Halogen-bonded adduct of 1,2-dibromo-1,1,2,2-tetrafluoroethane and 1,4-diazabicyclo[2.2.2]octane.

Halogen bonding is an inter�molecular inter�action capable of being used to direct extended structures. Typical halogen-bonding systems involve a noncovalent inter�action between a Lewis base, such as an amine, as an acceptor and a halogen atom of a halo�fluoro�carbon as a donor. Vapour-phase diffusion of 1,4-di�aza�bicyclo�[2.2.2]octane (DABCO) with 1,2-di�bromo�tetra�fluoro�ethane results in crystals of the 1:1 adduct, C2Br2F4�C6H12N2, which crystallizes as an infinite one-dimensional polymeric structure linked by inter�molecular N...Br halogen bonds [2.829 (3) �], which are 0.57 � shorter than the sum of the van der Waals radii.