Four bromine-substituted 2,5-di(1,3-dithiol-2-ylidene)-1,3-dithiolane-4-thione derivatives, 1a, 1b, 1c, and 1d, were synthesized, and their physical properties were investigated. These compounds were obtained from the reaction of a corresponding zinc complex of 2-(1,3-dithiol-2-ylidene)-1,3-dithiole-4,5-bis(thiolate) derivatives and corresponding tetrafluoroborate salts of 1,3-dithiol-2-ylium derivatives. Recrystallization of 1a from carbon disulfide and n-hexane gave single crystals suitable for X-ray structure analysis. In the crystal, 1a molecules are one-dimensionally stacked and one molecule is rotated relative to the neighboring molecules by an angle of 92° about its longer molecular axis. On the (010) plane, the molecules were arranged in a zigzag manner along the a axis. This interesting feature is accomplished by intermolecular S···Br halogen bonds.

The asymmetric unit of the title compound, C9H4S7, contains two independent mol­ecules, in one of which the central five-membered ring is disordered over two orientations in a 0.924 (3):0.076 (3) ratio. The mol­ecular skeleton is almost planar: the average distance of the atoms from their mean plane is 0.128 (7) Å in the ordered mol­ecule, and 0.088 (5) and 0.123 (2) Å in the major and minor disorder components, respectively. The ordered and disordered mol­ecules form separate columns by stacking along the b axis. Adjacent columns inter­act via short S⋯S [3.33 (2), 3.434 (3), 3.444 (2), 3.503 (2), 3.519 (3) and 3.53 (4) Å] and S⋯H [2.814 (2), 2.87 (7), 2.92 (2), 2.9269 (18), 2.93 (2), 2.94 (2), 2.939 (2), 2.967 (2) and 2.974 (1) Å] contacts.