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

Abstract

The structure of the title compounds 3-bromo-2-(phenyl-sulfan-yl)benzo[b]thiophene (C₁₄H₉BrS₂; 1), 3-iodo-2-(phenyl-sulfan-yl)benzo[b]thio-phene (C₁₄H₉IS₂; 2), 3-bromo-2-(phenyl-selan-yl)benzo[b]seleno-phene (C₁₄H₉BrSe₂; 3), and 3-iodo-2-(phenyl-selan-yl)benzo[b]seleno-phene (C₁₄H₉ISe₂; 4) were determined by single-crystal X-ray diffraction; all structures presented monoclinic (P2₁/c) symmetry. The phenyl group is distant from the halogen atom to minimize the steric hindrance repulsion for all structures. Moreover, the structures of 3 and 4 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*_Se-C orbital (n _halogen→σ*_Se-C). 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[b]chalcogenophenes, which is relevant for optoelectronic applications.

Keywords: benzo[b]chalcogenophenes; crystal structure; intra­molecular orbital inter­action.

Figure 1

The mol­ecular structure of 3-bromo-2-(phenyl­sulfan­yl)benzo[b]thio­phene (1), with displacement ellipsoids drawn at the 50% probability level.

Figure 2

The mol­ecular structure of 3-iodo-2-(phenyl­sulfan­yl)benzo[b]thio­phene (2), with displacement ellipsoids drawn at the 50% probability level.

Figure 3

The mol­ecular structure of 3-bromo-2-(phenyl­selan­yl)benzo[b]seleno­phene (3), with displacement ellipsoids drawn at the 50% probability level.

Figure 4

The mol­ecular structure of 3-iodo-2-(phenyl­selan­yl)benzo[b]seleno­phene (4), with displacement ellipsoids drawn at the 50% probability level.

Figure 5

Representation of the inter­planar angle (α) between the planes containing the phenyl­sulfanyl, blue plane, and the benzo[b]thio­phene, purple plane, groups for 3-bromo-2-(phenyl­sulfan­yl)benzo[b]thio­phene (1). Displacement ellipsoids are drawn at the 50% probability level. Gray: carbon; yellow: sulfur; light green: bromine; white: hydrogen.

Figure 6

Representation of the inter­planar angle (α) between the planes containing the phenyl­sulfanyl, blue plane, and the benzo[b]thio­phene, purple plane, groups for 3-iodo-2-(phenyl­sulfan­yl)benzo[b]thio­phene (2). Displacement ellipsoids are drawn at the 50% probability level. Gray: carbon; yellow: sulfur; bluish green: iodine; white: hydrogen.

Figure 7

Representation of the inter­planar angle (α) between the planes containing the phenyl­selanyl, blue plane, and the benzo[b]seleno­phene, purple plane, groups for 3-bromo-2-(phenyl­selan­yl)benzo[b]seleno­phene (3). Displacement ellipsoids are drawn at the 50% probability level. Gray: carbon; orange: selenium; light green: bromine; white: hydrogen.

Figure 8

Representation of the inter­planar angle (α) between the planes containing the phenyl­selanyl, blue plane, and the benzo[b]seleno­phene, purple plane, groups for 3-iodo-2-(phenyl­selan­yl)benzo[b]seleno­phene (4). Displacement ellipsoids are drawn at the 50% probability level. Gray: carbon; orange: selenium; bluish green: iodine; white: hydrogen.

Figure 9

Representation of some mol­ecules of 3-bromo-2-(phenyl­sulfan­yl)benzo[b]seleno­phene (1) viewed approximately down the c axis of the unit cell. The red dashed lines represent C—H⋯π inter­actions involving the H5 atom of the benzo[b]thio­pehene ring with an adjacent phenyl­sulfanyl group; the purple dashed lines represent π–π stacking inter­actions between adjacent benzo[b]thio­pehene rings. Displacement ellipsoids are drawn at the 50% probability level. The hydrogen atoms, except for H4, are omitted for clarity. Red and purple spheres represent the centroids of the respective organic groups.

Figure 10

Representation of the mol­ecules of 3-bromo-2-(phenyl­selan­yl)benzo[b]seleno­phene (3) viewed down the c axis of the unit cell. The purple and yellow dashed lines represent π–π stacking inter­actions between adjacent benzo[b]thio­pehene rings and between adjacent phenyl­sulfanyl groups, respectively. Displacement ellipsoids are drawn at the 50% probability level. The hydrogen atoms were omitted to clarity. Purple and yellow spheres represent the centroids of the respective organic groups.