Chemistry Commons^™

The Anodic Stripping Voltammetry Determination Of Trace Elements In Coal Ash, Jesus Montoya

Masters Theses & Specialist Projects

The application of anodic stripping voltammetry (ASV) to the determination of several trace metals in coal ash was studied.

An ashing and ash digestion method was developed which limited the total salt and acid concentration of the analyte solutions, a necessary step for routine analysis. The simultaneous determination of cadmium, copper, lead, and zinc in eight Pennsylvania State University Coal Bank Samples and in the National Bureau of Standards SRM 1632a coal sample were made. Chromium was separated from the prepared coal ash solutions and determined independently in the form of chromate(VI).

All values determined by ASV methods were in …

Cyclic Voltametry Studies Of Various Ylide Metallocenes, Mark Mojesky

Masters Theses & Specialist Projects

The redox potentials of [Fe(CpSMe₂)₂]²⁺ (CpSMe₂= dimethysulfoniumcyclopentadienflide), [Ni(CpSMe₂)₂]²⁺, [Co(CpSMe₂)₂]²⁺, [Mn(CpSMe₂)₂]²⁺, (CpPPh₃)HgBr₂ (CpPPh₃= triphenylphosphoniumcyclopentadienylide), (CpPPh₃)HgCl₂, and MoPC (PC = phthalocyanine) were examined using cyclic voltammetry (CV). The experimentation was carried out in a temperature controlled environment. With the exception of the mercury and molybdenum complexes, the solvent system consisted of 15 milliliter mixture of acetonitrile and water. Due to the solubility problems of the mercury bromide complex, …

The Anodic Stripping Voltammetric Analysis Of Chromium Using The Hanging Mercury Drop Electrode, John Fugate

Masters Theses & Specialist Projects

The Hanging Mercury Drop Electrode (HMDE) is used in the anodic stripping analysis of ppm concentrations of chromium. The effects of such parameters as ionic strength, polymeric film formation, and the use of the chromate-sodium acetate standard are interpreted in terms of the electro-chemical and physical properties of chromium in the +3 and +6 oxidation states.

A Study Of Ylide Extractions Of Mercury In Fish And Water Using Cold Vapor Flameless Atomic Absorption Techniques, Howard Vail

Masters Theses & Specialist Projects

Cold vapor flameless atomic absorption spectrophotometry is an analytical method used in the determination of mercury. Its sensitivity is less than one part per billion using a 100 milliliter sample, and there are virtually no interferences from other metal ions. The method is best carried out making use of a permanganate-persulfate oxidation step with heat.

The ylide, triphenylphosphoniumcyclopentadienylide (CpPPh₃), which extracts mercury almost quantitatively from water, was used in attempts to remove mercury from exposed goldfish. Though not toxic to the fish, CpPPh₃ did not significantly lower mercury levels. Evaluation of CpPPh₃ as a possible phase …

The Effects Of Bridging Ligands On Anodic Stripping Voltammetric Analysis, Larry Beasley

Masters Theses & Specialist Projects

Anodic stripping voltammetry (ASV) is an electroanalytical method used in the determination of trace metals in solutions volumes of 20 milliliters or less. Generally, 10^-6 M concentrations are routinely analyzed.

The analysis of Zn(II), Cd(II), and Cr(III) by ASV was Investigated, and the effects of introducing the bridging ligands, cyanide and thiocyanate into solutions of these metal ions was examined. These effects include a cathodic shift in the reduction potentials of the metals, and ASV signal changes ranging from small increases in peak currents to a total loss of peak-current signals, depending on the concentration of the ligand added.

Kinetic Studies Of Polymer-Bound Rhodium (I) Hydrogenation Catalyst, Nee-Yin Chou

Masters Theses & Specialist Projects

For many years, it has been customary to classify catalysts as homogeneous or heterogeneous. Generally, the former are more active and more selective. But the major disadvantage of the homogeneous catalysts is the need to separate the reaction products and to recover the catalyst, which is often somewhat more expensive than a "classical" heterogeneous catalyst. It has been considered, especially in the last ten years, that there might be advantages in chemically binding a homogeneous catalyst to a solid support.

