Chemistry Commons^™

Synthesis Of 4, 7-Disubstituted Derivatives Of Imidazo-[4,5-D]-Pyridazine And Related Compounds, William Seese

Chemistry and Chemical Biology ETDs

When this study was contemplated, no imidazo [4,5-d] pyridazines had been reported in the literature. Compounds of special interest due to their possible antitumor activity were the 4,7-dimercapoto-, the 4,7-diamino-, the 4-mercapto-, and the 4-aminoimidazo [4,5-d] pyridazines together with unsubstituted imidazo [4,5-d] pyridazine. Key intermediates in the preparation of substituted amines in the ring system were the 4-chloro-, and the 4,7-dichloro- derivatives.

The Magnesium-Hydrogen System, J. Frederick Stampfer Jr.

Chemistry and Chemical Biology ETDs

The motivating factor for this investigation of the magnesium-hydrogen system was the recent interest in the hydride of beryllium. Although beryllium hydride has been prepared by the pyrolysis of di-t-butylberyllium, no evidence for the direct union of beryllium and hydrogen has been reported. It was thought that an examination of the reaction between magnesium and hydrogen and determination of the thermodynamic relations involved might have a bearing on this phenomenon. Also, the properties of magnesium hydride are interesting from an over-all periodic table viewpoint. The hydrides of beryllium and magnesium are usually considered to be intermediary between the saline, or …

The Extraction Of Scandium, Yttrium, And Lanthanum Using Various Monoalkyl Orthophosphoric Acids, Clarence Gerald Warren

Chemistry and Chemical Biology ETDs

The separation of lanthanum, yttrium, and the rare earth elements from their ores has been a challenge to the chemist for many years. The similarity in chemical properties has made their separation a problem of extraordinary difficulty. Fractional crystallization has been the classical method utilized in the past, although individual elements have been isolated by oxidation or reduction to other than the tripositive oxidation state (1). Recently ion exchange and solvent extraction methods have become more important as a means of separation of these elements. Both of these techniques depend upon fractional differences in the distribution of compounds or ions …

Absorption Of Antimony(Iii) And Indium From Anhydrous Acetic Acid By Ion Exchange Resins, Robert Tor Lofberg

Chemistry and Chemical Biology ETDs

Organic ion exchange resins are a comparatively recent development. In 1935 Adams and Holmes prepared the first ion exchange resin by polymerizing polyhydric phenols with formaldehyde. The condensation product exhibited definite reversible cation exchange properties. The success of this experiment led them to the development of the first anion exchange resin which was prepared by the polymerization of phenylenediamine with formaldehyde. The publication of these experiments inspired many similar investigations leading directly to the manufacture of the numerous ion exchange resins now commercially available.

The Synthesis Of Some Methyl Substituted 3,4-Benzpyrenes, Jules L. Adelfang

Chemistry and Chemical Biology ETDs

3,4-Benzpyrene (I), a highly carcinogenic hydrocarbon was first isolated from coal tar in 1933 by Cook, Hewett, and Hieger. Interest in the relationship of structure to carcinogenic activity and correlation of physical properties with carcinogenic potency led to the synthesis of several monomethyl 3,4-benzpyrenes during the decade following the isolation of the parent hydrocarbon. Detailed reviews concerned with the various phases of this research have been prepared. Recently the synthesis of the 1-^2, 7-^3, 8-^(2,5), and 10-^4 methyl-3,4-benzpyrenes completed the series of reported monomethyl derivaives.

The Chemical Behavior Of Iodine At Tracer Concentrations, Henry Morris Eiland

Chemistry and Chemical Biology ETDs

Radio-chemistry was introduced as a separate branch of chemistry by Pierre and Marie Curie in 1898. The first radio-chemical process consisted of the separation and identification of the new element Polonium from the uranium ores pitchblende and chalcalite. It is significant that this process involved an amount of material so small that it could be detected only by its intense radioactivity. In the last half-century radio-chemistry has developed into a field of ever increasing diversification.

A Study Of The Density And Molecular Species Of Polonium And Tellurium Vapor, Angelo L. Giorgi

Chemistry and Chemical Biology ETDs

The purpose of this investigation was to determine the nature of the species of polonium and tellurium in equilibrium in the vapor phase at temperatures ranging from 422 degrees to 1013 degrees C. for polonium and from 512 degrees to 880 degrees C. for tellurium. Such information was based on measurements of the variation of vapor pressure and vapor density with temperature. The results of this investigation suggest that both polonium and tellurium exist as diatomic molecules in the vapor phase over the aforementioned temperature ranges.

Studies Of The Chemistry Of Systems Involving Water, Hydrogen Peroxide And Plutonium (Iv) Nitrate In Tri-N-Butyl Phosphate, Lawrence J. Mullins Jr.

