2,5-Dichloro-1,4-benzoquinone (DCBQ) is a halogenated quinone. DCBQs are carcinogenic intermediates. They have benn identified as chlorination disinfection byproducts in drinking water. DCBQ has been reported to increse the decomposition of a model ROOH tert-butylhydroperoxide, via formation of t-butoxyl radicals. The isomers of the DCBQ dimer have been investigated for the non-covalent interactions (NCIs) by quantum chemical calculations. Halogen bond present in 2,5-dichloro-1,4-benzoquinone have been investigated by experimental as well as theoretical charge density analysis. Its reaction with pyrrolidine has been investigated.