Crystal structures of p-substituted derivatives of 2,6-di­methyl­bromo­benzene with ½ ≤ Z′ ≤ 4

The crystal structures of four bromo-arenes based on 2,6-di-methyl-bromo-benzene are reported, which are differentiated according the functional group X placed para to the Br atom: X = CN (4-bromo-3,5-di-methyl-benzo-nitrile, C9H8BrN), (1), X = NO2 (2-bromo-1,3-dimethyl-5-nitro-benzene, C8H8BrNO2), (2), X = NH2 (4-bromo-3,5-di-methyl-aniline, C8H10BrN), (3) and X = OH (4-bromo-3,5-di-methyl-phenol, C8H9BrO), (4). The content of the asymmetric unit is different in each crystal, Z' = ½ (X = CN), Z' = 1 (X = NO2), Z' = 2 (X = NH2), and Z' = 4 (X = OH), and is related to the mol-ecular symmetry and the propensity of X to be involved in hydrogen bonding. In none of the studied compounds does the crystal structure feature other non-covalent inter-actions, such as π-π, C-H⋯π or C-Br⋯Br contacts.