Chemistry Commons^™

Analytical And Other Applications Of Some Quaternary Ammonium Compounds, Robert Grant Dosch

Chemistry and Chemical Biology ETDs

Analytical and other applications of some quaternary ammonium compounds were studied. Conditions are described for the quantitative determination of perchlorate by precipitation as tetra-n-pentylammonium perchlorate. Results of qualitative studies of interferences from other anions and quantitative studies on the separation and determination of perchlorate in the presence of chlorate are presented. With careful work, relative errors of ± 0.2% can be expected in the range of 50-100 mg of perchlorate, ± 1.0% in the 10-50 mg range, and ± 5.0% in the range from 2-10 mg of perchlorate. A method is described for the separation and determination of Ta in …

A Theoretical Analysis Of The Electronic States Of 2nd And 3rd Row Transition-Metal Complexes;-A Spectroscopic Investigation Of D5 And D6 Systems, Howard James Clifford

Chemistry and Chemical Biology ETDs

A theoretical and experimental investigation of a number of transition-metal complexes was conducted. The compounds of primary interest were six-coordinated complexes containing group VIII metal ions belonging to the second and third transition series. The investigation involved the synthesis and purification of the compounds, the measurement of absorption and emission spectra and luminescent lifetimes, and the analysis of the observed spectral properties using a crystal-field model based on solutions of large secular determinants. The effects of variations of the Racah parameters on the energy­level diagrams of dⁿ ions (n = 2, 3, ... , 8) in an octahedral crystal …

Liquid Scintillators. The Photooxidation Of 2,5-Diphenyloxazole, Margaret E. Ackerman

Chemistry and Chemical Biology ETDs

Mackay had found that prolonged ultraviolet irradiation of solutions of 2,5-diphenyloxazole (PPO) (1) in toluene resulted in the formation of an insoluble crystalline product 2 which accumulated above the meniscus; the formation of 2 was dependent upon the presence of dissolved oxygen and water in the solutions. The Compound 2 was not a simple degradation product of PPO (1); elemental analysis was compatible with the empirical formula C₂₂H₁₇O₅N and the thermal decomposition of 2 gave equal molar amounts of carbon monoxide, benzoic acid, and dibenzamide. The study described in this dissertation was initiated to …

A Quantum Mechanical Investigation Of The Heh3+ Energy Surface, Merle J. Benson

Chemistry and Chemical Biology ETDs

An all-electron ab-initio calculation of the energy surface for the reaction He+ H⁺₃ → HeH⁺ + H₂ was performed using a 9slp gaussian basis set for helium and a 4slp gaussian basis for hydrogen. Reaction paths calculated were of C_2V, C_S, and C_3V symmetry. The lowest energy configuration was found with the molecule in C_2V symmetry with the three hydrogen atoms in an equilateral triangle of side length 1.64 a.u. with the helium atom 3.85283 a.u. from an apex of the triangle. The molecule was found to remain in C …

Effects Of Hydrocarbon Chain Length On The Thermodynamics Of Formation Of Bis(N-Alkylamino)-Silver (I) Complex Ions, Don J. Temer

Chemistry and Chemical Biology ETDs

As part of a comprehensive study of the thermodynamics of conformational changes of n-alkyl groups in aqueous solution, the equilibrium constants, enthalpy changes, and entropy changes have been measured for the stepwise formation of bis(n-alkylamino)silver(I) complex ions at 25° in dilute aqueous solution. The attachment of the charged Ag⁺ to the end of the amine molecule is thought to cause changes in the conformation of the n-alkyl chain. The effects of these conformational changes on the formation constants, enthalpy changes, and entropy changes of the Ag⁺ complexes are discussed and compared with the effects on the formation constants, …

A Spectroscopic Investigation Of Electron Transfer Transitions In Osmium (Ii) Complexes, Brian J. Pankuch

Chemistry and Chemical Biology ETDs

Osmium (II) complexes containing organic coordinating ligands 2.2'-bipyridine, 1.10-phenanthroline, 2.2' .2"­terpyridine were studied spectroscopically. Syntheses were carried out by published methods, and each complex was checked by chemical analysis and thin layer chromatography. The complexes were shown to be d6 strong field systems by magnetic susceptibility measurements performed at room temperature in air.