Polymer-bound, anthranilic acid anchored rhodium (I) catalysts have been prepared. The rate of hydrogenation of cyclohexene has been studied quantitatively, …

Spectroscopic Study Of Ni(Ii)-4, 4’, 4’’, 4’ ’’ – Tetrasulfophthalocyanine In Aqueous Solution, Issa Ishaq Jabra

Masters Theses & Specialist Projects

It was determined spectrally that a monomer-dimer equilibrium exists in aqueous solutions of Ni-TSPC^4- over a concentration range of 5 x 10^-8 – 10^-4 M. Equilibrium measurements were made under natural ionic strength conditions at 29°, 39° and 49°C. The values obtained for the equilibrium constants at 29°, 39° and 49°C were 2.4 x 10⁸, 6.6 x 10⁷ and 2.9 x 10⁷ M^-1, respectively. These results indicated that the equilibrium strongly favors dimer formation. This study also showed that nickel is second to copper in enhancing the dimerization of metallotetrasulfophthalocyanine complexes. …

Electron Transfer Reactions Of An Osmium (Ii) Polypyridyl Complex With Oxidizing Agents, Stephen Mcclanahan

Masters Theses & Specialist Projects

Redox rates between polypyridyl osmium (II) complex, OsCl(py)₃(bipy)⁺, with tris(1,10-phenanthroline) cobalt (III), Co(phen)₃³⁺, and Ce(IV) were examined in aqueous solution. Both reaction systems exhibited second order kinetics. The osmium (II) - cobalt (III) redox reaction was found to have a rate constant of 2.3 x 10⁵ M^-1 sec^-1 at 22°C and µ = 0.003M from which the isotopic electronic exchange rate constant for the OsCl(py)₃(bipy)^+/2+ system was estimated to be 1.5 x 10⁹ M^-1sec^-1.

Ionic strength effects on the Ce(IV) - Os(II) …

Photochemistry Of Heteroaromatic Analogs Of Β-Methyl-Β-Nitrostyrene, Dale Willis

Masters Theses & Specialist Projects

2-(2-nitropropenyl)thionhene, 2-(2-nitropropenyl) pyrrole, and 2-(2-nitropropenyl) furan were prepared and irradiated in undenatured 95% ethanol and 2% aqueous acetone. The pyrrole derivative was found to undergo a slow photodecomposition to tars. The thiophene derivative produced 60% of an α-oximino ketone and 30% of an oxazine cyclization product when irradiated In ethanol. When irradiated in acetone 47% of the oxime was produced in addition to 7% of the oxazlne. The furan derivative produced 12% of an α-oximino ketone and 51% of an oxazine cyclization product when irradiated in ethanol. When irradiated in acetone 15% of the oxime and 32% of the oxazine …

Redox Study Of Cobalt(Ii)-Cobalt(Iii) Polypyridyl, Larry Long

Masters Theses & Specialist Projects

The rate of reduction of [Co(dipy)₃]³⁺ by [Co(tripy)₂]²⁺ has been examined in six nonaqueous solvents and water. The kinetic results in these solvents were compared with those obtained in nine other solvents where the same reaction was investigated. Activation parameters were obtained over a temperature range of 5° to 50°C with the ionic strength at 0.0027 or 0.0046 M. The slowest rate of electron transfer was found in acetonitrile while the fastest occurred in acetophenone, the solvent of lowest dielectric constant. A linear correlation between ln k and the reciprocal dielectric constant of the …

The Design And Construction Of A Nitrogen Laser And Its Use To Pump A Tunable Dye Laser To Measure The Multiphoton Ionization Spectrum Of Molecular Iodine, James Kintigh

Masters Theses & Specialist Projects

A nitrogen laser was constructed for use in multiphoton ionization studies. The short pulse duration and highly intense pulse make the nitrogen laser ideal for pumping a dye laser.

