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 C-H center dot center dot center dot 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 I-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 C-H... 0, C-H center dot center dot center dot pi and C-H center dot center dot center dot F have been analyzed. (C) 2008 Elsevier B.V. All rights reserved.