Chemistry and Chemical Biology ETDs

The reaction of tri-n-butyl phosphate (TBP), with water and hydrogen peroxide is studied by means of distribution experiments. The solubility of water in TBP-hexane, at low TBP concentrations, is consistent with the premise that H₂O•TBP is the principal solvate species formed at low hydrogen peroxide concentrations. The distribution data at high hydrogen peroxide concentrations indicate that another species such as H₂O₂•TBP is also present.

A Radiochemical Investigation Of Short-Lived Selenium And Bromine Fission Products, James Edward Sattizahn Jr

Chemistry and Chemical Biology ETDs

From a sample of uranium bombarded with neutrons, Hahn and Strassmann, in 1939, separated four radioactive products which followed alkaline earth chemistry and were therefore tentatively attributed to isotope of radium. Each of these products decayed to a daughter activity which could be precipitated along with lanthanum; the daughter activities were then assumed to be isotopes of actinium. Subsequently, by accepted methods of fractional crystallization and precipitation, the "radium" and "actinium" isotopes were identified unequivocally as isotopes of barium and lanthanum, respectively. Within a relatively short time there were found more such radioactive products, which were identified as isotopes of …

Behavior Of Indium At Tracer Concentrations, Katheryn L. Lawson

Chemistry and Chemical Biology ETDs

The increase in number and availability of radioisotopes that can be produced in the carrier-free state has offered practical means of investigating the chemical behavior of substances at extremely low concentrations. The working region of concentrations, which may extend to less than 10^-14 molar, is generally fixed only by the half-life of the radio-element and the nature of the radiation.

The Exchange Of Chlorine Between Hydrogen Chloride And Acetyl Chloride In The Vapor Phase, Warren J. Niell

Chemistry and Chemical Biology ETDs

The aim of chemical kinetics is to predict the rates of chemical reactions, to determine the factors influencing the reaction rate, and to postulate a suitable reaction mechanism.

The Chemical Effects Of Gamma Radiation On Halogenated Methanes, Clifford G. Shultz

Chemistry and Chemical Biology ETDs

At its inception, the present work was to consist of testing a number of halogenated organic compounds for sensitivity to radiation. Some of the compounds which showed a relatively high sensitivity to radiation were to be investigated more thoroughly with a view toward a) the development of a sensitive radiation detection device and b) elucidation of the reactions involved in the radiolytic decomposition of the compounds. Some screening had already been done and several systems involving chloroform, bromoform and carbon tetrachloride had been investigated and their results reported. The experiments on the chloroform- and bromoform- crystal violet systems showed a …

The Synthesis Of 7-Methyl-3,4-Benzpyrene, 6,7-Dimethyl-3,4-Benzpyrene, 10-Methyl-3,4-Benzpyrene And 7,10-Dimethyl-3,4-Benzpyrene, Joseph Leonard Comp Jr.

Chemistry and Chemical Biology ETDs

Interest in carcinogenic compounds began to develop when a form of cancer was found occurring in chimney sweeps in 1775. Skin cancer was found among workers in tar industries in 1875, and in 1887 workers in cotton spinning industries were known to have cancer which was attributed to contact with lubricating oils. Girls who painted the luminous dials of watches contracted cancer from exposure to the radioactive paint, and men who worked with B-naphthylamine developed bladder cancer. Many other cases of occupational cancer were reported before a systematic study of carcinogenic substances was begun. Early attempts to produce cancer in …

A Study Of Isotopic Exchange Between Potassium Iodide And Benzyl Iodide. Solvent Effects, Joseph A. Leary

Chemistry and Chemical Biology ETDs

The kinetics of the isotopic exchange reaction between potassium iodide and benzyl iodide in alcoholic solution has been studied thoroughly by Stillson. It was reported that the reaction was much faster in ethanol-acetone mixtures than in absolute ethanol. However, it was not possible to determine whether this was due to acceleration of the reaction by acetone, or to inhibition by ethanol.

The purpose of this investigation was to elucidate further the effect of various solvents on the same exchange reaction. The isotopic exchange reaction between potassium iodide and p-nitrobenzyl iodide was also studied, because it had been investigated in alcoholic …

Coprecipitation Of The Transuranium Elements With The Rare Earths Coprecipitation Of Americium With Lanthanum Oxalate, John A. Hermann

Chemistry and Chemical Biology ETDs

Coprecipitation is a process whereby a substance soluble by itself is "carried" with an insoluble crystalline precipitate. As used here, coprecipitation applies to the "carrying" of a tracer by a precipitate formed in the presence of the tracer. The phenomenon is important in analytical chemistry¹, in the problem of impurities in precipitates; in radiochemistry^2,3, in the separation of radioactive tracers originally present in very low concentrations; and in general, whenever a solid is separated from its mother liquid by precipitation.