By using the nitrogen laser to pump a tunable dye laser, the multiphoton ionization spectrum for molecular iodine vapor was obtained for the visible spectrum between 23,188 cm^-1 (430 nm) and 16, 304 cm^-1 (615 nm) using pulsed electronics and a parallel plate ionization chamber. The ionization occurs in this region upon the absorption of four or five photons. The ionization appears to take place via a three-step process. …

Synthesis Of Crown Ethers & Stereochemistry Of 1, 4-Ditertiarybutyl-1, 4-Dihydronaphthalene, Abdolreza-H-Hossein Nejad

Masters Theses & Specialist Projects

A. Cyclization of ethylene oxide in the presence of transition metal salts was studied. Several reactions with different catalysts were tried and some of these reactions produced compounds which show only one sharp singlet in their NMR spectra. These products were also soluble in benzene. The solubility of potassium permanganate in this mixture suggests the presence of cyclic polyethers. In spite of the above observations, all attempts to liberate cyclic ethers from their metal complexes were unsuccessful.

B. In the second project, the stereochemistry of 1,4-ditertiarybuty1- 1,4-dihydronaphthalene was elucidated using ¹H and ¹³C NMR. For this purpose, other …

Removal Of Nitrogen & Sulfur From Coal-Derived Liquids & Identification Of Nitrogen & Sulfur Compounds In Coal-Derived Liquids, Tay-Yean Lin

Masters Theses & Specialist Projects

Since all the nitrogen compounds that have been identified in coal-derived liquids in the past have been basic in character, the effect of an acid-wash on the nitrogen content of coal-derived liquids was examined. Because sulfuric acid is the cheapest of the commerical strong acids, it was the natural choice, and its use was examined in detail. The greater the concentration of the sulfuric acid used, the greater the amount of nitrogen removed. :he sulfur compounds in coal-derived liquids were not removed noticeably by extraction with sulfuric acid. Column chromatography is a possible technique for removal of nitrogen compounds. The …

The Photochemistry Of Alpha, Beta-Unsaturated Nitro Compounds, Liang-Wuen Chang

Masters Theses & Specialist Projects

1-(9-Anthry1)-2-nitropropene and 1-(3-pyridy1)-2-nitropropene were prepared and irradiated with ultraviolet light.

Irradiation of 1-(9-anthry1)-2-nitropropene, in which the ethylene group was twisted out of the plane of the aromatic ring and the resonance stabilization between the ethylene group and the aromatic ring was limited , gave only cis-trans isomerization.

Irradiation of 1-(3-pyridy1)-2-nitropropene gave an oxime. The effect of added HC1 on the reactivity of 1-(3-pyridy1)-2-nitropropene showed that the rate for the formation of oximinoketone was decreasing., while irradiation of 1-phenyl-2-nitropropene with HC1 showed that the rate for the formation of oximinoketone was increasing.

From these observation, steric factors and resonance factors are …

Photochemistry Of Alpha, Beta-Unsaturated Nitro Compounds, Charles Elmore

Masters Theses & Specialist Projects

A total of twelve α ,β - unsaturated nitro compounds of the form

Ar-C=C-NO₂

| |

H R

(where Ar=phenyl, o-methylphenyl, mesityl, α - naphthyl, and β - naphthyl; R=hydrogen, methyl, ethyl, and phenyl) were prepared and irradiated with ultraviolet light. When the corresponding α - oximinoketone was formed, it was recovered and identified. Six of the α , β - unsaturated nitro compounds and one α - oximinoketone had not been previously reported. Yields of irradiation products were determined and a kinetic study performed on these.

The effect of substituents size at the β - position of α …

Computer Simulation Of The Rotational Spectrum Of A Symmetric Top Molecule, W. Scott Wells

Masters Theses & Specialist Projects

Given the proper equations and the appropriate set of selection rules, a computer can be programmed to simulate the spectrum of a molecule. This study deals with the rotational spectrum of a symmetric top molecule. The program itself was written in several subroutine blocks. By doing this the computing time was reduced by 70% over similar programs.

The program can be used to simulate the spectrum of a molecule if the transition polarization type and the rotational constants are known. However, if the type of transition polarization or constants is unknown, the program can be used as a tool for …

A Comparison Of Various Pattern Recognition Techniques, Larry Wood

Masters Theses & Specialist Projects

A comparison of the reliability of three pattern recognition classifiers has been made using data having a great amount of variation. The basic concepts of the Linear Learning Machine, the K Nearest Neighbor Classifier, and the Potential Function Classifier are presented. Prediction of whether a student would pass or fail freshmen Chemistry 120 was made, based on various test results. The Linear Learning Machine was found to be an unworkable classifier for this kind of data. Both the Potential Function Classifier and the K Nearest Neighbor classifier were acceptable with the Potential Function Classifier being generally a better classifier.

