Crystal structure and Hirshfeld surface of 5-bromosalicylic acid dimethylformamide monosolvate

Abstract

The structure of the title compound, C 7 H 5 BrO 3 ·C 3 H 7 NO, at 173 K has triclinic ( P 1 ) symmetry with Z = 4. The asymmetric unit comprises two molecules of 5-bromosalicylic acid and two molecules of N , N -dimethylformamide (DMF). The crystal structure is dominated by strong O—H...O hydrogen bonds between the carboxylic acid group of the 5-bromosalicylic acid molecules and the carbonyl oxygen atom of the DMF molecules, with the solvent acting as a hydrogen-bond acceptor. This interaction prevents the formation of the common carboxylic acid dimer observed in many benzoic acid derivatives. Additional C—H...O hydrogen bonds and Br...O non-covalent interactions between neighbouring molecules contribute to the cohesion of the structure. Aromatic π–π stacking interactions between adjacent benzene rings further consolidate the crystal structure and generate a three-dimensional supramolecular assembly. Hirshfeld surface analysis confirms that H...H, H...O/O...H and Br...H/H...Br contacts make the largest contributions to the crystal packing. The inclusion of DMF therefore plays a significant role in directing the intermolecular interactions and overall supramolecular packing of the crystal structure.