“A halogen bond occurs when there is evidence of a net attractive interaction between an electrophilic region associated with a halogen atom in a molecular entity and a nucleophilic region in another, or the same, molecular entity.”
“Definition of the halogen bond (IUPAC Recommendations 2013)” – Gautam R. Desiraju, P. Shing Ho, Lars Kloo, Anthony C. Legon, Roberto Marquardt, Pierangelo Metrangolo, Peter Politzer, Giuseppe Resnati and Kari Rissanen – Pure Appl. Chem., Vol. 85, No. 8, pp. 1711–1713, 2013.