Dimorphic Forms in a Non-Centrosymmetric Environment from a Prochiral Molecule: Cooperative Interplay of Strong Hydrogen Bonds and Weak Intermolecular Interactions

4-Fluoro-N-(2-fluorophenyl) benzamide, a prochiral molecule, exhibits dimorphic behavior. This feature has
been analyzed in terms of morphology, X-ray single-crystal structure analysis, differential thermal analysis, and
measurement of second harmonic generation (SHG) in both forms, which crystallize in noncentric space groups. The
dimorphs have different morphologies, a major form as needles and a minor form as thin plates, occurring concomitantly
in the same crystallization setup. The plates crystallize in the monoclinic space group P21, while the needles are in the
orthorhombic space group Pca21. Strong N−H···O hydrogen bonds and weak but highly directional C−H···F interactions
acting cooperatively are responsible for the observed symmetry steering the molecules to pack in noncentric environments.