Chemistry Commons^™

Identification Of Aromatic Acids As Microbial Metabolites Of Fossil-Fuel Compounds Present In Aquifer Systems, Daniel Michael Tomczak

Masters Theses

The identification and quantitation of aromatic acids as transformation products present in contaminated aquifer systems was studied from selected sites. These acids are formed as microbial metabolites in the oxidative degradation of aromatic compounds. The microbial activity in the subsurface can be coupled to the oxidation of the aromatic compounds and the reduction of specific inorganic indicators. Inorganic indicators identified from the sample sites include the reduced forms of iron, nitrate, sulfate, and dissolved oxygen.

The highest concentrations of the aromatic acids were found in the plumes of the contaminated sites. These concentrations also correlated with specific changes in concentrations …

Studies Of Silica As A Polymer Support For Regioselective Reactions On Sucrose, Lei Cheng

Masters Theses

Sucrose is a material that has potential for replacing oil as an industrial feedstock, at least in some instances. A major difficulty in utilizing sucrose is the lack of regioselectivity in its reactions due to the many reactive sites on the sucrose molecule.

This research is part of an attempt to study the technique of molecular recognition in an effort to increase reaction regioselectivity. Molecular recognition by template imprinting should be a way to create a material that would "recognize" and bind to sucrose in such a way as to block certain of the hydroxyl groups on the sucrose. The …

Studies Directed Toward The Synthesis Of Germacranolides Via [2+2] Cycloaddition Followed By Ring Expansion/Elimination Of Β-Lactones, Bryan E. Yates

Masters Theses

Exposure of α-trimethylsilyl β-lactones to magnesium bromide or boron trifluoride etherate in diethyl ether solvent resulted in the smooth generation of β,γ-unsaturated acid derivatives in good yield and isomeric purity. It is believed that this reaction occurs via the formation of a stable tertiary carbocation at the γ-carbon resulting from cleavage of the carbon-oxygen sigma bond due to the complexation of the Lewis acid with the ring oxygen atom. Rapid loss of an adjacent electrofuge then furnishes the unsaturated acids. The β-lactone precursors were prepared by a [2+2] cycloaddition of an aldehyde and an alkyl trimethylsilyl ketene. This method was …

The Synthesis And Characterization Of Ruii(Bpy){(Bpyrm)Ruii(Nh3)4}2](Pf6)6 And [Ruii(Bpy)2(Bpyrm)Ruii(Nh3)4](Pf6)4, Rick Anthony Pavinato

Masters Theses

This thesis describes the synthesis of a trimetallic Ru^II complex [Ru^II(bpy){(bpyrm)Ru^II(NH₃)₄}₂](PF₆)₆ and its bimetallic analog [Ru^II(bpy)₂(bpyrm)Ru^II(NH₃)₄](PF₆)₄. The trimetallic species was designed to be the first in a series of complexes where the reduction potential of the "bridging" complex could be varied (relative to the "terminal" sites) through systematic variation in the metal (M) and/or ligand (LL) … Generation of the [Ru^II-M^II-Ru^III] "mixed-valence" complex would then allow …

Carbonyl Homologation Via Α-Trimethylsilyl Β-Lactone Rearrangement: A Nonbasic Wittig Alternative, Yong Zhang

Masters Theses

Our research group has been interested in β-lactones as useful synthetic intermediates. Transformations of β-lactones, generally ring expansion/opening processes initiated by Lewis acids via ionization/cation-rearrangement or elimination mechanisms, provide efficient protocols for the syntheses of biologically important butyrolactones, β,γ-unsaturated carboxylic acids, or butenolides.

α-Trimethylsilyl β-lactones, synthesized via the BF₃- catalyzed [2+2] cycloaddition of trimethylsilylketene to carbonyl compounds, spontaneously undergo ionization and trimethylsilyl group migration to form α,β-unsaturated trimethylsilyl esters. The trimethylsilyl moiety facilitates the ionization process because of its β-cation stabilizing ability. The two-carbon homologated α,β-unsaturated acids are formed in yields from moderate to high (41-99%) upon aqueous …

Kinetic And Chemical Modification Studies On Malate Dehydrogenase From E. Coli, Fang Jenny Zhao

