Diarylhalonium ions

Diarylhalonium Ions. In contrast to dialkylhalonium ions and alkylarylhalonium ions, diarylhalonium ions are considerably more stable. This is particularly the case for diaryliodonium ions, which have been known for 110 years.328a It is interesting,... 

Olah et al.381,382 have studied the 13C NMR spectra of a series of diarylhalonium ions. Some of the representative diarylhalonium ions are ions 154-157." The synthesis of these diarylhalonium ions does not require strongly acidic conditions and thus will not be discussed here. The use of arylstannane and arylsilane precursors in the synthesis of diarylhalonium ions has been reviewed332 and the X-ray structure analysis of a number of these ions has also been reported. Frohn and co-workers... 

Dialkylhalonium ions are highly reactive spedes and have been detected only as reactive intermediates in organic reactions. In contrast, diarylhalonium salts are colorless, crystalline compounds that are quite stable at room temperature and above. These compounds can be prepared by straightforward electrophilic aromatic substitution chemistry. They are generally insoluble in water but freely soluble in common organic solvents from which they can be purified by the usual chromatographic and crystallization techniques. 

---