Chemistry Commons^™

Effect Of Various Substituents On Intramolecular 1,1-Vinylboration, Synthesis Of 1-Silacyclobutene Derivatives, Ezzat Khan, Bernd Wrackmeyer

Turkish Journal of Chemistry

The reaction of 1-boryl-1-alkenyl chlorosilane derivatives with alkynyllithium reagents [Li-C\equiv C-R^3 (R^3~=~Ph, SiMe_3)] at low temperature (--78 °C) affords alkenyl(alkyn-1-yl)silanes. These compounds are precursors of 1-silacyclobutene derivatives, which are formed via intramolecular 1,1-vinylboration. This reaction works for various groups at silicon (R^1/R^2: R^1 = H, Me, Ph; R^2 = Me, Ph) and at the C=C and C\equiv C units (R/R^3: R = ^nBu, Ph; R^3 = ^nBu, Ph, SiMe_3). The conversion into 1-silacyclobutene derivatives is incomplete only in the case of R^3 = SiMe_3. The reactions were monitored by NMR spectroscopy in order to elucidate the reaction mechanism, and the …

Solid Phase Extraction Of Copper, Nickel, And Cobalt In Water Samples After Extraction Using Surfactant Coated Alumina Modified With Indane-1,2,3-Trione 1,2-Dioxime And Determination By Flame Atomic Absorption Spectrometry, Mahdi Hosseini, Nasser Dalali, Ali Karimi, Kourosh Dastanra

Turkish Journal of Chemistry

A simple method for simultaneous pre-concentration of Cu, Ni, and Co metal ions prior to their determination by flame atomic absorption spectrometry is reported. The method is based on the extraction of target ions via complexation with indane-1,2,3-trione 1,2-dioxime immobilized on sodium dodecyl sulfate (SDS) coated alumina. The metal content on the adsorbent was eluted with 4.5 mL of 2 mol L^{-1} nitric acid. The influences of the analytical parameters including pH, sample volume and flow rate, and eluent type and flow rate were investigated. The effect of matrix ions on the retentions of the analytes was also examined. The …

Electrochemical Impedance Spectroscopic Studies Of The Passive Layer On The Surface Of Copper As A Function Of Potential, Amtul Naseer, Athar Khan

Turkish Journal of Chemistry

Electrochemical impedance spectroscopy (EIS) and cyclic voltammetry (CV) were used to investigate the oxide layer formed on a copper disc electrode and the changes that took place when treated potentiostatically in the range of -0.3 V to 0.9 V in buffer of pH 8.5. The response of an electrode using EIS, initially at equilibrium, to an applied potential was then modeled with equivalent circuits, proposed for different potential regions that completely illustrated the Cu/oxide/electrolyte systems and their properties in terms of 2 interfaces. Criterion for the applicability of equivalent circuit models was discussed. Changes in the film/metal interface as a …

Chemical Composition And Antimicrobial Activity Of The Essential Oils Of Mosses (Tortula Muralis Hedw., Homalothecium Lutescens (Hedw.) H. Rob., Hypnum Cupressiforme Hedw., And Pohlia Nutans (Hedw.) Lindb.) From Turkey, Osman Üçüncü, Tayyi̇be Beyza Cansu, Turan Özdemi̇r, Şengül Alpay Karaoğlu, Nuretti̇n Yayli

Turkish Journal of Chemistry

The essential oils of mosses [Tortula muralis Hedw. (Pottiaceae), Homalothecium lutescens (Hedw.) H. Rob. (Brachytheciaceae), Hypnum cupressiforme Hedw. (Hypnaceae), and Pohlia nutans (Hedw.) Lindb. (Mniaceae)] were investigated by means of GC-FID/MS techniques. The major components were nonanal (18.3%) and tetradecanol (4.3%) in the oil of T. muralis, nonanal (36.8%) and tricosane (6.5%) in the oil of H. lutescens, nonanal (12.5%) and 2E-tetradecen-1-ol (6.9%) in the oil of H. cupressiforme, and nonanal (7.8%) and 2E-tetradecen-1-ol (7.1%) in the oil of P. nutans. The essential oils of T. muralis, H. lutescens, H. cupressiforme, and P. nutans were rich as in non-terpenoid components …

Synthesis And Antimicrobial Activities Of Some New 1,2,4-Triazole Derivatives, Nesli̇han Demi̇rbaş, Ahmet Demi̇rbaş, Hacer Bayrak, Hakan Bektaş, Şengül Alpay Karaoğlu

