Analysis of intermolecular interactions involving halogens in substituted benzanilides

Crystal structures of halogen-substituted benzanilides have been analyzed in terms of weak interactions involving halogens. The four compounds namely 3-fluoro-N-(3-hydroxyphenyl)benzamide, 3-chloro-N-(3-hydroxyphenyl)benzamide, 3-fluoro-N-(4-methylphenyl)benzamide and 3-chloro-N-(4-methylphenyl)benzamide crystallize in monoclinic symmetry. The packing modes in the crystalline lattice generate motifs via N–H· · ·O and O–H· · ·O hydrogen bonds in structures 1 and 2 and via N–H· · ·O hydrogen bond, weak C–H· · ·F and Cl· · ·Cl interactions in structures 3 and 4. These structures when compared with the polymorphs of benzanilide show no orientational disorder and depict subtle conformational changes, which are directed by both strong hydrogen bonds and weak interactions involving halogens. q 2004 Elsevier B.V. All rights reserved.