Does the Naked Fluoride Ion Exist?

Of course in a chemical environment the F − ion cannot exist —this is the answer to the question in the title of this highlight. But in 1991 two reagents were described that make an almost naked fluoride ion available. K. O. Christl et al. synthesized for the first time pure Me 4 N + F − , from which complex fluoro anions with high coordination numbers can be prepared (for example, [XeF 5 ] − and [IF 8 ] − ). R. Schwesinger et al. succeeded in preparing anhydrous [(Me 2 N) 3 PNP (NMe 2 ) 3 ] + F − , which has an extremely large cation–anion distance and promises to be a useful reagent in organic synthesis.