ACTA CRYSTALLOGRAPHICA SECTION E-CRYSTALLOGRAPHIC COMMUNICATIONS, cilt.74, ss.1669-1682, 2018 (ESCI)
The asymmetric unit of the title compound, C16H20N2O2, consists of two independent molecules differing slightly in the conformations of the seven-membered rings and the butyl substituents, where the benzene rings are oriented at a dihedral angle of 34.56 (3)degrees. In the crystal, pairwise intermolecular C-H center dot center dot center dot O and complementary intramolecular C-H center dot center dot center dot O hydrogen bonds form twisted strips extending parallel to (012). These strips are connected into layers parallel to (111) by additional intermolecular C-H center dot center dot center dot O hydrogen bonds. The layers are further joined by C-H center dot center dot center dot pi interactions. The Hirshfeld surface analysis of the crystal structure indicates that the most important contributions for the crystal packing are from H center dot center dot center dot H (65.5%), H center dot center dot center dot C/C center dot center dot center dot H (16.0%) and H center dot center dot center dot O/O center dot center dot center dot H (15.8%) interactions.