The Synthesis Of 1-Methyl-3,4-Benzpyrene, 8-Methyl-3,4-Benzpyrene And 1,8-Dimethyl-3,4-Benzpyrene, William Carter Doyle

Chemistry and Chemical Biology ETDs

The search for the carcinogenic factor present in crude oil tar fractions was begun around 1915. With the observation that the high-boiling, most carcinogenic fractions exhibited fluorescence spectra similar to those of many polycyclic aromatic hydrocarbons, several synthetic hydrocarbons were tested (1) on mice by skin painting techniques. Tumors were produced by 1,2,5,6-dibenzanthracene (I), 3'-methyl-1,2,5,6-dibenzanthracene (II) and 6-isopropyl-1,2-benzanthracene (III). One of the most widely used synthetic hydrocarbon carcinogens at the present is 1,2,5,6-dibenzanthracene.

The Decomposition Of Solid Barium Nitrate By Gamma Rays, Lawrence E. Lamar

Chemistry and Chemical Biology ETDs

Very little work has been done on the chemical effects produced during the irradiation of solid materials. Although some research has been reported concerning the action of ultraviolet light on solid nitrates, most of the information in the literature is based upon the use of nuclear radiations.

Two types of reaction mechanisms have been proposed by previous authors. The direct decomposition of the metal nitrate to give the nitrate and oxygen was concluded from measurements of optical absorption. The ionization of nitrate ion to yield mononitrogen trioxide which could disassociate after capture of an electron was also suggested. The mononitrogen …

The Synthesis Of 2-Methyl-3, 4-Benzpyrene And 2, 8-Dimethyl-3, 4-Benzpyrene., James W. Patton

Chemistry and Chemical Biology ETDs

In 1933 Cook, Hewett and Hieger (1) isolated a carcinogenic hydrocarbon from coal tar thought to be 3,4-benzpyrene (I).

The Exchange Of Antimony Between Antimony Trichloride And Antimony Pentachloride In Carbon Tetrachloride Solution, Franklin Brett Barker

Chemistry and Chemical Biology ETDs

In the investigation of any chemical reaction, the main points of interest are the conditions of equilibrium, the rate at which equilibrium is approached, and the mechanisms by which the reaction occurs. The first of these is determined by the standard free energy change, a thermodynamic quantity which depends only upon the initial and final states of the system. However, two reactions having the same value of the standard free energy change may approach equilibrium at radically different rates, one being practically instantaneous and the other almost infinitely slow. The field of chemical kinetics is concerned with the study of …

Exchange Reactions Of The Transuranium Elements Section 1. Am(Iii)-Am(V)-Am(Vi), Am(Iii)-Am(V), And Am(V)-Am(Vi), Thomas K. Keenan

Chemistry and Chemical Biology ETDs

No exchange work prior to this dissertation has been reported on the Americium system. Neptunium exchange is presently being studied by J. C. Hindman and co-workers at the Argonne National Laboratory, but has not been completely reported. Study of uranium exchange, which is still in an unsatisfactory state, has been limited to the U(IV)-(VI) exchange.

The Synthesis Of 10-Methyl-3, 4-Benzpyrene And 8,10-Dimethyl-3, 4-Benzpyrene, Jules Adelfang

Chemistry and Chemical Biology ETDs

In 1953 Cook, Hewett, and Rieger found a highly carcinogenic hydrocarbon in coal tar. By a variety of solvent extraction methods, fractional distillation, and crystallization several pure hydrocarbons were isolated from the crude pitch. Two new pentacyclic aromatic hydrocarbons were isolated and since only small quantities of them were available it was decided to ascertain their structures by synthesis instead of degradetive experiments. The hydrocarbon samples were obtained with great difficulty from two tons of crude pitch. The problem was simplified since ten of the possible fifteen pentacyclic hydrocarbons were known. From certain similarities of these hydrocarbons to perylene its …

An Investigation Of Some Changes In The Chemical Composition Of Arterial Tissue Which Correlate With The Development Of Arteriosclerosis, Richard Dee Strickland

Chemistry and Chemical Biology ETDs

Arteriosclerosis is one of the major health problems confronting people of middle and advanced age. The disorder, commonly called "hardening of the arteries", is a contributing factor in more deaths than any other ailment.

The profound alteration in the physical properties of arteries which comes about as a result of the sclerotic process suggests that equally important changes may take place in the chemical composition of the arterial tissue.

Studies In The Cinnoline Series, David B. Cox

Chemistry and Chemical Biology ETDs

Recent work by Castle and Kruse (16) has partially elucidated the range of reactivity of the chlorine atom in the compounds 4-chlorocinnoline and 4-chloro-6,7-dimethoxycinnoline. Condensations between the chlorinated cinnolines and certain phenylacetonitriles were found to proceed readily; however, condensations with compounds of the malonic ester type were unsuccessful. It was found that hydrolysis of the condensation product obtained from 4-chlorocinnoline and phenylacetontrile by hot 60% sulfuric acid caused decarboxylation of the intermediate acid, the final product being 4-benzylcinnoline. This compound has a formal resemblance to the basic ring structure of papaverine.

