Thesis (Ph. D.)--University of Wisconsin--Madison, 1984. / Typescript. Vita. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references.

Thesis (Ph. D.)--University of Wisconsin--Madison, 1964. / Typescript. Vita. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaves 65-68).

Thesis (Ph. D.)--University of Wisconsin--Madison, 1984. / Typescript. Vita. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references.

Thesis (Ph. D.)--University of Wisconsin, 1967. / Typescript. Vita. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references.

No description available.

A new sensitive spectrophotometric method for the direct determination of Co²⁺ ion in the presence of excess Co(III) was developed. Using this method the primary quantum yields for the photochemical decomposition of potassium cobaltioxalate were determined at pH 3 and 0°C over a wide range of wavelengths. The values for the various mercury lines were found to be: 280 mu, .369; 302 mu, .329; 313 mu, .362; 334 mu, .279; 365 mu, .244; 405 mu, .108; 435 mu, .067; 578 mu, ≤ .00033. The quantum yield for cobaltous ion formation is twice the primary quantum yield. No dependence of the quantum yield on the cobaltioxalate concentration was detected. The results are expected to be essentially the same in neutral solution because the instability constant of cobaltioxalate is extremely small. Correlation of the quantum yields with the absorption spectrum showed that photoactivity is considerable both for the electron transfer peak (in the U.V.) and the first d - d band (in the blue spectral region). Gaussian extrapolation of the absorption bands shows that a constant level of photoactivity cannot be directly assigned to each band. Further treatment of the data indicates that the quantum yields can be represented as two different functions of the logarithm of the light energy which however cannot be directly related to the two different types of transitions. The results are finally explained on the basis of internal conversion between the d - d and charge transfer bands. / Science, Faculty of / Chemistry, Department of / Graduate

Previous research on the photolyses of ketene at 2700 A and 3650 A has shown that considerably different mechanisms are necessary to explain the experimental results. Exactly how the process of deactivation of the excited ketene molecule was affected by change in wavelength was not fully understood. It was felt that investigations of the primary quantum yields at intermediate wavelengths would be fruitful in obtaining a better understanding of the variation of reaction mechanism with wavelength. At 2700 A, using pure ketene, the only primary process is dissociation and therefore the primary quantum yield is unity, while at 3650 A dissociation occurs by way of an excited state which has a finite lifetime during which the excited ketene molecule may undergo collisional deactivation and internal conversion. At 3650 A therefore the primary quantum yield is much less than unity even at low pressure, and decreases with increasing pressure. This research has shown that in the case of ketene at 3130 A the primary quantum yield is approximately unity at low pressures, 20 mm., and decreases to 0.6 at one atmosphere. At 3340 A the primary quantum yield is approximately 0.7 at 26 mm. and 0.2 at 400 mm. and increases with increasing temperature. The dependence of primary quantum yield on pressure at 3130 A and 3340 A was anticipated and can be explained by almost the same mechanism as that proposed for 3650 A radiation. The amount of radiation absorbed during each run was very accurately measured and it was therefore possible to determine quantum yields to within ± 2% at 3130 A, and within ± 10% at 3340 A. For the photolysis at 3650 A the ratios of the rate constants of collisional deactivation and product formation and of internal conversion and product formation at 26° C are 4.6 x 10⁴ litres/mole and 28 respectively. At 3130 A and 37°C this research has shown these ratios to be 16.8 litres/mole and zero respectively, while at 3340 A the ratios are 1.64 x 10² litres/mole and 0.25 at 37°C and 0.99 x 10² and 0.1 at 100°C. / Science, Faculty of / Chemistry, Department of / Graduate

In order to extend the study of medium-sized ring compounds, cis,cis-cyclodeca-3,8-diene-l,6-dione was synthesized by known methods and photolyzed. By monitoring the photolysis by glpc and tlc, it was evident that the initial photochemical reaction of cis , cis-cyclodeca -3 ,8-diene-1,6-dione was photoisotnerization to cis , trans-cyclodeca-3,8-diene-1,6-dione, which then underwent intramolecular cycloaddition in a second photochemical step to give cis, anti, cis-tricyclo[5.3.0.0²,⁶]-decane-4,9-dione. To show that the observed photoproduct was formed primarily by a secondary photolytic reaction, the cis, trans-cyclodeca-3 ,8-diene-1,6-dione was photolyzed to give cis, anti, cis-tricyclo[5.3.0.0²,⁶] decane-4,9-dione as the only product. Further evidence in support of the two-step reaction hypothesis was obtained by a kinetic study of the cis, cis-cyc1odeca-3,8-diene-1,6-dione photolysis. Two plausible mechanistic routes for the above photolysis are discussed in terms of the observed intermediate. These mechanistic pathways are then compared to the routes established for other β,ɤ- unsaturated ketone photolyses. / Science, Faculty of / Chemistry, Department of / Graduate

Vibrationally excited oxygen with up to 15 quanta of energy has been produced in the flash photolysis of NO₂ . When the NO₂ was selectively photolysed such that only radiation below 4000 A° was admitted to the reaction vessel the highest level observed was reduced to v" = 11 which in terms of vibrational energy corresponds to the exothermicity of the reaction O + NO₂ —> NO + O₂ Relative population ratios for the successive vibrational levels v" = 6 to 11 were calculated for both the filtered and unfiltered photolysis of NO₂ using two independently calculated arrays of Franck-Condon Factors. In both cases the ratios showed that the population distribution was definitely non Boltzmann. in that the levels were almost equally populated. The distribution for the unfiltered experiments gave a pronounced dip at v" =11 indicating that the levels 12 ≤ v" ≤ 15 are formed by a second reaction. This reaction has been shown to be Q+ NO*₂—> O*₂ v" ≥12 +NO where the NO₂ is probably electronically excited. The adiabatic flash photolysis of both NO₂ and SO₂ has been investigated. These spectra show weakening of their banded structure up to 100 microseconds after the flash and then gradual strengthening until back to normal by 10 milliseconds. This effect is well known for SO₂ and has been postulated to be the result of the formation of a high temperature isomer of SO₂. Subsequently the postulated isomer had a transient spectrum in the vacuum ultraviolet assigned to it. We have found that the weakening of both the NO₂ and SO₂ banded structure is the result of temperature broadening. The spectrum assigned to the SO₂ isomer has been extended. It has also been produced from the flash photolysis of SO₂ under isothermal conditions showing that its assignment to a high temperature isomer is incorrect. From kinetic data this spectrum in the 1800 A° region and another the 1400 A° region has been tentatively identified as two triplet systems of SO. / Science, Faculty of / Chemistry, Department of / Graduate

Thesis (Ph.D.)--Bowling Green State University, 2005. / Document formatted into pages; contains xvi, 135 p. : ill. Includes bibliographical references.