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A Slatis-Siegbahn type beta ray spectrometer was modified by installation of a scintillation detector, and by the addition of a mechanism for automatically scanning and recording a beta spectrum at any desired rate. An analysis of pulse heights indicated that about 80% of incident 25 Kev. electrons could be detected with a background of 150 counts per minute. A study of activities arising from proton bombardments of rheniun and tungsten was made using the beta ray spectrometer in conjunction with a sodium iodide gamma spectrometer. [...]

Thesis (Ph. D.)--University of Wisconsin--Madison, 1966. / Typescript. Vita. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaves 127-132).

1. The compound [Co(CO)₄]₂ [Co(phth)₃] was prepared by a previously described method (15). It was found to be unstable in the dry state and in solution in various organic solvents. 2. The solubility of the compound in various organic compounds was determined. 3. Conductance measurements in benzaldehyde and acetophenone were made. The molar conductances obtained indicate that the compound is a true salt. 4. Transference measurements were made in an acetone solution. The concentrations were determined by making one or other of the cobalt atoms active. The results obtained are probably invalid because of exchange between the two cobalt atoms. 5. Exchange between the two cobalt atoms in [Co(CO)₄]₂ [Co(phth)₃] was studied, and no exchange was found under the conditions of the experiment. 6. The exchange between active, cobalt (11) ions and the cobalt phenanthrolene complex ion was studied. The exchange was found to be very rapid, reaching an equilibrium in a few minutes. 7. The exchange between active, cobalt metal and dicobalt octacarbonyl was studied, no exchange being found. / Science, Faculty of / Chemistry, Department of / Graduate

Nanosecond pulse radiolysis studies on the behaviour of ē aq at high concentrations as a preliminary to the investigation of ē aq* have shown that contrary to normal classical homogeneous kinetics the electron decays initially in a first order manner, moving into second order decay within about 100 nanoseconds after the electron pulse. Further investigations have shown that for a comparable time after the pulse the distribution of the absorbing species is not homogeneous thus rendering any classical kinetic interpretation invalid. Qualitative calculations on the duration of the inhomogeneity were performed and the experimental results are in reasonable agreement with their predictions, The first order decay that is observed is considered to be more than a random sequence of reactions and two possible models are tentatively proposed to account for these events. Comparisons are made between this work and others in which inhomogeneity undoubtedly accounts for the unusually fast bimolecular rate constants for the primary decay ē aq + ē aq → H₂ + 2OH ̄ aq The deuterated electron was investigated with similar conclusions. The rate constants evaluated from this work were: [ Formulas omitted ] and the bimolecular rate constant, determined in a homogeneous environment, is in good agreement with the accepted literature values for the probable reactions involving ē aq in our system. / Science, Faculty of / Chemistry, Department of / Graduate

