Supramolecular polymers of 4,5-bis(bromomethyl)-1,3-dithiole-2-thione-dihalogen adducts

The title compound has been reacted with I2, IBr and ICl to afford the charge-transfer adducts 4.2I2, 4.IBr and 4.ICl.½I2, respectively. The products have been characterised by Raman and IR spectroscopy and X-ray crystallography. The adducts contain linear S…I-X (X=I, Br or Cl) units (174-178degrees) in which the S…I contacts range from 2.534–2.597 AAngstrom. In 4.2I2 and 4.ICl.½I2, the materials contain additional ‘free’ diiodine units which are held within a matrix of intermolecular contacts, predominantly through non-covalent halogen–halogen and sulfur–halogen interactions. Although the functional groups in the parent molecule (4) are inert at the supramolecular level, the bromomethyl groups in the adducts contribute strong interactions through Br…Br, Br…I, Br…S and Br…H close contacts. The structures of the complexes are polymeric in nature,providing interactions in two and three dimensions.