Conformational Analysis Of 1-Tertiarybutyl-1, 4-Dihydronaphthalene A Turnover From Srni To Sni Mechanism, Su-Jen Huang

Masters Theses & Specialist Projects

The cyclohexadiene porition of 1-tertiarybutyl-1, 4-dihydronaphthalene exists in a puckered rather than planar conformation at room temperature, with approximately equal populations of the isomer with the t-butyl group “axial” and “equatorial.” Analysis of chemical shifts and coupling constants was aided by use of a LAOCOON III program.

Extraction Rate Study Of Ni(Iii) Oxinate & Separation Of Cu(Ii) & Ni(Ii) With Oxide Based On Differences In Rates Of Extraction, Somchai Taichilassunthorn

Masters Theses & Specialist Projects

This study was conducted with metal ion concentrations in the range of parts per million and used batch extraction techniques to study the non-equilibrium extraction of Cu(II) and Ni(II) oxinates. Contrary to other authors, atomic absorption was used exclusively for the analysis of phases.

The two main areas of investigation in this study were:

1. Kinetics study of extraction of Ni(II) oxinate.
2. Separation of Cu(II) and Ni(II) with oxine based on differences in rates of extraction.

It was the purpose of this work to study the extraction of Cu(II) and Ni(II) with oxine in chloroform. This particular pair of elements was …

Some New Metallocenes, Larry Warfield

Masters Theses & Specialist Projects

The synthesis and characterization of some new metallocenes is discussed. These organometallic compounds contain some of the first reported pi-complexes between an aromatic ylid, triphenylphosphoniumcyclopentadienvlide. and some transition metals.

Also reported is the synthesis of some new mercury halide metallocenes involving dimethylsulfoniumcyclopentadienylide as the sigma bonded organic substrate.

Photochemistry Of Beta-Methyl-Beta-Nitrostyrene And Its Derivatives, Mohammad Z. Kassaee

Masters Theses & Specialist Projects

o-CH₃, o-CH₃O, m-CH₃O and p-CF₃-β-methyl- β-nitrostyrene (compounds not previously reported) were synthesized using the method of Lappin¹³ and Robertson.¹⁴ These styrenes were irradiated in the U.V. region. The yield of corresponding oximes varied from 85 to 100% in aqueous ethanol. This variation in yield of the oximes was attributed to the effect of the substituent on the phenyl rings of the corresponding styrenes. Electron donating substituents promoted the nitro-nitrite rearrangement and electron-withdrawing groups inhibited this rearrangement. A mechanism is proposed for this reaction which unifies and includes ideas proposed by …

New Applications Of The Mannich Reaction, Yu-Fang Wang

Masters Theses & Specialist Projects

French chemists found that the reaction of trifluoroacetic anhydride with the N-oxide of trimethlyamine leads to the methylenedimethylimmonium trifluoroacetate. This salt is considered to be the actual reagent in the Mannich reaction conducted with dimethylamine and formaldehyde. Indeed use of this salt gives higher yields than those obtained via the classical Mannich procedure. This salt could be distilled under vacuum (5 x 10^-2 mm) and reacted with phenylmagnesium bromide to give an 80% yield of benzyldimethylamine. The trimethlsilyl ethers of ketones were employed as intermediates and exhibited regioselectively. For unsymmetrical ketones, the more stable enol was formed thermodynamically and …

Ua66/7/2 Newsletter, Wku Chemistry

WKU Administration Documents

Newsletter created by and about the WKU Chemistry department.

