Chemistry Commons^™

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 …

The Control Of Algae, G R W Meadly

Journal of the Department of Agriculture, Western Australia, Series 4

CONDITIONS in areas of still, stored water in Western Australia can easily become ideal for the development of algae and control measures may become necessary in farm dams and swimming pools.

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 …

The Vapor-Liquid And Liquid-Liquid Phase Equilibria For The Partially Miscible System Methanol-Cyclohexane, Richard A. Christman

Masters Theses

By use of techniques of previous workers for determining liquid-liquid equilibrium and through the use of a circulation still, the complete phase diagram for the partially miscible system, methanol-cyclohexane, was determined. Tile accuracy of earlier liquid-liquid phase data was not improved upon although it was closely approximated. The critical solution temperature was found to be 46.4 degrees C., which is within the range of temperatures reported in earlier measurements.

Activity coefficients of methanol and cyclohexane were calculated from the phase boundaries of the boiling point diagram determined in the present investigation. These activity coefficients were in agreement with the Gibbs-Duhem …

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 Thermal Conductivity Of Liquid Helium 4 And Liquid Helium 3., Jerry F. Kerrisk

Chemistry and Chemical Biology ETDs

The thermal conductivity of liquid He4 (helium I region) has been measured between 1.77 K and 3.95 K, and the thermal conductivity of liquid He3 has been measured between 1.5K and 3.95K, both at pressures up to 34 atm. With He4, special attention was given to the vicinity of the lambda-transition, where data were taken as close as 10^-4 K to the transition. With He3, the critical region was given special attention. Data were taken within 10^-2 K of the critical temperature. The thermal conductivity of He4 and He3 gas at low pressure has also been measured between 1.5 K …

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 …

Catalytic Decomposition Of Hydrogen Peroxide By Manganese-Doped Magnesium Hydroxide, Nabih Philobbos Kelada

Archived Theses and Dissertations

No abstract provided.

The Function And Use Of Sulphur Dioxide In West Australian Winemaking, D Mann

Journal of the Department of Agriculture, Western Australia, Series 4

THE judicious use of sulphur dioxide is perhaps the most important of the fundamentals of winemaking in a hot climate.

Western Australia's vintage, centred in the Swan Valley just a few miles north-east of Perth, is subjected to some of the highest summer temperatures experienced by a quality wine producing district.

In this environment, it is important to make good use of sulphur dioxide to avoid wine spoilage.

Mathematics Of The Variation And Mole Ratio Methods Of Complex Determination, James O. Wear

Journal of the Arkansas Academy of Science

No abstract provided.

Properties And Structure Of Some Chalcogenide Glasses, Amin Ismail Amin Abdel-Latif

Archived Theses and Dissertations

No abstract provided.

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 …

Resonance Absorption Of P-Benzosemiquinone In The Zeeman Region, Juana Vivó Acrivos

Faculty Publications, Chemistry

No abstract provided.

The Effect Of Charged Interfaces On The Ionic Distribution In Solution, Myron Elliot Feinstein

Dissertations, Theses, and Capstone Projects

No abstract provided.

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 …

Spin-Resonance Transitions Of Free Radicals In The Zeeman Region, Juana Vivó Acrivos

Faculty Publications, Chemistry

No abstract provided.

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.

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).

Water Chemistry Survey Of Boulder Basin, Lake Mead, P. R. Tramutt, Bureau Of Reclamation

Publications (WR)

The survey results indicate that the impoundment of water behind Hoover Dam has not adversely affected the dissolved oxygen (DO) content and that water quality and DO content were uniform regardless of depth. The study made in April-May 1964 will provide water quality data of Lake Mead prior to releases from Lake Powell as a basis for evaluating Lake Powell's effect on water quality and limnology of Lake Mead. The performance of a DO analyzer was tested and found unsatisfactory at depths below 150 ft. Parameters tested by standard chemical analyses of water samples in the Denver Laboratory and by …