Lewis acid interhalogen compounds

C21-0093. Some pure liquid interhalogen compounds are good electrical conductors, indicating that they contain cations and anions. Show a Lewis acid-base reaction between two bromine trifluoride molecules that would generate ionic species. 

The interhalogen compounds obey the expectations based on the VSEPR theory, and typical structures are giver in Chapter 6. Ore compound not included there is the dimeric iodine trichloride, in which the iodine atom of the monomeric species appears to act as a Lewis acid and accept an additional pair of electrons from a chlorine atom (Fig. 17.5). 

On the basis of self-ionic dissociation, these compounds can be prepared by acid-base reactions. Heteropolyhalogen cations are usually prepared by reacting the parent compound with a Lewis acid (equation 51) in which XY = interhalogen and MYm = Lewis acid, for example, hahdes of B, Al, P, As, and Sb, and so on (equations 52 and 53). Such reactions can be performed by direct interaction of the reactants with an excess of the more volatile reactant, which can then be pumped off, after completion of the reaction, leaving behind the pure product. Sometimes it is preferable to perform such reactions in solution, such as in anhydrous hydrogen fluoride (AHF), and pump off the solvent at the end of the reaction. 

El 7.10 SbFs is a strong Lewis acid and extracts a fluoride ion from the interhalogen compound CIF5, leading to the... 

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