Room temperature absorption spectra in the visible and near-ultraviolet were measured in solvents of different polarities (H₂O, MeOH, CH₃CN, DMF, CHCl₃) and solvent shifts of the band maxima of 0.3 to 3 kK were found. Low temperature (approximately 82-90°K) absorption spectra …

Molecular Luminescence From Turhenium, Osmium, And Terbium Chelates: 2°K To 300°K, Raymond William Harrigan

Chemistry and Chemical Biology ETDs

Two experimental spectroscopic investigations spanning the temperature range 300°K to 2°K were carried out on molecular complexes. The nature of charge-transfer phenomena in transition-metal chelates was studied extensively, and the thermal quenching of the luminescence of terbium (III) chelates was briefly investigated. The experimental methods employed were absorption and luminescence spectroscopy including photoflash excitation for studying transient luminescence decays. Measurements were performed on three osmium and three ruthenium complexes, all containing bidentate or tridentate heterocyclic aromatics as ligands. The compounds were studied in rigid solvent glasses, in poly(methyl methacrylate) (PMM), in an isomorphic host of tris(2, 2'-bipyridine)zinc(II) sulfate, and in …

The Synthesis Of Some New Azabenzo[A]Pyrene And Monomethyl Azabenzo[A]Pyrene Derivatives, Richard E. Phillips

Chemistry and Chemical Biology ETDs

The synthesis of six new azabenzo[a]pyrenes was undertaken in order that the carcinogenic and carcinostatic properties of these com­pounds might be tested. The compounds thus synthesized were 4-aza­ benzo[a]pyrene (1), 5-methyl-4-azabenzo[a]pyrene (2), 12-azabenzo[a]­pyrene (3), 11-methyl-12-azabenzo [a]pyrene (4),5 -azabenzo [a]pyrene (5), and 4-methy1-5-azabenzo[a]pyrene (6).

Compounds 1 and 2 were prepared from the intermediate 4-keto-1,2,3,4-tctrahydrochrysene. The azine from this ketone was dehydro­genated and the resulting aromatic amine was both formylated and acetylated. The amides were cyclized with polyphosphoric acid in a Bischler-Napieralski cyclodchydration giving fair yields of 1 and 2. The synthesis of compounds 3 and 4 was carried out in a …

Paths Of Energy Degradation In Transition Metal Complexes, James N. Demas

Chemistry and Chemical Biology ETDs

To elucidate the paths and rates of energy degradation in transition-metal complexes following photoexcitation, a comprehensive experimental study was carried out on a total of fourteen complexes of Ru(II), Os(II), Ir(III), and Rh(III). Photoluminescence lifetimes, spectra, wavelength dependences of the quantum yields, and absolute quantum yields were determined. The complexes all contained organic ligands—pyridine, 2, 2’bypyridine, 2, 2’ 2”-terpyridine, and 1, 10-phenanthroline. The ruthenium, osmium, and iridium complexes all exhibited charge transfer (CT) phosphorescences with quantum yields of 1-60% and lifetimes of 0.6-11 µsec in an alcoholic glass at 77°K. The rhodium complexes gave d-d* phosphorescences with yields in the …

Thermodynamics Of Proton Ionization In Dilute Aqueous Solution At 25°, Ernest J. Baca Jr.

Chemistry and Chemical Biology ETDs

This dissertation consists of four studies and is divided into five parts. Part I contains a description of the calculations and equipment used for these four studies.

Part II is a study of tris(hydroxymethyl)nminomethane (THAM) for use as a standard in solution calorimetry. The heat of solution of THAM in 0.100 M HCL was determined at 25°.

