Thione vs. ketone: The influence of the chalcogenide on weak intermolecular interactions in crystal packing of 4,5-bis(bromomethyl)-1,3-dithiole-2-thione and 4,5-bis(bromomethyl)-1,3-dithiol-2-one

Crystal structures of 4,5-bis(bromomethyl)-1,3-dithiole-2-thione (1) and 4,5-bis(bromomethyl)-1,3-dithiol-2-one (2) were determined and analyzed. Both compounds pack in the same C2/c space group and adopt very similar molecular geometries. Patterns of intermolecular contacts, analyzed with the help of Hirshfeld surfaces and fingerprint plots, on the other hand, are remarkably different. The dominant interactions in the packing of 1 are short Br⋯Br contacts and non-classical CH⋯Br hydrogen bonds. For 2, the packing is governed by short CH⋯OC hydrogen bonds, and longer CH⋯Br and S⋯Br contacts play only a secondary role.

► X-ray structures of two heterocyclic compounds were determined and analyzed.
► Hirshfeld surfaces were used for efficient analysis of intermolecular contacts.
► Molecular backbones of both compounds form stacks in the crystal phase.
► Packing of thione is determined by short Br⋯Br and CH⋯Br interactions.
► Packing of ketone is dominated by notably short CH⋯OC hydrogen bonds.