Turkish Journal of Chemistry

The synthesis of ethyl [3-(cyanomethyl)-5-alkyl-4H-1,2,4-triazol- 4-yl]carbamates (2a-d) was performed starting from ethyl 2-[ethoxy(4- (aryl)methylene]hydrazinecarboxylates (1a, 1b). The treatment of 2a with thiosemicarbazide afforded ethyl [3-[(5-amino-1,3,4-thiadiazol- 2-yl)methyl]-5-(4-nitrophenyl)-4H-1,2,4-triazol-4-yl]carbamates (3a), whereas compound 2b produced 5-{[4-amino-5-(4-methylphenyl)- 4H-1,2,4-triazol-3-yl]methyl}-1,3,4-thiadiazol-2-amine (3b) in the same reaction conditions. The treatment of tert-butyl 2-[2-(4-chlorophenyl)-1-ethoxyethylidene]hydrazinecarboxylate (5) with malonohydrazide or cyanoacethydrazide gave the corresponding 1,2,4-triazol-ylcarbamate derivatives (6 or 9); then the hydrolysis of these compounds resulted in the formation of 3-{[4-amino-5-(4- chlorobenzyl)-4H-1,2,4-triazol-3-yl]methyl}-5-(4-chlorobenzyl)-4H- 1,2,4-triazol-4-amine (7) and [4-amino-5-(4-chlorobenzyl)-4H- 1,2,4-triazole-3-yl]acetonitrile (10), respectively. The synthesis of the Schiff base derivatives 3-(4-chlorobenzyl)-5-{[5-(4-chloroben- zyl)-4-[(2-hydroxyphenyl-methylene)amino]-4H-1,2,4-triazol-3-yl]methyl} -N-(2-hydroxyphenylmethylene)-4H-1,2,4-triazol-4-amine (8), and (5-(4-chlorobenzyl)-4-{[(2,6-dichlorophenyl)methylene]amino}-4H-1,2,4- triazol-3-yl)acetonitrile (12) was performed from the reaction of compounds 7 …

Ethyl 5-Oxo-3-Arylamino-2,5-Dihydroisoxazole-4- Carboxylates As Sources Of Imidazopyrimidine And Aminoindole Derivatives, Ahmad Poursattar Marjani, Jabbar Khalafy

Turkish Journal of Chemistry

The reaction of ethyl 5-oxo-3-arylamino-2,5-dihydroisoxazole-4- carboxylates with 2-chloropyrimidine and 2-chlorobenzoxazole gave the corresponding isoxazolones with pyrimidine and benzoxazole rings substituted on N-2. Their rearrangements with triethylamine in ethanol produced the corresponding imidazopyrimidine and aminoindole derivatives, respectively, through intramolecular cyclisation.

Reactions Of 4-Benzoyl-1,5-Diphenyl-1h-Pyrazole-3- Carboxylic Acid Chloride With Various Hydroxylamines And Carbazates, Eli̇f Korkusuz, İsmai̇l Yildirim

Turkish Journal of Chemistry

The 1H-pyrazole-3-carboxylic acid 2 was converted via reactions of its acid chloride 3 with various hydroxylamine 4a-f and carbazate derivatives 8a-c into the corresponding novel N-substituted-4-benzoyl-1,5-dipenyl-1H-pyrazole-3-carboxamides 5a-c, N,N-disubstituted-4-benzoyl-1,5-diphenyl-1H-pyrazole-3-carboxylates 6d,e, 4-benzoyl-N-{[(4-benzoyl-1,5-diphenyl-1H-pyrazol-3-yl)carbonyl]oxy}- N-methyl-1,5dip- henyl-1H-pyrazole-3-carboxamide (7), and 4-benzoyl-N'-(alkoxycarbonyl)-1,5-diphenyl-1H-pyrazole-3-car- bohydrazides 9a,b and 10, respectively, in good yields (65\%-90\%). The reactions of 3 with 4 and 8 in xylene for 8-15 h with catalytic amounts of base led to the formation of the products 5-7, 9, and 10. The structures of all new synthesized compounds were established by the ^{13}C-NMR, ^1H-NMR, IR spectroscopic data, and elemental analyses.

