Crystal structures of 3-fluoro-N-[2-(trifluoromethyl)phenyl]benzamide, 3-bromo-N-[2-(trifluoromethyl)phenyl]benzamide and 3-iodo-N-[2-(trifluoromethyl)phenyl]benzamide

Abstract

In the title compounds, C14H9F4NO, (I), C14H9BrF3NO, (II), and C14H9F3INO, (III), the two benzene rings are inclined to one another by 43.94 (8)° in molecule A and 55.66 (7)° in molecule B of compound (I), which crystallizes with two independent molecules in the asymmetric unit, but by only 10.40 (12)° in compound (II) and 12.5 (2)° in compound (III). In the crystals of all three compounds, N—H...O hydrogen bonds link the molecules to form chains propagating along the a-axis direction for (I), and along the b-axis direction for (II) and (III). In the crystal of (I), –A–B–A–B– chains are linked by C—H...O hydrogen bonds, forming layers parallel to (010). Within the layers there are weak offset π–π interactions present [intercentroid distances = 3.868 (1) and 3.855 (1) Å]. In the crystals of (II) and (III), the chains are linked via short halogen–halogen contacts [Br...Br = 3.6141 (4) Å in (II) and I...I = 3.7797 (5) Å in (III)], resulting in the formation of ribbons propagating along the b-axis direction.

Keywords

• crystal structure
• amide
• benzamide
• 2-(trifluoromethyl)phenyl
• N—H...O hydrogen bonding
• halogen–halogen contacts