presence of a strong intermolecular N-H•••O interaction. In case of 7, the possibility of such an interaction is obviated by the formation of an intramolecular N-H•••O hydrogen bond. An additional feature of the crystal packing for 1—6 is the significant roles that C—H•••π contacts play in generating three dimensional networks. In contrast for 7, the intramolecularN—H•••O hydrogen bond precludes the formation