Aspects of radical cation chemistry and possible applications to coal model compound reactions.

摘要

The following manuscript is a description of our efforts over the last five years to investigate and elucidate the chemical parameters and mechanisms that lead to the C-C bond cleavage reactions in organic compounds.; Motivation to perform this work was provided by the reactions of certain coal model compounds under coal liquefaction conditions. These coal model compounds were found to cleave the bond connecting the naphthalene ring to the remainder of the molecule and the reactivity was attributed to be due to radical cation behavior. This behavior was different than the reactivity of radical cations of similar phenyl-containing compounds. Our contribution to this field involves the investigation of the C-C bond cleavage reactions of the radical cations of naphthyl-containing compounds.; Chapter I illustrates the generation of the radical cations of naphthyl-containing compounds in solution and gas phase and their bond cleavage reactions. Their reactivity was compared to the corresponding reactivity under catalytic conditions.; Chapter II examines the general oxidation reactions of the above-mentioned compounds. The purpose was to investigate the effects of counterion on the reactions. The remainder of this chapter is devoted to the investigations of the dehydrogenation reactions of related compounds. There has been interest recently in the development of new and milder dehydrogenating reagents. Three Fe compounds were found to produce the desired dehydrogenation reactivity at relatively low temperatures (130{dollar}spcirc{lcub}rm C{rcub}).{dollar}; The final chapter of this manuscript discusses the results and conclusions derived from the sensitized irradiation of a series of esters by a triphenylpyrylium salt and oxygen. These esters were found to undergo C-C bond cleavage reactions and these reactions were found to arise by a oxygen-induced radical chain autoxidation reaction and not by radical cationic behavior as has been proposed in the literature.; It is my hope that future work will be devoted to further our understanding of the general oxidations and dehydrogenations of some substrates by Fe compounds. What role does the C10{dollar}sb4sp{lcub}-{rcub}{dollar} play in these reactions? Is a radical cation intermediate involved here? These are only a few of the potential avenues that can be examined by using this manuscript as a guide. I am sure that there are more unexpected and exciting reactions waiting to be observed in the systems such as those described in this text.