Part III is a study of the thermodynamics of proton ionization

from some unsaturated, five membered, nitrogen ring compounds in dilute aqueous solution at 25°. Values of deltaK, pK and deltaS are reported for 1,2,3-triazole, benzotriazole, 4,5-dibromo-1,2,3-triazole, 1-phenyl- 5-methyl-1, 2, 3-triazole-4-carboxylic acid, …

Spectroscopic Studies Of Complexes Of Rhodium (Iii) And Iridium (Iii), Dean H. W. Carstens

Chemistry and Chemical Biology ETDs

A comprehensive experimental and theoretical study of complex compounds of two d6 transition metal ions, rhodium(III) and iridium(III), was made to characterize the electronic transitions responsible for the various bands seen in the absorption and emission spectra and to determine the dependence of the energies of the excited states of a complex ion on the nature of the ligands and the central metal ion. All the complex compounds contained organic ligands—pyridine, 2,2’-bipyridine, or l,l0-phenanthroline—in the principal coordination sphere. Most also had halide ions bonded directly to the central ion. An ancillary study was made of 2,2’,2’’-terpyridine complexes of two d10 …

Liquid Scintillators. The Decomposition Of 2, 5-Diphenyloxazole In Ultraviolet Light. A Thin Layer Chromatography Study, John W. Hustler

Chemistry and Chemical Biology ETDs

A study has been initiated in order to understand more completely the manner in which a model organic scintil­lator decomposes in ultraviolet light. The compound, 2,5-diphenyloxazole (PPO), was dissolved in toluene in quartz vials and irradiated with ultraviolet light for various intervals of time. Both. vacuum-dried and untreated samples of PPO \·1ere subjected to UV excitation in sodium-dried and water-saturated solutions of toluene. The effect of passing oxygen and nitrogen through the solutions was also studied with the confirmation that dissolved oxygen and water accelerated the decomposition leading to the formation above the meniscus of the vial of a white …

The Chemical Behaviour Of Iodine At Low Concentrations In Strongly Acidic Solutions, Howard Allen Boyd Jr.

Chemistry and Chemical Biology ETDs

Radioactive tracers have been used extensively to investigate the behavior of substances at concentration too low to be detected by ordinary chemical or instrumental methods (1). Some elements exist only as short lived isotopes, and their chemistry is known only

in terms of their behavior at low concentrations, Other elements that have stable or long lived isotopes may be studied at low con­centrations by the use of suitable tracers, usually carrier-free radioisotopes when they are available,

A Study Of V(Iii) - V(Iv) And Ti(Iii) - Ti (Iv) Isotopic Exchange Reactions In Acid Solutions, Charles J. Orth

Chemistry and Chemical Biology ETDs

The subject of this dissertation is primarily the mechanisms and kinetics ot V(III) - V(IV) and Ti(III) - Ti(IV) electron exchange reactions in homogeneous solutions. The electron exchange process is a form of oxidation-reduction or electron transfer reaction where there is no net chemical change, i.e., the concentrations of the chemical species remain unchanged. In such cases there is a continuous exchange of electrons between a reduced and an oxidized form of the same element, such as between Fe(II) - Fe(III), V(III) - V(IV) or Tl(I) - Tl(III). The first two pairs involve one-electron changes while the thallium pair involves …

Studies On 4-Hydroxycoumarin Anticoagulants Part I: The Reversible Removal Of Carbon 2 Of 3-Substituted-4-Hydroxycoumarins Part Ii: The Synthesis And Urinary Excretion Rates Of The Enantiomers Of Warfarin-4-14c And Marcumar-2-14c, Lloyd Allen Goding