Masters Theses

Malate dehydrogenase (MDH) is the enzyme which catalyzes the conversion of malate to oxaloacetate in the TCA cycle. The object of this research was to discipher the mechanism of the reaction and the function of the enzyme. MDH from E. Coli was purified and analyzed by chemical modification studies using diethylpyrocarbonate. Results indicate the existence of a histidine residue at the active site necessary for catalysis. From kinetic studies, a group required for catalysis with a pK_a of 8.5 was observed, which we believe to be a histidine residue. These studies indicate that MDH from E. Coli has a …

Macroporous Polymer Synthesis And Characterization: The Role Of Molecular Recognition In The Regioselectivity Of Sucrose Reactions, Gilbert Joshua Matare

Masters Theses

Molecular recognition has recently emerged as a unique technique for making synthetic polymers with selective binding cavities which can stereoselectively and regioselectively bind to a template molecule in a fashion similar to natural enzymes and antibodies. Its industrial applications in chemistry and biomedicine have been recently exploited. Typical examples include the resolution of amino acids, enantio-separation of racemates and bioactive molecules, selective binding of metal ions and in HPLC investigations. Our research is focused on applying molecular recognition studies to improve the regioselectivity of sucrose reactions.

Sucrose is an abundant industrial raw material of immense industrial importance however, its full …

Separation Of Copper And Iron In Natural Waters By Solid-Phase Extraction, Charles Bui

Masters Theses

A separation scheme has been developed by utilizing Solid-Phase Extraction cartridges in order to isolate and characterize the charge of metals and their complexes in natural waters. These species can be analyzed by Atomic Absorption Spectroscopy (AAS), Inductively Coupled Plasma (ICP), and Ultraviolet-Visible Spectrophotometry (UVVIS).

This separation scheme would permit the determination of the concentration of metals, as well as providing information about the forms in which the metals exist, e.g., charge of metallic complexes.

Synthetic metal complexes were prepared in the laboratory in order to study the separation scheme as well as trying to understand the binding stability of …

Thermodynamic Properties Of Mixtures Of Aqueous Solutions Of Hydrochloric Acid And Cadmium Chloride, Copper Chloride, Manganese Chloride, And Zinc Chloride, Samia A. Kosa

Masters Theses

The densities of mixtures of aqueous solutions of hydrochloric acid and cadmium chloride, copper chloride, manganese chloride, and zinc chloride have been measured at constant ionic strengths of 1.0 and 3.0 molal at 25 °C. In the case of HCl, CdCl₂ , and ZnCl₂ the literature data were refit using Pitzer' s apparent molal volume equation and the binary solution parameters were determined. Density data were used to determine the volume of mixing (∆V_m). Data from Torok and Berecs were combined with our data for the mixtures with CuCl₂ and MnCl₂. Pitzer's volume …

Investigation Of Electron Transfer From Carbonylmetallate Anions To Electron Acceptors, Joseph Kofi Agyin

Masters Theses

This study investigated electron transfer potential of the carbonyl-metallate anions cyclopentadienylirondicarbonyl and methylcyclopentadienyliron-dicarbonyl anions to the electron acceptors 2,2-dinitropropane, 1,1-dinitrocyclohexane, $\alpha$,p-dinitrocumene, methyl cyclopentadienyl-mercury(II) chloride and iodide.

The findings from this study indicated that: (a) the expected products could not be obtained from reactions of the anions with the dinitro-substrates, and (b) the mercurials reacted with the anions but the expected products, (ferrocene and methylferrocene), was the minor product and an unexpected (methyl) cyclopentadienylirondicarbonylmercury(II)-chloride or iodide was the major product.

Method Development In Coal Extraction, Yunsong Tong

Masters Theses

Organic sulfur compounds in coal should be removed as completely as possible in order to make coal "clean" during its usage. Before any method for coal desulfurization can be investigated, the structure of coal should be known. Soluble substances in coal are more easily analyzed by spectroscopic methods than is the insoluble coal. The goal of this research is to separate soluble organic sulfur compounds from the original coal by pyridine extraction. The weight percentages of the coal extracts obtained from three different coal samples by single step extractions ranged from 8% to 30%. The coal extractability could also be …

Synthesis And Characterization Of Transition Metal Polypyridyl Complexes With A Novel 1,10-Phenanthropteridinedione Ligand, Huakai Huang

Masters Theses

A new alloxazine ligand (1; "Pptd"), produced by the condensation of 1,10-phenanthroline-5,6-dione with 5,6-diamino-1,3-dimethyluracil, and several transition metal complexes containing this ligand, have been synthesized. The Pptd ligands attach to Ru(II), Co(II), or Re(I) metal centers through the phenanthroline linkage to form stable polypyridyl complexes. The spectral and the electrochemical characterization of Pptd complexes of Ru(II), Co(II), and Re(I) is presented.

