CP were observed after the addition of a cysteine hydrochloride solution into the solution mixture of Na2SeO3 and FA-CP. The results suggested that the concentrations of cysteine and stabilizer were the key factors to control the shape and morphology of SeNPs. The spherical SeNP/FA-CP was found in ratio of Na2SeO3 to cysteine was 1:1. It exhibited low toxicity against normal cells while higher toxicity …

Synthesis And Characterization Of Biomimetic Dinuclear And Tetranuclear Copper Complexes, Syed Rahmath Ullah Joy

Masters Theses

Seven new copper(II) complexes were prepared from the condensation reaction of 4-tert-butyl-2,6-diformylphenol with two equivalents of bis(pyrazolyl)ethanamine or 3,5-dimethyl-bis(pyrazolyl)ethanamine moieties in the presence of two equivalents of various copper(II) starting materials having different counter ions (i.e. acetate - AcO^-, perchlorate - CIO₄^-, tetrafluoroborate - BF₄^-, nitrate - NO₃^-, and chloride - Cl^-). The resulting copper(II) complexes were characterized in solid state by single crystal X-ray crystallography, and in solution by UV-Vis and ESI/MS spectroscopies.

X-ray crystallographic studies showed that in solid state two types of …

Pd-Based Photocatalysts For Sonogashira C-C Cross-Coupling Reactions, Komadhie Charuka Dissanayake

Masters Theses

Sonogashira C-C cross-coupling reaction has been heavily used for its simplicity, flexibility and value. Although the original Sonogashira C-C cross coupling reaction conditions entail the use of 0.5 mol% of Pd catalyst, 2 mol% of Cul as co-catalyst at room temperature, the experimental conditions used in laboratories to prepare some compounds vary substantially, especially with respect to the reaction time, temperature and loading amount of the catalysts. The most significant drawback of the conventional Sonogashira reaction is the use of Cul as it leads to the formation of homocoupling product when the reaction is exposed to air or oxidizing agents. …

Biosensing And Catalysis Applications Of Nanoporous Gold (Npg) And Platinum-Speckled Nanoporous Gold (Npg-Pt) Electrodes, Christopher J. Freeman

Theses and Dissertations

The importance of porous materials has risen substantially in the last few decades due to their ability to reduce the size and cost of bioanalytical devices and fuel cells. First, this work aims to describe the fabrication of nanoporous gold (NPG) electrodes that are resistant to electrode passivation due to fibrinogen biofouling in redox solutions. The effect on potentiometric and voltammetric experiments was seen as a deviation from ideal behavior on planar gold electrodes, whereas NPG electrodes were consistently behaving in a Nernstian fashion at low concentrations of ferri-ferrocyanide (£100 mM). An improvement in electrode behavior on NPG electrodes versus …

Synthesis And Characterization Of Magnetic Cabides And Oxides Nanomaterials, Hei Man Tsui

Theses and Dissertations

The design and development of nanoparticles is of great interest in the current energy and electronic industry. However, based on the current materials available the production cost can be high with insignificant magnetic and mechanical properties. Specifically, rare-earth magnetic materials composed of neodymium and samarium are known for their high magnetic performance, however, due to the cost of development there is a need to develop a versatile and cost effective material. Alternatively, cobalt carbide nanomaterials have shown to be a promising alternative for rare-earth free magnets as they exhibit comparable properties as hexaferrite magnetic materials. The primary goal of this …

5-Ht2b Receptor-Mediated Cardiac Valvulopathy, Pallavi Nistala

Theses and Dissertations

5-HT_2B receptor agonism causes cardiac valvulopathy, a condition characterized by thickening of the heart valves and as a result, regurgitation of blood within the heart. The anti-obesity drug fenfluramine, which was originally prescribed as an anorectic, was withdrawn from the market due to causing cardiac valvulopathy. Fenfluramine, after metabolism by N-dealkylation, produces the metabolite norfenfluramine, which acts as a more potent valvulopathogen. The same was seen with MDMA (ecstasy), a popular drug of abuse, which is metabolized by N-dealkylation to produce MDA, a more potent valvulopathogen. Glennon and co-workers. studied a series of 2,5-dimethoxy-4- substituted phenylisopropylamines (DOX type) hallucinogens …

Synthesis And Some Optical Results Of Long Chain Substituted Phthalocyanines, İbrahi̇m Özçeşmeci̇, İdri̇s Sorar

