Carbocations and Onium ions
In studying hydrocarbons and their conversions a wide variety of highly acidic systems called superacids have been developed. When higher valent Lewis acid fl uorides such as SbF5 and TaF5 are combined with Brönsted acids such as HF or FSO3H, acids many billions of times stronger than sulfuric acid are obtained. In such superacidic media the lifetime of carbocations are suffi ciently long to be examined by a variety of chemical and physical methods including nuclear magnetic resonance and photoelectron spectroscopy.
These intermediates are fundamental to the understanding of acid catalyzed processes. Related to work on carbocations and their reactions, investigation of onium ions and ylides have been undertaken. New types of oxonium, halonium and other onium ions were also prepared and studied at the Institute.
The role of electrophilic (protolytic) solvation of onium ions is explored, allowing broad new applications in alkylation, acylation, and nitration reactions involving highly reactive superelectrophiles.