Anion Assisted Redox Rates Between Cobalt (Ii) - Cobalt (Iii) Polypyridyl Complexes In Acetophenone, Seyed Garmestani

Masters Theses & Specialist Projects

The effects of ionic strength and various anions on the rate of electron transfer between tris(2,2'-dipyridine) cobalt(III) and bis(2,2',2"-tripyridine) cobalt(II) complexes have been examined in acetophenone. The redox rate was found to increase with increasing ionic strength in both the presence and absence of added salts. The reaction was first order with respect to each reactant and second order overall in all cases. The influence of the C10₄, BF₄, and B(C₆H₅)₄ anions on the reaction rate was studied with their order of effectiveness being: C10₄- > BF₄ >> B(C_{6 …}

A Spectrophotometric Equilibrium Study Of Nickel(Ii)-3, 4', 4", 4'"-Tetrasulfophthalocyanine, Stephen Lowery

Masters Theses & Specialist Projects

There have been several studies made on the effects of various central metal ions on the aggregation of tetrasulfonated Phthalocyanine dye complexes in aqueous solution, but there have been no studies made on the aggregation of the nickel(II)-4, 4', 4", 4'"-tetrasulfoohthalocyanine (Ni^II-TSPC) complex. Therefore, a study of the effects of nickel(II) on the aggregation of its aqueous tetrasulfonated Phthalocyanine dye complex was Proposed so that a comparison might be made with nrevious studies of central metal ion effects. It was found, however, that Ni^II-TSPC gives a much higher degree of aggregation in water than the metal …

Electronic Transitions Of Metal Complexes With Triphenylphosphine As A Ligand, Thomas Zimmer

Masters Theses & Specialist Projects

The spectra of transition metal complexes with triphenylphosphine have been measured near 260 nm and the results interpreted in terms of perturbation of the it electron system of the phenyl ring. All complexes studied show sou degree of delocalization of the d-orbital electrons of the metal into the phenyl ring. However, for first row transition metals, the primary affect was found to be polarization of the phenyl ring due to the presence of the metal ion. For second and third row transition metal ions, the primary effect was found to be metal-ligand back-bonding. However, the effect of polarization of the …

Ua66/7/2 Newsletter, Wku Chemistry

WKU Administration Documents

Newsletter created by and about the WKU Chemistry department.

Esterase Activity In The Greater Wax Moth Larvae, Daphne Lin Pai

Masters Theses & Specialist Projects

Some properties of esterases of the greater wax moth larvae, Galleria mellonela (L.), were examined and the enzymes partially purified. Several buffer systems were tried and it was found that tris buffer was most suitable. The tris buffer resulted in less hydrolysis of the acetylsalicylic acid. Esterase activity was determined with acetylsalicylic acid in tris buffer, pH = 7.85, 0.05 M. The enzymes were partially purified by combination of acetone powder preparations, ammonium sulfate precipitations and gel filtration.

The ratio of esterase activity to protein content was increased 1.03 fold by acetone powder preparation and 1.5 fold by 70% ammonium …

Photochemistry Of Beta-Methyl-Beta-Nitrostyrene & Its Derivatives, Donald Tang

Masters Theses & Specialist Projects

A series of β- methyl-β-nitrostyrenes have been synthesized and subjected to ultraviolet irradiation. A new technique has been developed for synthesis of 1-phenyl-1,2-propanedione-1-oxime and its derivatives by irradiation of the corresponding styrene. The yields of the oximes were almost quantitative [except 1-(p-nitrophynyl)-1,2-propanedione-1-oxime and 1-(m-nitrophenyl)-1,2-propanedione-1-oxime]. It has been found that irradiation of the appropriate styrene is a very simple, efficient, and general procedure for the synthesis of 1-phenyl-1,2-propanedione-1-oxime and a number of its derivatives. A number of derivatives of β- methyl-β-nitrostyrene (p-CH₃, p-Ch₃0, p-Cl, p-No₂, and m-NO₂) were irradiated. It was found that …

Photochemistry Of Beta-Methyl-Beta-Nitrostyrene, Peggy Chen

Masters Theses & Specialist Projects

It has been postulated that acetone is the best solvent for the photochemical rearrangement of β-methy1-β-nitrostyrene to 1-phenyl-1, 2-propanedione-1-oxime and it has been postulated to be a sensitizer for this rearrangement. It has also been suggested that the methyl group on the beta-carbon is required for the proper orientation of the nitro group for rearrangement. The irradiation of β-methyl-β-nitrostyrene in several solvents has been studied and the yield of oxime has been recorded. It has been found that several solvents gave yields of oxime higher than that recorded for acetone. We do not, therefore, believe acetone to be necessary to …