Lewis Acid Induced Intramolecular Redox Reactions of Difluoramino Compounds

摘要

It is shown that strong Lewis acids, such as AsF5 or SbF5, which are good fluoride ion acceptors, strongly catalyze an intramolecular redox reaction of difluroramino compounds, such as CF3NF2, SF5NF2, ClNF2, CF3ONF2, and SF5ONF2. In the ClNF2-AsF5 system a termally unstable intermediate is formed at -78 C, which on the basis of its Raman spectra is the fluorine-bridge donor-acceptor adduct ClNF2.AsF5. The nature of the final decomposition products can be rationalized in terms of their stability. In connection with the low-temperature Raman studies, an unidentified, unstable, blue-green species was observed that gives rise to a resonance Raman spectrum with v = 177/cm and that is formed from Cl3(+)AsF6(-) and excess Cl2. For NF2Cl,14N-19F spin-spin coupling was observed in its 19F NMR spectrum.