Analysis of weak interactions involving organic fluorine: Insights from packing features in substituted 4-keto-tetrahydroindoles

The role of “organic fluorine” in controlling the packing motifs in crystal structures which possess both strong and weak intra- and intermolecular interactions reveal that CH…F hydrogen bonded networks provide additional stability. In this context, the crystal structures of seven new compounds have been investigated based on the molecular motif 1,5,6,7-tetrahydro-4H-indol-4-one with 4-fluorophenyl substitutions at the “para” position on the 1-phenyl ring in four compounds and different substituents on the five-membered ring in the remaining three compounds. The features of conformational changes and the flexibility in packing based on CH…O, CH…π and CH…F have been analyzed.