Pptd is capable of being reduced (across the pyrazine nitrogens) by two H-atoms. When coordinated to Ru(II), Pptd forms stable complexes which retain the robust characteristics and electrochemical activity of other Ru(II) polypyridyl species. In addition, Ru(II) complexes of …

Synthesis Of Symmetric And "Mixed-Ligand" Homocyclopentadienyl Ruthenocenes, John Adjeiku Amanfu

Masters Theses

No abstract provided.

Synthesis Of Organometallic Polymers, Po-Chang Chiang

Masters Theses

By the middle of the nineteenth century, organic chemists found high molecular weight compounds as by-products of some of their experiments. These compounds were thought of as products of a failed reaction. It was not until sixty years ago that the first polymers were deliberately synthesized. Today polymers are used in almost every facet of life and they are becoming more important with each passing day.

This research project focused on synthesizing conducting organometallic polymers. By linking aromatic rings with transition metals, the resultant polymers should have good electrical conductivity because of the interaction of (a) the p electrons on …

Single And Double Ionization Of Helium By Highly Charged Sulfur Ions, Karen M. Lifrieri

Masters Theses

Single and double ionization of helium by highly charged sulfur projectiles is investigated over an energy range of 0.16 to 1.6 MeV/u. Absolute cross sections for the processes of pure ionization, ionization associated with single capture, and ionization associated with single loss by S^6,13+ projectiles were experimentally determined and compared with previous results and theories. Ratios of double-tosingle ionization for each outgoing projectile charge state were also determined and compared with theory. The pure ionization ratios for S⁶⁺ at the highest energies investigated show the q²/E dependence predicted by Knudsen et al. (1984). For S^{13+ …}

Butenolide Synthesis Via Cation-Initiated Ring Expansion/Elimination Of Β-Lactones, Jianhua Huang

Masters Theses

An area of recent research in the Black research group is an exploration of the potential of cation-initiated β-lactone ring expansions, accompanied by the elimination of a proton or other electrofuge, as a protocol for the synthesis of multisubstituted butenolides.

Γ-Bromo β-lactones were prepared via bromolactonization of the appropriate β,Γ-unsaturated acids under basic conditions. The nucleofugal bromine atom on the Γ-carbon was then employed to effect carbocation formation adjacent to the lactone ring oxygen atom; the most efficacious reagent combination was found to be silver nitrate in refluxing acetic acid. Generation of this cation initiated a migration of the β-lactone …

Iron Tricarbonyl Derivatives Of Ditertiary Phosphines, Xi Chen

Masters Theses

In this work we have explored reactions of coordinated diphenylvinylphosphine with coordinated diphenylphosphine. Starting materials, (OC)₄FePPh₂CH=CH₂, trans- (OC)₃Fe(PPh₂CH=CH₂)₂, (OC)₄FePPh₂H, and trans- (OC)₃Fe(PPh₂H)₂ were successfully prepared from known procedures. The bimetallic complex, (OC)₄FePPh₂CH₂CH₂PPh₂Fe(CO)₄, was obtained in 69% yield from the reaction of ((OC)₄FePPh₂CH=CH₂ with (OC)₄FePPh₂H. The trimetallic complex, (OC)₄FePPh₂CH₂CH_{2 …}

New Reagents And Reactions For Desulfurization Of Coal, Shan Wang

Masters Theses

Searching for new reagents and reactions for pre-combustion desulfurization of coal was the goal of this work. In this study, modifications of mild desulfurization reactions, which were found to work with organosulfur model compounds, have been investigated systemetically for improvements in sulfur removal and reduction of reagent cost. The screening of reagents and new reactions utilized substituted thiophenes plus aryl sulfides as the initial models for organosulfur compounds in coal. Tetrahydrofuran extracts of Illinois Basin Coals were also used as second generation targets for desulfurization reactions.

