Crystal structures of 3-halo-2-organochalcogenylbenzo[]chalcogenophenes.

The structure of the title compounds 3-bromo-2-(phenyl-sulfan-yl)benzo[]thiophene (CHBrS; ), 3-iodo-2-(phenyl-sulfan-yl)benzo[]thio-phene (CHIS; ), 3-bromo-2-(phenyl-selan-yl)benzo[]seleno-phene (CHBrSe; ), and 3-iodo-2-(phenyl-selan-yl)benzo[]seleno-phene (CHISe; ) were determined by single-crystal X-ray diffraction; all structures presented monoclinic (2/) symmetry. The phenyl group is distant from the halogen atom to minimize the steric hindrance repulsion for all structures. Moreover, the structures of and show an almost linear alignment of halogen-selenium-carbon atoms arising from the intra-molecular orbital inter-action between a lone pair of electrons on the halogen atom and the anti-bonding σ* orbital ( →σ*). This inter-action leads to significant differences in the three-dimensional packing of the mol-ecules, which are assembled through π-π and C-H⋯π inter-actions. These data provide a better comprehension of the inter-molecular packing in benzo[]chalcogenophenes, which is relevant for optoelectronic applications.