The experimental work presented in this dissertation consists of two separate parts. Firstly, a study of the reaction of hydrated electrons with molecular nitrogen is reported. Secondly, the results of an investigation of the effects of Ƴ-radiation on the polar aprotic solvent, propylene carbonate; (a) in the glassy solid state at 77 °K, and (b) as a liquid at room temperature, are presented. Hydrated electrons were generated by Ƴ-radiolysis of aqueous solutions containing H₂ and 0H⁻ and also containing N₂ at concentrations up to 0.1 M (200 atm pressure). Significant yields of ammonia were obtained, but by completely eliminating the gas space above the solution it was shown that the majority of the NH₃ arose through "direct action" of the radiation on dissolved N₂. Although the hydrated electron is one of the most powerful and reactive reducing agents, it is unable to cause reduction fixation of molecular nitrogen. An upper limit of k₁<18 M⁻¹s⁻¹was estimated for the rate constant of the reduction reaction. Conversion of the hydrated electrons to H atoms in acid solution did not affect the ammonia yield, implying that H atoms are also unable to reduce nitrogen. In the glassy solid state at 77 °K, Ƴ-irradiation of propylene carbonate produced species identified as trapped electrons. They were characterised by a narrow [formula omitted], Gaussian shaped ESR line at g = 2.0028 and an optical absorption band with ʎmax∼ 370 nm . The electrons were unstable at 77 °K and decayed via a non-homogeneous process believed to be reaction with positive ions. Also formed by the Ƴ-radiation were four unidentified trapped radicals, all characterised by doublet ESR signals centered at g = 2.0023 and with hyperfine splittings of 42, 58, 83, and 124 G . Ultraviolet photolysis of the irradiated glasses at 77 °K produced new radicals identified as CO₃ , HCO and CH₃. The CO₃ radical gave a single ESR line at g∼2.015 and a broad visible optical absorption band with ʎmax∼600 nm. HCO was identified by its asymmetric doublet ESR signal with hyperfine splitting of about 130 G and a multi-line vibronic absorption spectrum in the 500 - 750 nm region. The methyl radicals were unstable in the matrix and were identified by their characteristic 1:3:3:1 quartet ESR spectrum with hyperfine splitting of about 21 G . Ƴ-radiolysis of liquid propylene carbonate at 25 °C produced H₂ , CO and CO₂ as the major gaseous "molecular" products with yields: GH₂= 0.75 ± 0.05, GCO = 1.2 ±0.1, and GCO₂ = 3.2 ±0.3. Methane was also produced via a secondary process involving methyl radicals with a yield: G(CH₄) = 0.20±0.02 . Scavenger experiments with N₂0, I₂, methanol and acid indicated that an anionic reducing species was formed by the radiation with a yield of GX - = 2.0±0.2 . This species was probably a solvated electron although the possibility of it being a reactive molecular anion could not be excluded on the basis of the steady state radiolysis data. A transient optical absorption at 630 nm was observed on pulse radiolysis of propylene carbonate with 3 nsec pulses of 0.5 MeV electrons. However, either solvated electrons or the C0₃⁻ radical ion could have been responsible for the absorbance. / Science, Faculty of / Chemistry, Department of / Graduate

This thesis reports pulse radiolysis investigations on the very early physicochemical and chemical events in the radiation chemistry of polar liquids, in particular liquid water, where transient absorptions due to the hydrated electron have been observed with lifetimes as short as ∼30 picoseconds. These studies were carried out using the novel technique of Cerenkov reabsorption spectroscopy, which in conjunction with an extremely high dose-rate electron accelerator (peak dose-rate = 1.8 x 10²⁸ eV cm⁻² sec⁻¹) yields information pertaining to subnanosecond radiation chemical events from measurements made with existing nanosecond technology. A critical evaluation of all experimental aspects of this newly developed technique, as well as a partial theoretical analysis of the relationships between the physical parameters and experimental observables, have both been performed in order to establish the validity of such pulse radiolysis studies. Kinetic effects in molar concentrations of hydrated electron scavengers and relative solvated electron yields in water and the alcohols, have been interpreted to suggest that the time-scale of charge neutralization in radiation chemistry is very much shorter than previously proposed, thus necessitating a modification of the existing description of subnanosecond events as contained in the spur diffusion model for radiation chemical yields. The primary reducing species in the radiolysis of formamide, a liquid of very high dielectric constant, was postulated as a negative ion, rather than a solvated electron; this negative ion being formed directly by solvent scavenging of thermalized electrons. With the availability of new spectral data for solvated electrons from this and other work, a revival of the earlier suggested spectral correlation with iodide ion C.T.T.S. spectra has been proposed, with many of the earlier discrepancies now removed. Finally, because absorption spectra are deduced from light emission measurements in the Cerenkov reabsorption technique, an added feature of this work was the possible observation of radiation-induced molecular luminescence from liquid water; however over the spectral range 200 nm - 850 nm the limiting 100 eV yield of such luminescence was ≤10⁻³ with a lifetime ≤ 2 nanoseconds. / Science, Faculty of / Chemistry, Department of / Graduate

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Thesis (Ph. D.)--University of Wisconsin--Madison, 1958. / Typescript. Abstracted in Dissertation abstracts, v. 19 (1959) no. 12, p. 3154-3155. Vita. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaves 209-213).