Chelation Of The Rare Earth Elements As A Function Of Ph Using Thenoyltrifluoroacetone, Hugh James Bronaugh

Chemistry and Chemical Biology ETDs

The rare Earth elements, or lanthanides, having atomic numbers 57 through 71 occupy only one space in the periodic chart of the elements. These fifteen elements, which have extraordinarily similar chemical and physical properties, are placed in group three of the periodic table, between barium of group two and hafnium of group four. This series of elements has been the subject of extensive study in the past. The development of atomic energy has significantly increased the interest in the rare earths in the past ten years.

A Study Of The Kinetics And The Free Radicals Involved In The Low-Pressure, Vapor-Phase Pyrolysis Of Toluene, Robert E. Williams

Chemistry and Chemical Biology ETDs

This research was undertaken to study the pyrolysis of toluene in the vapor phase.

Many pyrolytic reactions of toluene have been studied by others, but the difficulty of controlling the reactions and the complexity of the products have not allowed much successful application of the results. The present work was an endeavor to better understand the reaction mechanisms and the intermediates involved in pyrolysis.

Specifically, the problem was to study the discrepancies between the results reported by M. Szwarc and by Hein and Mesee.

The Separation Of Antimony 125 From Solutions Of Neutron Irradiated Tin Salts, Joseph D. Robinson

Chemistry and Chemical Biology ETDs

Because of the importance of high specific activities of radioactive species considerable experimental work has been done on the preparation of "carrier-free" tracers. In surveying the literature on the preparation of carrier-free antimony only one method was found. The method reported involves the deuteron bombardment of tin; solution of the target in agua regia; addition of cadmium carrier; precipitation of the cadmium as the sulfide which carries antimony, using oxalate ion to complex the tin; solution to the sulfides of cadmium and antimony in concentrated hydrochloric acid; distillation of tin from cadmium and antimony contained in in perchloric acid with …

Polargraphic Measurement Of Reaction Rates Of Diazonium Salts, Gregory W. Daues

Chemistry and Chemical Biology ETDs

If a colorimetric method is used for following the reactions by tracing the increase in dye concentration, only reactions which form soluble dyes can be studied. Gasometric techniques are limited in that a sample must be removed from the reaction vessel and the diazonium salt decomposed by means of a catalyst in order to measure the liberated nitrogen. The latter method of analysis lends itself more readily to studies of the rate of decomposition of diazonium salts under various conditions, such as, the presence of ultra-violet light or exposure to high temperatures.

The Kinetics Of The Exchange Between Diiodotyrosine And Iodine, Alfred H. Zeltzmann

Chemistry and Chemical Biology ETDs

The rate of exchange of iodine with diiodotyrosine in squamous solution was studied as a function of the concentrations of both reactants, of the pH, and of the temperature. The concentration of diiodotyrosine was varied from 0.0000475 to 0.01251 moles per liter and that of the iodine from 0.0000103 to 0.000395 moles per liter. The upper limits of concentration studied were determined by the solubilities of both the iodine and diiodotyrosine. The ratio of concentration of diiodotyrosine to that of iodine was varied from 227 to 0.5. the temperature was varied from 25.1 degrees C to 42.1 degrees C, and …

A Study Of The Exchange Between P-Nitrobenzyl Iodide And Iodide Ion In Alcoholic Solutions., E. Lee Purlee

Chemistry and Chemical Biology ETDs

The realm of this study embraces observation of the exchange of iodine and potassium iodide in absolute methanol, absolute ethanol and absolute n-propanol at temperatures of 30.9 °, 20.3 ° and 0.0 ° centigrade. The primary aims were to observe the effects of the p-nitro group upon the exchange rates in effects of the p-nitro group upon the exchange rates in the various solvents and to compare the results with those obtained for the benzyl iodide-iodide exchange.

Enrichment Of Tin Activity Through The Szilard-Chalmers Separation, Herta W. Spano

Chemistry and Chemical Biology ETDs

It was the purpose of this investigation to utilize the Szilard-Chalmers reaction in order to prepare tin solutions of high specific activity.

Tetraphenyl tin was chosen for the target compound. It is a white, crystalline solid of excellent thermal stability. No data have been reported in the literature on the rate of exchange between inorganic forms of tin and tetraphenyl tin but it seemed highly probable that this exchange would be very slow. Tetraphenyl tin is soluble in various organic solvents but insoluble in water, and this suggested solvent extraction as a possible means of separation of the activated tin …