An Efficient And Green Approach For The Synthesis Of Vinyl Aryl Ethers In The Presence Of Guanidine Hydrochloride, Seyed Mohammad Vahdat, Robabeh Baharfar

Turkish Journal of Chemistry

A stereoselective procedure for vinyl aryl ether bond formation by direct coupling of dialkyl acetylenedicarboxylates and substituted phenols or naphthols under mild reaction conditions has been developed. Using guanidine hydrochloride as a new catalyst and water-acetone as green solvent, dialkyl acetylenedicarboxylates were reacted with substituted phenols or naphthols in room temperature to produce vinyl aryl ethers in good to excellent yields.

Vapor Phase Alkylation Of Toluene Using Various Alcohols Over H3po4/Mcm-41 Catalyst: Influence Of Reaction Parameters On Vapor Phase Alkylation Of Toluene Using Various Alcohols Over H_3po_4/Mcm-41 Catalyst: Influence Of Reaction Parameters On Selectivity And Conversion, Alireza Abbaspourrad, Roozbeh Javadkalbasi, Farzad Zamani

Turkish Journal of Chemistry

A mesoporous MCM-41 molecular sieve material with a molar ratio of SiO_2/Al_2O_3 = 70 and loaded with H_3PO_4 was used as a catalyst for the alkylation of toluene, using various alcohols, namely methanol, iso-propanol, and tert-butanol, as alkylating agents. Para-alkylated toluene was the predominant product, formation of which was enhanced by moderate temperature, low amounts of the alkylating agents in the feed, and high carrier gas flow rate. Time on stream was found to exert a profound effect on the selectivity and conversion to the different products.

Synthesis And Surfactant Properties Of N-Acylation Compounds Derived From Hydrolysis Degradation Products Of N-(\Beta-Cianoethyl)-\Epsilon-Caprolactam, Andreea Bondarev

Turkish Journal of Chemistry

N-acyl amino acids can be used as active surface agents in the detergents industry, as well as in the pharmaceutical industry and cosmetics. Properties of these compounds are superior to those of fatty acids soaps and they are not toxic to the environment and have low Kraft points, because of peptide bonds (CO-NH). Acylation at the nitrogen atom can be performed with good yields without catalysts, for strong nucleophilic derivatives. The synthesis of some derivatives of 4-azasebacic acid, which are hydrolysis degradation products from N-(\beta -cianoethyl)-\epsilon -caprolactam, has been described and the N-acylation processes for these compounds are also presented. …

Determination Of Trace Element Contents Of Thymus Species From Turkey, Fatümetüzzehra Küçükbay, Ebru Kuyumcu

Turkish Journal of Chemistry

Eleven mineral and trace elements (Mg, Ca, K, Fe, Mn, Al, Zn, Cu, Cd, Ni, and Pb) were determined in the Thymus species growing in Turkey. The total concentrations were measured in samples mineralized with concentrated nitric acid and hydrogen peroxide in a microwave system. The determination of mineral and trace elements in the leaves of the Thymus species was carried out by flame and graphite furnace atomic absorption spectrometry. The accuracy of the method was ensured by using standard reference material (NIST-SRM 1515 apple leaves). The concentration of elements in the Thymus species and their biological activity on humans …

Determination Of Ceftriaxone, Ceftizoxime, Paracetamol, And Diclofenac Sodium By Capillary Zone Electrophoresis In Pharmaceutical Formulations And In Human Blood Serum, Amber Solangi, Saima Memon, Arfana Mallah, Najma Memon, Muhammad Yar Khuhawar, Muhammad Iqbal Bhanger

Turkish Journal of Chemistry

A simple and fairly fast capillary zone electrophoresis method has been developed for the determination and separation of ceftriaxone, ceftizoxime, paracetamol, and diclofenac sodium in a mixture, in pharmaceutical formulations, and in blood serum. A 50 mM sodium tetraborate background electrolyte solution (pH 9.0) was found to be suitable for separation of all the drugs. An uncoated fused-silica capillary of a total length of 57 cm (effective length 50 cm) was used for separation. All the analytes were completely separated within 8.0 min at an applied voltage of 30 kV and detection was performed at 214 nm .Validation of the …

Synthesis And Characterization Of Ba/Mcm-41, Emi̇ne Kaya, Nuray Oktar, Gürkan Karakaş, Kirali̇ Mürtezaoğlu