Turkish Journal of Chemistry

Four metallo (zinc, copper, vanadyl, and indium) phthalocyanine derivatives bearing four aliphatic (hexylthio) groups were prepared from corresponding phthalonitrile compounds. The metallophthalocyanines were characterized with ultraviolet–visible spectroscopy (UV-Vis), proton nuclear magnetic resonance (1H NMR), Fourier transform-infrared spectroscopy (FT-IR), and mass and elemental analyses techniques. Aggregation properties of metallophthalocyanines in solution were studied in varied concentration ranges. Thin films of metallophthalocyanines were obtained by spin coating technique. Optical measurements showed that transmittance values of metallophthalocyanine thin films obviously changed with respect to the metal ion in the phthalocyanines. Transmittance spectra of the phthalocyanines synthesized using different metal ions showed a variation …

Facile Synthesis Of Heteroaryl Substituted -Lactams From Nitrovinyl Arenes, Seda Çinar, Canan Ünaleroğlu

Turkish Journal of Chemistry

Aliphatic nitroalkanes with different functional groups were synthesized from the Michael addition reactions of active methylene compounds 2 and nitrovinyl arenes 1 in high yields. The synthesized Michael adducts were subjected to intramolecular cyclization to give heteroaryl substituted γ-lactams in good to high yields under mild reaction conditions.

Organic Modification Of Montmorillonite And Effect Of Catalytic Selectivity On Thedimerization Of Unsaturated Fatty Acid, Xue Huang, Guoqiang Yin, Guangzhu Feng

Turkish Journal of Chemistry

This study describes the selective synthesis of C36-dimer fatty acids, by reacting unsaturated fatty acid at 533 K for 6 h in the presence of montmorillonite and lithium chloride as the catalyst and cocatalyst, respectively. The catalytic performance of different montmorillonite and organic modified montmorillonite catalysts was investigated in the dimerization of technical grade unsaturated fatty acid, and the influence of the catalyst structure and composition on the catalytic performance was analyzed. All the samples were characterized by X-ray diffraction (XRD), Fourier transform-infrared spectroscopy (FT-IR), scanning electron microscope (SEM), transmission electron microscopy (TEM), thermogravimetry (TG), and dispersion experiments. The results …

Synthesis Of Benzaldehyde By Swern Oxidation Of Benzyl Alcohol In A Continuous Flow Microreactor System, Lin Zhu, Xiaohui Xu, Fuping Zheng

Turkish Journal of Chemistry

Preparation of benzaldehyde by Swern oxidation of benzyl alcohol was carried out in a continuous flow microreactor system. Dimethyl sulfoxide (Me2SO) was used as oxidizing agent and oxalyl chloride or p-toluenesulfonyl (p-TsCl) chloride was used as the activating agent. Benzyl alcohol was oxidized to benzaldehyde by the Me2SO-activating agent mixture in the continuous flow microreactor system. The optimized reaction conditions of the Swern oxidation were as follows: oxalyl chloride was used as the activating agent; the mole ratio of Me2SO, oxalyl chloride, and benzyl alcohol was 4:2:1; the ow rate of Me2SO was 1.5 mL/min; the reaction temperature was 15 …

Adsorption Of Anionic And Cationic Dyes On Biochars, Produced By Hydrothermalcarbonization Of Waste Biomass: Effect Of Surface Functionalization And Ionicstrength, Ezgi̇ Çağlar, Yusuf Osman Donar, Ali̇ Sinağ, İbrahi̇m Bi̇roğul, Selva Bi̇lge, Kivanç Aydincak, Oleksii Pliekhov

Turkish Journal of Chemistry

In this work, surface-functionalization agents and various salts as auxiliaries were used to improve the adsorption capacity of biochars produced via hydrothermal carbonization of glucose, cellulose, and hazelnut shell. The effect of surface functionalization with different acids and bases as well as neutral salts on the adsorption of methylene blue and methyl orange was investigated using Boehm titration, Fourier transform infrared spectroscopy, and X-ray photoelectron spectroscopy techniques. Surface functionalization of biochars leads to an increase in the number of oxygen-containing functional groups on the surface, thus increasing the adsorption capacity. To probe the influence of ionic strength on the adsorption …

Physicochemical Characterization Of A Polymeric Conductor: Application To Defluoridation Of Industrial Effluent By Electrodialysis, Maroua Arfaoui, Ali Ouejhani, Bechir Hamrouni

