Abstract：This paper reviewed recent theoretical research progress of halogen bonding interactions in ionic liquids and raised the potential application of halogenated ionic liquids in acid gas absorption. Relative to hydrogen bonds in ionic liquids, halogen bonds between the cations and anions showed a strong directionality. There exsited halogen-bonded ring structures in halogenated ionic liquids, and moreover halogen atoms in the cations could interact with CO2 molecule through X???O weak interactions. Therefore, the solubility of CO2 in halogenated ionic liquids might increase. In view of the unique structures and properties of halogenated ionic liquids, much forthcoming attention should be focus on the investigation of the relationship between the structure and functionality of halogenated ionic liquids, the dynamic features of these ionic lqiuids, and the solubility mechnism of acid gas in these ionic liquids.