Dibenzothiophene was converted to biphenyl using potassium metal/tetrahydrofuran without the addition of electron transfer …

Studies On Improving The Regioselectivity Of Reactions Of Sucrose: The Role Of Molecular Recognition And Polymer Supported Syntheses, Ran Jiang

Masters Theses

The world economy is critically dependent upon natural resources. Because sucrose can be inexpensively produced in large quantities and refined to a purity unequalled by almost all other natural products, it has been exploited as an industrial raw material for many years, primarily as a sweetener. A major difficulty in utilizing sucrose as an industrial feedstock is the lack of regioselectivity in synthetic reactions due to its eight hydroxyl groups of similar reactivity.

The long range goal in this work is to apply the technique of molecular recognition by template imprinting to the creation of a material that will bind …

Selected Studies On Certain Iron Sandwich Complexes, Mashitah M. Yusoff

Masters Theses

In these studies, the synthesis of [2.3](1,3)cyclopentadiendoparacyclophane was attempted. Like ferrocene and [2.2]paracyclophane, it is expected to exhibit transannular π-electronic interaction throughout its molecular structure and therefore, one dimensional semiconductivity.

The preparation of dialkylferrocenes had resulted in complex inseparable mixtures. Due to the fluxional nature of its intermediates, their conversion to stable Diels-Alder adducts would facilitate analysis. In this project, certain Diels-Alder adducts of bis-cyclopentadienyliron dicarbonyl intermediates were prepared for analysis.

Very few transition metal complexes of pyrrole are currently known. [2.2](2,5)Pyrroloparacyclophane was perceived to be stable especially as a part of an iron sandwich complex. The final phase …

Reductive Cleavage Of Cyclopentadienylmanganese Tricarbonyl, Mani S. Iyer

Masters Theses

Since the isolation of ferrocene in 1951, it has been shown to behave like benzene and may be acylated, sulfonated, metalated, and arylated. Like benzene, it also resists hydrogenation.

Daniel Trifan and Louis Nicholas (1957) were the first to show that ferrocene can be smoothly degraded by lithium and ethylamine. The isolation of free cyclopentadienyl ion on hydrolysis of the reaction mixture indicates that the cleavage leads initially to cyclopentadienyl lithium salt. A similar procedure applied to cyclopentadienylmanganese tricarbonyl also resulted in the formation of cyclopentadienyl lithium salt. This, when added to ferrous chloride, gave ferrocene. This technique can be …

Micellar Catalysis Of Hydrolysis Of Substituted Hydroxamic Acids With Perfluorooctanoic Acid, Zhongyuan He

Masters Theses

The work demonstrated the effects of differently located and substituted phenyl groups, as well as aliphatic groups in the hydroxamic acids, on micellar catalysis with perfluorooctanoic acid as the reactive counterion surfactant in aqueous acetonitrile solution.

Kinetic rate constant-surfactant concentration profiles for the decano-, 2,5-dimethylphenylaceto-, 4-isopropylphenylaceto-, 4-phenylbutano-, and 6-phenyl-hexanohydroxamic acids were examined and analysis on the data obtained were reported.

The pseudo-phase ion exchange (PPIE) model has been satisfactorily applied to explain the observed micellar effects.

Further investigation into more appropriately substituted hydroxamic acids is suggested in order to obtain a more complete set of data and further evaluation.

Reactivities Of Some Aromatic Compounds At Supercritical Water Conditions, Chun-Cheng Tsao

Masters Theses

The goals of this study are the removal of nitrogen from the extraction products of coal by Supercritical Water and the development of an understanding of the reactions leading to this removal. Six model compounds with structures similar to the intermediates of the coal liquefaction processes were studied. Benzylamine generated toluene through hydrogen abstraction after the C-N bond rupture. To a lesser extent, the oxidation of the benzylic carbon took place leading to benzene formation. Both reaction pathways occurred with equal probability for benzylidenebenzylamine, producing comparable yields of benzene and toluene. Benzaldehyde generated benzene through the oxidation/decarboxylation sequence. Benzyl alcohol …

An Analysis Of Dissolved Organic Compounds And Their Contribution To Iron Complexation In The Shallow Leachate Plume Of The West Kl Landfill Kalamazoo, Michigan, Eric Fahle

Masters Theses

High concentrations of dissolved iron are present in downgradient groundwater samples adjacent to the western border of the West KL Landfill. Analysis by Rudder (1988) of groundwater samples indicates oversaturation of selected iron oxides, iron sulfides and siderite in monitoring wells TW-4 and M3.

