2,5-Dibromopyridine

In the title compound, C5H3Br2N, C—H⋯N hydrogen-bonding interactions and Br⋯Br interactions [3.9418 (3) and 3.8986 (3) Å] connect the molecules into planar sheets stacked perpendicular to the b axis. In addition, pyridyl–pyridyl intersheet π–π stacking interactions [centroid–centroid distance = 4.12 (1) Å] result in a three-dimensional network.

Al-Balqa'a Applied University and Al al-Bayt University are thanked for financial support.
Supplementary data and figures for this paper are available from the IUCr electronic archives (Reference: PV2146). 2,5-bibromopyridinium cation. The compound had not been reported previously, thus, the structure of (I) has been characterized crystallographically and is presented here.

Structure Reports Online
The bond distances and angles within the molecule of (I) (Fig. 1) are normal (Allen et al., 1987). There is a non-classical hydrogen bonding interaction of the type C-H···N in the crystal structure which links molecules into one-dimensional chains ( Fig. 2) parallel to the a-axis. The strength of the hydrogen bonds is represented by relatively short D···A distance and D-H···A angle (H···A = 2.38 Å, D-H···A 175°, Table 1). The resulting chains are further connected through Br···Br interactions in a zig zag arrangement to form sheets in the ac plane (Fig. 2); the Br···Br separation being 3.9418 (3) and 3.8986 (3) Å. The sheets are stacked along the b-axis with pyridyl···pyridyl π···π stacking intermolecular inreactions with distance between the centroids of the rings being 4.12 (1) Å. It is noteworthy that structural and theoritical results (Awwadi et al., 2006;Awwadi et al., 2007), show the significance of Br···Br bonding synthons in influencing structures of crystalline materials and in use as potential building blocks in crystal engineering via supramolecular synthesis.

Experimental
The title compound crystallized during a reaction aiming to crystallize the anion [CuBr 4 ] 2with 2,5-dibromopyridinium cation. Colorless diamond like crystals of the title compound were obtained from an ethanolic solution of the reaction which involved a sequential addition to excess 2,5-dibrormopyridine (2.25 mmole) in ethanol of CdCl 2 (1 mmole) and 60% HBr (1 ml) in ethanol.

Refinement
Hydrogen atoms were positioned geometrically, with C-H = 0.95 Å, and constrained to ride on their parent atoms with U iso (H) = 1.2U eq (C).