1,4-Dibromo-2,5-bis(phenylalkoxy)benzene Derivatives: C-Br...π(arene) Versus C-H...Br and Br...Br Interactions in the Solid State

We have prepared and characterized 1,4-dibromo-2,5-bis(2-phenylethoxy)benzene ( 1 ) and 1,4-dibromo-2,5-bis(3-phenylpropoxy)benzene ( 2 ). Their single-crystal structures confirm that, at the molecular level, they are similar with the phenylalkoxy chains in extended conformations. However, there are significant differences in packing interactions. The packing in 1 is dominated by C-Br...π(arene) interactions, with each Br located over one C-C bond of the central arene ring of an adjacent molecule. In contrast, the packing of molecules of 2 involves a combination of C-H...Br hydrogen bonds, Br...Br interactions, and arene-arene π-stacking. The single-crystal structures of both orthorhombic and triclinic polymorphs of 1 have been determined and the packing interactions are shown to be essentially identical.