A three part study involving aspects of radical properties of various aromatic species was accomplished. Experiments to ascertain the importance of geometric and electronic effects on the intramolecular transfer of a pi-complexed radical to a terminal double bond was performed. Several 4-aryl-1-butenes were reacted in competition with 1-undecene with a variety of radical precursors at 70��C. The reactions were studied in both complexing and noncomplexing solvents. Most of the relative rates varied little from unity and no dependence on solvent was observed. A series of 21 phenacylarenes was subjected to mass spectrometry. The fragmentation process leading to arylmethyl radicals and benzoyl cations was measured by calculating the ratios of parent ion to benzoyl cation signal strength. In the case of the eleven homoaromatic compounds little overall correlation of these values to traditionally accepted arylmethyl radical stabilities was found. The degree of fragmentation for isomers of the same compound were found to be explicable in term of arylmethyl radical stabilities. Degrees of fragmentation of some compounds could be rationalized in terms of the bond order of the bond being broken, as calculated by AM1 methods. The ten heteroaromatic compounds showed little correlation of fragmentation with bond order. The degree of fragmentation was found to be dependent on many different variables of the individual molecules. No correlation with any one factor could be found. The relative rates of benzylic hydrogen atom abstraction from a series of substituted toluenes and cumenes under conditions of bromination by diethyl bromomalonate were determined at 70��C. A range of reactivity of 21.7 and 10.5 was found for the toluenes and cumenes respectively. The relative rates were found to correlate best with Hammett sigma plus constants. Hammett values of -0.89 and -0.73 were calculated for the substituted toluenes and cumenes. Reactivities for several alkyl benzenes having different steric requirements at the reaction site were also studied. The relative rates for these compounds indicate a relatively large radical to be the atom abstracting agent. The results of the Hammett correlations combined with the studies involving the steric properties of the abstracting radical suggest that diethyl malonyl radical is the hydrogen atom abstracting species. / Graduation date: 1997

The fluorescence spectrum of many polycyclic aromatic compounds (PACs) depends upon solvent polarity. The emission spectrum of PAC monomers consists of several major vibronic bands labeled I, II, etc., in progressive order. Emission intensity enhancement of select bands is observed in polar solvents.