Turkish Journal of Chemistry

Mesoporous Ba/MCM-41 type materials (Ba/MCM-41) with high Ba/Si molar ratios between 0.025 and 0.1 were synthesized by direct hydrothermal synthesis. The samples were characterized by XRD, nitrogen adsorption, TGA-DTA, FTIR, SEM-EDS, and TEM techniques. BET surface areas of samples with various Ba loadings were found between 722 and 931 m^2/g with 28 Å average pore size, which is consistent with the pore size of 30 Å for pure MCM-41 samples synthesized by the same procedure. The crystal structures of synthesized MCM-41 and Ba/MCM-41 were confirmed by XRD analysis. Among the investigated Ba/MCM-41 samples, the formation of barium oxide and barium …

Computational Study On Nitronium Squarate - Potential Oxidizers For Solid Rocket Propulsion?, Eli̇f Gökçinar, Thomas Klapötke

Turkish Journal of Chemistry

The enthalpies of formation for solid ionic nitronium squarate, [NO_2]_2[C_4O_4], and covalent squaric acid dinitrate ester, O_2N-C_4O_4-NO_2, were calculated using the complete basis set (CBS-4M) method of Petersson and coworkers in order to obtain very accurate energies. The covalent form (O_2N-C_4O_4-NO_2) was identified as the more stable isomer. The combustion parameters with respect to possible use as ingredients in solid rocket motors for both stable species were calculated using the EXPLO5 code. The performance of an aluminized formulation with covalently bound dinitrate ester (O_2N-C_4O_4-NO_2) was shown to be comparable to that of ammonium perchlorate/aluminum. This makes squaric acid dinitrate ester …

Comparative Essential Oil Analysis Of Geranium Sylvaticum Extracted By Hydrodistillation And Microwave Distillation, Nuran Kahri̇man, Gonca Tosun, Hasan Genç, Nuretti̇n Yayli

Turkish Journal of Chemistry

The essential oil of Geranium sylvaticum L. (Geraniaceae) was isolated by hydrodistillation (HD) and microwave distillation (MD). The composition of the volatile oils was characterized by GC-FID and GC-MS. A total of 73 and 70 compounds were identified, constituting over 90.3% and 98.7% of oil composition of G. sylvaticum, respectively. Sesquiterpene hydrocarbons were shown to be the main group of constituents (HD: 31.7% and MD: 39.8%). The major component of the oils of G. sylvaticum was \gamma -muurolene (HD: 10.9% and MD: 19.6%). The comparative study showed that the amount of total volatiles (98.7%) and the major constituent (39.8%) were …

Quantum Chemical Studies On Tautomerism And Basicity Behavior Of Some 1,2,4-Triazole Derivatives, Cemi̇l Öğreti̇r, Yadi̇gar Gülseven Sidir, İsa Sidir, Erol Taşal

Turkish Journal of Chemistry

The acidity constants, relative stabilities, and tautomeric equilibrium constants of some 1,2,4-triazole derivatives were determined using the density functional theory (DFT) with the B3LYP method and 6-311G(d,p) basis set. The integral equation formalism version of the polarizable continuum model (IEFPCM) was used in the calculations of the aqueous phase. The calculated tautomeric equilibrium and relative stabilities values revealed that the 4H-1,2,4 triazole form for all studied molecules was favored over the 1H-1,2,4 triazole form. Protonation processes indicated the predominance of the 1H-1,2,4 triazole form over the 2H-1,2,4 triazole form. The correlation attempt between the experimental and the calculated acidity constants, …

Synthesis, Characterization And Development Of Catalysts For Co2 Capture, Anitha Suhas Wishrojwar

University of Kentucky Master's Theses

Fossil fuel and advanced industrialization techniques contribute to global warming through emissions of greenhouse gases such as CO₂. In order to mitigate climate change, there is a desperate need to reduce CO₂ emissions from different sources. CO₂ capture and sequestration (CCS) play an important role in these reductions.

