Hydrogen-bonding motifs in 3-carboxyanilinium bromide and iodide

In the title compounds, C(7)H(8)NO(2)(+).Br(-), (I), and C(7)H(8)NO(2)(+).I(-), (II), the asymmetric unit contains a discrete 3-carboxyanilinium cation, with a protonated amine group, and a halide anion. The compounds are not isostructural, and the crystal structures of (I) and (II) are characterized by different two-dimensional hydrogen-bonded networks. The ions in (I) are connected into ladder-like ribbons via N-H...Br hydrogen bonds, while classic cyclic O-H...O hydrogen bonds between adjacent carboxylic acid functions link adjacent ribbons to give three characteristic graph-set motifs, viz. C(2)(1)(4), R(4)(2)(8) and R(2)(2)(8). The ions in (II) are connected via N-H...I, N-H...O and O-H...I hydrogen bonds, also with three characteristic graph-set motifs, viz. C(7), C(2)(1)(4) and R(4)(2)(18), but an O-H...O interaction is not present.