Recent Discoveries of Polyhalogen Anions - from Bromine to Fluorine

In this review we discuss the recent discoveries in polyhalide anion chemistry with the main focus on polybromide, -chloride, and -fluoride anions. Based on novel synthetic strategies either in ionic liquids or in neat halogens several new polyhalides of bromine and chlorine were synthesized. Beyond these discoveries the chemistry of polyfluoride monoanions is reviewed. Such species were investigated under cryogenic conditions at 4 K in conjunction with quantum-chemical calculations. In addition to these bonding and structural discussions, an overview of possible applications of such polyhalide anions is provided.