Chemistry and Chemical Biology ETDs

The hydrolytic removal and subsequent reinsertion of carbon 2 of a series of 3-substituted-4-hydroxycoumarins has been accomplished. The removal of carbon 2 presents an effective synthetic route to o-hydroxyketones with complex side chains. o-Hydroxyketones when condensed with alkyl carbonates gave good yields of 4-hydroxycoumarins. When this was carried out with ethyl carbonate-carbonyl-¹⁴C a radio label was inserted in position 2. It was shown that this decarboxylation-carboxylation cycle did not involve racemization of an optically active α-carbon on a side chain in position 3. This method was used to prepare the enantiomers of Marcumar-2-¹⁴C(3-α-ethyl-benzyl-4-hydroxycoumarin). The enantiomers of …

The Synthesis Of 5- And 8-Dialhylamino-Alkylaminopyrido [2,3-D] Pyridazines As Potential Antimalarial Agents, William M. Rich

Chemistry and Chemical Biology ETDs

The appearance of strains of malaria resistant to most of the synthetic antimalarial agents has prompted the investigation of new compounds for antimalarial activity. The structural similarities of the nucleus of pyrido [2,3-d] pyridazine to pteridine as well as to the known quinoline antimalarials suggested the possibility of development of potential chemotherapeutic agents based on the ring system.

A series of 5,8 substituted pyrido [2,3-d] pyridazines were prepared in which one substituent was a dialkylaminoalkylamino group and the other substituent either a chloro, ethoxy, or hydroxy group. Ultraviolet, infrared, and nuclear magnetic resonance spectra were reported for all compounds. Structures …

The Approximate Scf Lcao-Mo With Cndo Theory And Electronic Structures Of N-Heterocyclic Benzene Analogues, Jay Jea-Yong Rhee

Chemistry and Chemical Biology ETDs

The approximate MO theory in this study expIicitly refers to the Pople molecular orbitaI treatment. This consists of complete neglect of differential overlap (CNOO) in the self-consistent field treatment of the molecular orbitals, analogous to the Hartree-Fock treatment of atomic systems, which are constructed as Iinear combinations of atomic orbitals (LCAO). Furthermore, the only orbital functions considered in a basis set are those for the valence electrons and the atomic orbitals are Slater-type orbitals. The major investigation of this study is to apply this approximate MO theory to the series of nitrogen heterocyclic benzene analogues. The quantities that have been …

A Study Of The Synthesis And Reactions Of Condensed Pyriadazines, Lorraine Marie Distefano

Chemistry and Chemical Biology ETDs

A special interest in a nitramine rearrangement prompted the preparation of 1,4-diaminopyridazino [4,5-d] pyridazine and the nitration of this compound. Several reactions of the intermediates, which were synthesized en route to 1,4-diaminopyridazino [4,5-d] pyridazine, were studied. Strong evidence for the existence of keto-enol tautomerism was found in the case of 1,4-dihydroxypyridazino [4,5-d] pyridazine and its derivatives.

Some reactions of 5, 8-dichloropyrazino [2,3-d] pyridazine were studied with particular interest in the nucleophilic displacement of azides and in the nitration of 5,8-dianilinopyrazino [2,3-d] pyridazine.

The nitration of diaminophthalazine was also attempted in order to perform an acid catalyzed nitramine rearrangement from one …

Some Observations On The Chemical Behavior Of Carrier-Free Iodine-131 And Dilute Carrier Iodine0127, Manning S. Reynolds

Chemistry and Chemical Biology ETDs

Unexpected behavior by very small amounts of iodine has been noted by biochemical, medical, and ecological workers. It also has been shown that mild oxidation of carrier-free iodide-131 produced previously unknown species of iodine compounds. It was of interest to determine whether such species also result from the reduction of iodate.