Turkish Journal of Chemistry

In many places around the world, the uoride concentration in ground water as raw water is higher than the threshold standard for healthy drinking water. The aim of this work is to study the characteristics of an anionic membrane that will be the subject of an application for de uoridation by electrodialysis. The first objective of this work is to evaluate the physicochemical characteristics of the membrane used in experiments by determination of the exchange capacity, water uptake, ionic conductivity, and transport number (Hittorf method). The second part consists of studying the effect of different parameters such as electrodialysis time, …

Kinetics Of Silver(I)-Catalyzed Oxidation Of Allyl Alcohol By Peroxodiphosphate Inacetate Buffers, Priyamvada Sharma, Riya Sailani, Deepmala Pareek, Chandra Lata Khandelwal

Turkish Journal of Chemistry

The kinetics and mechanism of silver(I)-catalyzed oxidation of allyl alcohol with peroxodiphosphate in acetate buffers have been studied. The rate is independent of allyl alcohol concentration. The effect of other reaction parameters such as hydrogen and acetate ions has also been studied. The rate law accounting for all experimental observations corresponds to the proposed mechanism. The energy and entropy of activation have also been evaluated by employing Eyring plots.

Cu(Ii) Immobilized On Fe$_{3}$O$_{4}$ @Agarose Nanomagnetic Catalyst Functionalizedwith Ethanolamine Phosphate-Salicylaldehyde Schiff Base: A Magnetically Reusablenanocatalyst For Preparation Of 2-Substituted Imidazolines, Oxazolines, Andthiazolines, Zeinab Zarei, Batool Akhlaghinia

Turkish Journal of Chemistry

Herein we synthesized Cu(II) immobilized on Fe$_{3}$O$_{4}$ @Agarose functionalized with ethanolamine phosphate{ salicylaldehyde Schiff base (Fe$_{3}$O$_{4}$ @Agarose/SAEPH$_{2}$ /Cu(II)) as a new and cost-effective nanomagnetic catalyst. The nanomagnetic catalyst was characterized by FT-IR, XRD, VSM, SEM-EDX, TEM, TGA, and ICP techniques and it was found that the particles were about 9-25 nm in size and spherical with entrapment of the Fe$_{3}$O$_{4}$ particles in the hollow pore structure of the agarose. The prepared nanomagnetic catalyst showed excellent activity for preparation of 2-substituted imidazolines, oxazolines, and thiazolines. The catalyst is easy to prepare and exhibits higher catalytic activity than some commercially available copper …

Nanocapsulation Of Herbicide Haloxyfop-R-Methyl In Poly(Methyl Methacrylate):Phytotoxicological Effects Of Pure Herbicide And Its Nanocapsulated Form Onduckweed As A Model Macrophyte, Samaneh Torbati, Mehdi Mahmoudian, Neda Alimirzaei

Turkish Journal of Chemistry

In the present study the nanocapsulation of Haloxyfop-R-methyl in poly(methyl methacrylate) was success- fully performed. Poly(methyl methacrylate)/Haloxyfop-R-methyl nanocapsules were synthesized using a miniemulsion method and their surface morphology was studied by scanning electron microscopy and transition electron microscopy. The chemical characterization of nanocapsules was done by FT-IR spectroscopy. The herbicide loading and encap- sulation efficiency were also analyzed for the herbicide-loaded nanocapsules. In order to evaluate the toxic effects of nanocapsulated herbicide and pure herbicide on Lemna minor L., some physiological effects of these two compounds were investigated. The plant growth rate, photosynthetic pigment contents, and activities of antioxidant enzymes …

Sodium Borohydride For The Near-Future Energy: A ''Rough Diamond'' For Turkey, Ümi̇t Bi̇lge Demi̇rci̇

Turkish Journal of Chemistry

Boron-based materials are potential solutions in the field of energy. They have been regarded as hydrogen storage materials, liquid fuels of direct liquid-fed fuel cells (DLFCs), electrolytes of battery, and/or energetic substances. A typical example is sodium borohydride (NaBH$_{4}$. In sodium hydroxide-stabilized aqueous solutions, it is seen as an efficient H$_{2}$ generator or a performing fuel of DLFCs. Actually, it plays a wider role; it is also the precursor of several boron-based materials of interest in the field of energy. In other words, it is indirectly considered for other energy applications, i.e. solid electrolytes of all solid-state batteries and hypergolic …