Packing effects in 4,4'-bis(4-hydroxybutyl)-2,2'-bipyridine and 4,4'-bis(4-bromobutyl)-2,2'-bipyridine.

Structure analyses of 4,4'-bis(4-hydroxybutyl)-2,2'-bipyridine, C18H24N2O2, (I), and 4,4'-bis(4-bromobutyl)-2,2'-bipyridine, C18H22Br2N2, (II), reveal intermolecular hydrogen bonding in both compounds. For (I), O-H...N intermolecular hydrogen bonding leads to the formation of an infinite two-dimensional polymer, and pi stacking interactions are also observed. For (II), C-H...N intermolecular hydrogen bonding leads to the formation of a zigzag polymer. The two compounds crystallize in different crystal systems, but both molecules possess Ci symmetry, with one half molecule in the asymmetric unit.