While studying the formation of carrier-free iodate-131 by perchloric acid oxidation of iodide-131 at elevated temperatures, it was found that the acid is not directly responsible for the formation of iodate. Instead, the oxidation is accomplished by a volatile material (thought to be chlorine dioxide) formed only in perchloric …

The Synthesis Of Pyridazines, Cinnolines, Tetrazines, Tetrazapyrenes And Related Nitrogen Heterocycles, William D. Guither

Chemistry and Chemical Biology ETDs

There are many examples of nitro-substituted aromatic compounds, and of these the compounds in the benzene series have been most extensively studied. Nitro groups attached to an aromatic ring vary in reactivity toward nucleophilic displacement. For example, when two nitro groups are ortho or para to each other, one may be substituted with varying ease depending on the other substituents present. Nitro groups which are meta to one another are generally not subject to nucleophilic displacement. The mobility or ease of displacement of a nitro group by a nucleophile may be increased by introduction of other groups into the ring, …

The Cleavage Of Diborane By Tetra (Dimethylamino)Diboron And The Preparation Of Some Dihale (1, 10-Phenanthroline)Boron(Iii) Cations, Jack D. Cummins

Chemistry and Chemical Biology ETDs

Boron hydrides were first described and characterized by Stock (1). His early work has led to the proposal of about twenty new, distinctly identifiable hydrides (2). Of the proposed hydrides, it has been established that diborane-6 (B2H6), tetraborane-10 (B4H10), and nonaborane-15 (B9H15) contain bridged BH2 groups in the boron hydride framework (2,3,4,5,6,7,8,9). The proposed structures for these compounds is shown in fig. 1 (2,10).

Liquid Scintillators. The Stability Of Organic Scintillator Solutes Toward Ultra-Violet Radiation. The Photooxidation Of 2, 5-Diphenyloxazole, Harold A. Mackay

Chemistry and Chemical Biology ETDs

An insight has been gained concerning the stability of organic scintillator solutes in toluene on exposure to ultraviolet light while in the presence of oxygen and water. Oxygen and water, from either solute or solvent, not only function as quenchers but may continue to react with the solute molecule via a photooxidation process. Removal of these materials from the 2, 5-diphenyloxazole toluene system resulted in a marked improvement in stability of the system on exposure to ultraviolet light. The choice of scintillator solute, in addition to water and oxygen, and the time of ultraviolet irradiation, has a pronounced effect on …

Polarographic Investigation Of Several Tetrakis 1, 3-Diketone Europium Chelates In Acetonitrile, Samuel Lee Jeanjaquet

Chemistry and Chemical Biology ETDs

This study is concerned with the polarographic behavior of several tetrakis 1, 3-diketone chelates of europium and of the 1, 3-diketone ligands in acetonitrile. Such a study should reveal the following: (a) whether the europium (III) in the complexes is reduced directly to the metal, or if reduction to europium (II) takes place followed by reduction to the metal; (b) whether ligands are released during the reduction step(s) and if so, how many; (c) whether the polarographic behavior is such that dissociation constants of the complexes or complex ions can be determined by measuring the shift in half-wave potential as …

Some 2-Aryl-6-Phenylindenes, 2-Aryl-3-Methyl-6-Phenylindenes, 2-Aryl-3, 4-Dihydro-6-Phenylnaphthalenes, And 2-Aryl-3, 4-Dihydro-1-Methyl-6-Phenylnaphthalenes As Liquid Scintillators: The Steric Effects Of A Methyl Group, David Webster Holty

Chemistry and Chemical Biology ETDs

Liquid Solution Scintillator Systems1. Absorption and emission spectra of organic molecules arise from energy transitions within the molecule. Quantization of energy dictates that the energy levels in molecules will be specific and characteristic distances apart. The simplest description of the electronic energy levels in a molecule starts with "ground state" and includes "excited state #1” and so forth; this simple description allows only for the electronic excitation. In practice each electronic energy level is split into sublevels by other energetic transitions in the molecule, such as vibrations and rotations (Figure la).