Previous research suggests that pyrogallol, gallic acid, tannic acid and similar organic compounds may retard the oxidation of ferrous iron in the shallow leachate plume of the West KL landfill (Rudder, 1988). Present research utilizing solid phase extraction, reverse phase high performance chromatography, Fourier transform IR spectrophotometry, UV/Visible spectrophotometry, and gas chromatography/mass spectroscopy indicate that pyrogallol, …

Development Of Ruthenium Vinylbipyridine Modified Electrode Surfaces For Use In Chemiluminescence-Based Detection Systems, Matthew F. Piescinski

Masters Theses

Based upon the chemiluminescent properties of [Ru(bpy)₃]²⁺ and the proven analytical applications of that complex in the detection of easily reduced anions in solution, a chromatographic detection system was designed utilizing an immobilized form of the Ru(ll) complex. The objective was to create, by electropolymerization, a regenerative chemiluminescent surface on a working electrode. Reductive electropolymerization was accomplished by the use of a [Ru(bpy)₃]²⁺ analog containing the ligand vinylbipyridine. Two analogs, [Ru(vbpy)₃][PF₆]₂ and [Ru(phen)₂(vbpy)][PF₆]₂ were polymerized on platinum, glassy carbon and indium-doped tin oxide working …

Kinetics Of The Metal-Exchange Reaction Between Ortho-Phospho-Dl -Serinenickelate(Ii) And Copper(Ii), Jeffrey M. Peterman

Masters Theses

No abstract provided.

Indirect Photometric Chromatography Of Inorganic And Organic Anions Using Benzoate As An Eluent, Shahab A. Shamsi

Masters Theses

For many years the determination of common inorganic and organic anions was hindered by the lack of adequately sensitive analytical techniques. The determination of these anions was laborious and time consuming (e.g. titration, precipitaion, gravimetric analysis etc.). Because of the development of high-performance liquid chromatography, the anion exchange separation of simple inorganic and organic anions is now possible. Now, there are a broad and ever-increasing array of chromatographic methods supplanting these older chemical methods. However, detection is still a problem, but indirect detection provides a practical route for the detection of non-chromophoric inorganic and organic anions.

This dissertation describes the …

Molecular Mobility In A Model Polymer Composite, Joan Ethel Gambogi

Masters Theses

"The adsorption of aminoalkysilane coupling agents onto silica surfaces and the interaction of these functional silanes with a bismaleimide and an epoxy resin has been studied using solid-state NMR techniques. ¹³C CP-MAS was used to confirm the bonding between the silence and bismaleimide (BMI) resin and elucidate the nature of the crosslinking reaction of BMI. Deuterated coupling agents were synthesized and adsorbed on silica surfaces. The motional dynamics were probed using deuterium solid-echo NMR. It was determined that the motion of the alky portion of the coupling agents was consistent with gauche migrations (gtt ↔ tig) and pair gauche …

A Spectroscopic Study Of Charge Distribution In Transition Metal Bridging Hydride Complexes, Shixiong Chen

Masters Theses

A series of transition metal bridging hydrides of general formula C[μ-HM₂(CO)₁₀] (C = tetraethylammonium, Et₄N⁺; tetraphenylphosphonium, Ph₄P⁺; of bis(triphenylphosphine)iminium, PPN⁺; M = Cr or W) were synthesized from M(CO)₆ and NaBH₄ bt known methods. As a means of obtaining information about the charge distribution in these complexes, they were allowed to interact in solution and the solid state with triphenylphosphine oxide (TPPO) on the premise that this electron donor could identify sites of relative electron deficiency. Evidence for interaction was sought via solution and …

Derivatization Of Coal By Alkylation And Lithium Iodide Treatment, Cynthia L. Ludwig

Masters Theses

The hypothesis that hydrogen-bonded ethers in coal could be cleaved by reaction with lithium iodide in pyridine to form new phenol groups was investigated for coals #2, 3, and 5 plus their alkylated derivatives from the Argonne Premium Coal Sample Program. Changes caused by alkylation and reaction with LiI were monitored by solvent extraction yeilds, solvent swelling, FT-IR and Size Exclusion Chromatography (SEC).

Solubilities of alkylated coals are rank and oxygen functionality dependent. Evidence supports the hypothesis that the solubilization mechanism is dependent on the extent of hydrogen-bonding in the coal. Elimination of hydrogen-bonds through alkylation increases toluene solubility and …