Luminescence Studies: Luminescence of Aqueous Ionic Solutions; Temperature Dependence of the Phosphorescence of Phenanthene in Ethanol - Effects of Gases.
Date of Award
Doctor of Philosophy (PhD)
Part I. Luminescence of Aqueous Ionic Solutions. An anomolous luminescence of aqueous solutions of I('-), Br('-), OH('-) etc. is observed and appears to be characteristic of the solvent. The emission of a KBr solution is greatly reduced by purification of the KBr. However, upon addition of acids, this emission reappears. Since all of the ions involved are known to have charge transfer to solvent (CTTS) transitions, the luminescence is postulated to be due to the recombination of H(,3)O('+) and e('-). Hydroxide and hydrosulfide appear to be a special case and may be transferring a hydrogen atom to the water. Discussions of the hydronium radical and the triplet state of water are presented. Neither of these entities can account for the luminescence; however, an excited state complex between water and a hydrogen atom may be involved. Part II. Temperature Dependence of the Phosphorescence of Phenathrene in Ethanol--Effects of Gases. The effects of various gases upon the temperature dependence curves of intensity and lifetime of the phosphorescence of phenanthrene in ethanol are studied. A shift of both the glass transition region and crystal formation region for ethanol is observed when oxygen or nitrogen is added to the sample. Samples with other nonpolar gases (Ar and Ethane) added do not exhibit this shift. The effect for oxygen and nitrogen is explained by invoking hydrogen bond breaking by O(,2) and N(,2). A discussion of glass transition and hydrogen bond breaking studies is presented and found to support this suggestion. The work is extended to the melting curves of DNA, where a similar effect is observed.
Mathers, Terrence Lenoir, "Luminescence Studies: Luminescence of Aqueous Ionic Solutions; Temperature Dependence of the Phosphorescence of Phenanthene in Ethanol - Effects of Gases." (1982). LSU Historical Dissertations and Theses. 3730.