Halogen Bonding: a Lump-Hole Interaction

It is well known that halogen atoms can act as electron acceptors and interact with electron donor species. This type of noncovalent interaction usually called halogen bonding , in order to emphasize the similarity with hydrogen bonding. A halogen bond, XB, is indicated by A − X LB in which the halogen bond acceptor, B, should be an electron donor such as oxygen, nitrogen or sulfur. X is typically iodine, bromine, chlorine and rarely fluorine, which strength of the interaction increases in order (F <)