Liquid Scintillators: Some 3-Aryl-L,2-Dihydronaphthalenes, 3-Aryl-1,2-Dihydro-4-Methylnaphthalenes, 3-Aryl-1,2-Dihydrophenanthrenes And 3-Aryl-1,2-Dihydro-4-Methylphenanthrenes: Steric Effects Of The Methyl Group, Lavinel G. Ionescu

Chemistry and Chemical Biology ETDs

There are two methods commonly employed for the measurement of radiation: the ionization chambers, such as the various types of Geiger­Mliller tubes, and the scintillation counters.

The Synthesis Of Condensed Pyridazines And Related Nitrogen Heterocycles As Potential Anticancer Agents, G. Anne Gerhardt

Chemistry and Chemical Biology ETDs

The antitumor activity found in such ring systems as purine (I), 8 - azapurine (II), pyrazolo[3, 4- d]pyrimidine (Ill) and pteridine (VI) prompted the preparation of substituted benzimidazoles, ν-triazolo­[4, 5-c]- (V), imidazo[4, 5-d]- (IV), pyrazino[2, 3-c]- (VII) and pyrazino[2, 3-d]- (VIII) pyridazines.

Intramolecular Spin-Orbit Coupling In Naphthalene Analogs, Francis Elliott Shoup Iii

Chemistry and Chemical Biology ETDs

The objective of this study was to gain additional insight into the phenomenon of spin-orbit coupling in molecules by examining the intramolecular mechanisms responsible for the phosphorescence of certain types of molecules. Spectrocopic investigations of a series of aromatic hydrocarbons, aromatic heterocyclics, and some of their halogen derivatives are reported. Experimental measurements included absorption spectra, total emission spectra, polarized emission spectra, obtained by the method of photoselection, and radiative lifetimes. It was found that chlorine substitution in naphthalene, quinoline, and quinoxaline has the effect of enhancing the transition probability for radiative transitions from the B_lu component of the ^{3 …}

Crystal Field Splitting In Rare Earth Chelates, Walter George Perkins

Chemistry and Chemical Biology ETDs

Investigations of ligand field effects in the spectra of trisdibenzoyl­methide, trisbenzoylacetonate, and trisacetylacctonatc chelates of trivalent ytterbium and thulium are reported. Chelate absorption and luminescence spectra corresponding to intra-4f electronic transitions exhibit line split­tings similar in magnitude to the crystal field splitting observed in the spectra of inorganic complexes of the rare earth ions.

Absorption spectra of carbon tetrachloride solutions of all the che­lates studied were measured in the visible and near infrared regions. Each ytterbium chelate exhibits an absorption band at 9800A, consisting of three well-resolved peaks. Thulium intra-4f absorption bands appear at 4700A, 6800A, 8000A, 12000A, and 17000A. …

The Radiochemical Purification Of Europium And A Study Of The Nuclear Properties Of Eu157, Eu158 And Eu159, William Richard Daniels

Chemistry and Chemical Biology ETDs

Chemical procedures have been developed for the rapid preparation of radiochemically pure europium sources from rare earth mixtures and from fission products. Unpurified mixtures of the mono- and dirp(l,1,3,3- tetramethylbutyl)phenyl 1 esters of orthophosphoric acid are used to ex­tract rare ei1arths in the (III) oxidation state away from europium in the (II) oxidation state. Europium sources can be prepared in about 30 min-11tes.

A slow􀀼r chemical procedure for the preparation of europium sources which are both radiochemically pure and mass free has also been developed. Di(2-ethylhEtxyl) orthophosphoric acid is used to separate europium from yttrium, which has a high fission …

Potential Diuretic Agents:-The Synthesis Of 4, 7-Disubstituted Derivatives Of 2-Phenylimidazo [4, 5-D]Pyridazine, Miriam P. Malm

Chemistry and Chemical Biology ETDs

"The maintenance of the water balance of an organism is of prime importance for its physiologic well-being." (1) Water, which composes approximately two-thirds of the entire human body weight, is the fluid in which all vital chemical reactions occur. A loss of 25 percent of body water usually proves fatal. The inherent physical and chemical properties of water render it as the ideal fluid to meet the physiological demands of the organism.