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Calichman, Michael F.

Chemistry

2006

PhD

A series of homogeneously substituted cyclotriphosphazenes are modeled and their bonding and reactivity properties investigated utilizing ab initio and densityfunctional calculations at a high level of theory. Substituents range from the halogens, chalcogens, nitrogen group, and carbon group elements, to the boranes and alkali group metals. Results and conclusions drawn from these investigations are applied to explain geometrical and other properties observed in varying phosphazene systems; including intraannular bond lengths in heterogeneously substituted cyclotriphosphazenes, the effect of the phosphazene group on a bonded olefin group, and the basicity observed in substituted cyclophosphazenes. The kinetics of phenolate substitution of hexafluorocyclotriphosphazene and hexachlorocyclotriphosphazene are investigated including study of the effects of varying solvents, alkali counterions, and temperature.
The activation parameters [delta]G[standard Gibbs energy of activation symbol], [delta]H[standard enthalpy of activation symbol], [delta]S[standard of entropy of activation symbol] are determined, and the results compared to those found in amino addition. The monomers (4- methacylbutoxy)cyclohalotriphosphazene (halo = chloro, fluoro) have been synthesized, copolymerized with methyl methacrylate, and the resulting copolymers evaluated for polydispersity, reactivity ratios of the monomers, and thermal stability. Using transitionmetal catalysts to polymerize (allylalkoxy)pentachlorocyclotriphosphazene was attempted, as was synthesis of styrenyl-pentafluorocyclotriphosphazene by several parallel routes.