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
| Identifer | oai:union.ndltd.org:ORGSU/oai:ir.library.oregonstate.edu:1957/33996 |
| Date | 30 May 1996 |
| Creators | Truska, Scott |
| Contributors | Gleicher, Gerald Jay |
| Source Sets | Oregon State University |
| Language | en_US |
| Detected Language | English |
| Type | Thesis/Dissertation |
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