Naturally occurring enzymes, e.g., carbonic anhydrase (CA), can catalyze these reactions in living systems. Much effort has been focused on complexes of zinc with ligands such as teta, cyclen and tripodal ligands including BIMA and Trispyrazolylborates. These complexes have many interesting CO₂ capture properties, but maintain toxic …

Amino Acid Transport In Thermophiles: Characterization Of An Arginine-Binding Protein In Thermotoga Maritima, Matthew S. Luchansky, Bryan S. Der, Sabato D'Auria, Gabriella Pocsfalvi, Luisa Iozzion, Daniela Marasco, Jonathan D. Dattelbaum

Chemistry Faculty Publications

Members of the periplasmic binding protein superfamily are involved in the selective passage of ligands through bacterial cell membranes. The hyperthermophilic eubacterium Thermotoga maritima was found to encode a highly stable and specific periplasmic arginine-binding protein (TM0593). Following signal sequence removal and overexpression in Escherichia coli, TM0593 was purified by thermoprecipitation and affinity chromatography. The ultra-stable protein with a monomeric molecular weight of 27.7 kDa was found to exist as both a homodimer and homotrimer at appreciable concentrations even under strongly denaturing conditions, with an estimated transition temperature of 116 °C. Its multimeric structure may provide further evidence of …

Amino Acid Transport In Thermophiles: Characterization Of An Arginine-Binding Protein In Thermotoga Maritima. 2. Molecular Organization And Structural Stability, Andrea Scirè, Anna Marabotti, Maria Staiano, Luisa Iozzion, Matthew S. Luchansky, Bryan S. Der, Jonathan D. Dattelbaum, Fabio Tanfani, Sabato D'Auria

Chemistry Faculty Publications

ABC transport systems provide selective passage of metabolites across cell membranes and typically require the presence of a soluble binding protein with high specificity to a specific ligand. In addition to their primary role in nutrient gathering, the binding proteins associated with bacterial transport systems have been studied for their potential to serve as design scaffolds for the development of fluorescent protein biosensors. In this work, we used Fourier transform infrared spectroscopy and molecular dynamics simulations to investigate the physicochemical properties of a hyperthermophilic binding protein from Thermotoga maritima. We demonstrated preferential binding for the polar amino acid arginine …

Tuning Σ-Holes: Charge Redistribution In The Heavy (Group 14) Analogues Of Simple And Mixed Halomethanes Can Impose Strong Propensities For Halogen Bonding, Kelling J. Donald, Bernard K. Wittmaack, Chad Crigger

Chemistry Faculty Publications

Halogen bonding between halide sites (in substituted organic molecules or inorganic halides) and Lewis bases is a rapidly progressing area of exploration. Investigations of this phenomenon have improved our understanding of weak intermolecular interactions and suggested new possibilities in supramolecular chemistry and crystal engineering. The capacity for halogen bonding is investigated at the MP2(full) level of theory for 100 compounds, including all 80 MH₄-_nX_n systems (M = C, Si, Ge, Sn, and Pb; X = F, Cl, Br, and I). The charge redistribution in these molecules and the (in)stability of the σ-hole at X as …

Shorter Still: Compressing C-C Single Bonds, Gerarso Martinez-Guajardo, Kelling J. Donald, Bernard K. Wittmaack, Miguel Angel Vazquez, Gabriel Merino

Chemistry Faculty Publications

How short can a C-C single bond get? The bonding in a set of molecules that are related structurally to previously synthesized or theoretically examined systems with short C-C bonds is investigated. According to calculations, a single C-C bond could be compressed to 1.313 A! To the best of our knowledge, this is the shortest single C-C bond reported to date. This shortening is a consequence of a change in the C-C-C bond angle, θ, to minimize strain in the cages and an effort to offset the tension in the surrounding bridges.

Haart Drugs Induce Oxidative Stress And Mitochondrial Dysfunction In Blood-Brain Barrier, Kalyan Reddy Manda

Doctoral Dissertations

"The era of highly active antiretroviral therapy (HAART) has controlled AIDS and its related disorders considerably; however, the prevalence of HIV-1-associated neurocognitive disorders (HAND) has been on the rise in the post-HAART era. In view of these developments, we investigated whether a HAART drug combination of 3'-Azido-2', 3'-deoxythymidine (AZT) and Indinavir (IDV) can alter the functionality of the blood-brain barrier (BBB) endothelial cells, thereby exacerbating the condition. Viability of hCMEC/D3 cells (in vitro model of BBB) that were exposed to the drugs was significantly reduced after a 72 hr treatment, in a dose-dependent manner. Reactive oxygen species (ROS) were highly …

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 …

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 …

Assimilative Domain Proficiency And Performance In Chemistry Coursework, Scott William Byrnes

Walden Dissertations and Doctoral Studies

The assimilation and synthesis of knowledge is essential for students to be successful in chemistry, yet not all students synthesize knowledge as intended. The study used the Learning Preference Checklist to classify students into one of three learning modalities -- visual, auditory, or kinesthetic (VAK). It also used the Kolb Learning Style Inventory (KLSI), which utilizes four learning domains - Converging, Accommodating, Diverging, and Assimilating - to explain the students' maturation process by showing shift from any domain towards the Assimilating domain. A shift approaching this domain was considered as improvement in the assimilation and synthesis of knowledge. This pre-experimental …

Development Of Novel Ahr Antagonists, Hyosung Lee

University of Kentucky Doctoral Dissertations

Aryl hydrocarbon receptor (AHR) is a sensor protein, activated by aromatic chemical species for transcriptionally regulating xenobiotic metabolizing enzymes. AHR is also known to be involved in a variety of pathogenesis such as cancer, diabetes mellitus, cirrhosis, asthma, etc. The AHR signaling induced by xenobiotics has been intensively studied whereas its physiological role in the absence of xenobiotics is poorly understood. Despite a number of ligands of AHR have been reported thus far, further applications are still hampered by the lack of specificity and/or the partially agonistic activity. Thus, a pure AHR antagonist is needed for deciphering the AHR cryptic …

S-Nitrosothiols: Formation, Decomposition, Reactivity And Possible Physiological Effects, Moshood Kayode Morakinyo

Dissertations and Theses

Three biologically-active aminothiols cysteamine (CA), DL-cysteine (CYSH) and DL-homocysteine, were studied in this thesis. These aminothiols react with nitrous acid (HNO₂), prepared in situ, to produce S-nitrosothiols (RSNOs): S-nitrosocyteamine (CANO), S-nitrosocysteine (CYSNO) and S-nitrosohomocysteine (HCYSNO). They also react with S-nitrosoglutathione (GSNO) and S-nitroso-N-acetylpenicillamine (SNAP) through a transnitrosation reaction to produce their corresponding RSNOs. A detailed kinetics and mechanistic study on the formation of these RSNOs and their subsequent decomposition to release nitric oxide (NO) were studied.

For all three aminothiols the stoichiometry of their reaction with nitrous acid is strictly 1:1 with the formation of one mole …

Using Soil-Borne Polycyclic Aromatic Hydrocarbons (Pahs) And Organic Carbon In Soil For Projecting Pollution States Of Pahs In Ambient Air, Chika Yamaguchi

Open Access Theses & Dissertations

Polycyclic Aromatic Hydrocarbons (PAHs) are of environmental concern due to their ubiquitous nature, long-range transport, long half-lives, and toxicity. PAHs enter the environment as a consequence of incomplete combustion and cause adverse health effects. Because they are omnipresent pollutants, PAH distribution is not only a local issue, but also a global issue. Therefore, monitoring PAHs in ambient air and identifying their sources and distribution patterns have tremendous importance in assessing public health. However, sampling and analyzing airborne PAHs with conventional methods is time consuming and costly. In addition, an active sampling method remains unfeasible in many cases because it requires …

Synthesis And Conjugation Of Terminal Α-Galactose Containing, Roger Allan Ashmus

Open Access Theses & Dissertations

Over 16 million people in Latin America are infected with the protozoan parasite Trypanosoma cruzi (T. cruzi), the causative agent of Chagas disease, and up to 50,000 infected people die annually due to complications during the chronic stage of the disease. To date, there are no vaccines or effective drugs to treat chronic Chagas disease. It is known that T. cruzi contains cell surface mucin-like glycoproteins with terminal α-galactosyl residues, and it is well established that they are highly immunogenic. The exact structure of the immunogenic carbohydrate epitopes, however, remains unknown. To determine which epitopes have the ability to interact …

Oxidation Of Dibenzothiophene To Dibenzothiophene Using Metal Nanoparticles Supported On Silica, Karina Castillo

Open Access Theses & Dissertations

Silica and nanoparticles of Pt, Au, and Ag supported on silica were tested for the ability to oxidize dibenzothiophene (DBT) to sulfone. High performance liquid chromatography was used to study the removal of DBT from solution. In addition, X- ray diffraction, infrared spectroscopy and Raman Spectroscopy were used to characterize the product of the oxidation reaction. Further studies involved the use X-ray absorption spectroscopy to characterize the nanoparticle catalysts before and after the oxidation reaction.

To better understand the reaction, silica was synthesized at different pHs using three different acids. The acids used to synthesize the silica were HCl, HNO3, …