Crystal structure and Hirshfeld surface analysis of supramolecular aggregate of 2,2,6,6-tetramethylpiperidin- 1-ium bromide with 1,2,3,4-tetrafluoro- 5,6-diiodobenzene

Summary: The asymmetric unit of the title compound, C9H20N+Br^- * C6F4I2, contains one 2,2,6,6-tetramethylpiperidine-1-ium cation, one 1,2,3,4-tetrafluoro-5,6-diiodobenzene molecule, and one uncoordinated bromide anion. In the crystal, the bromide anions link the 2,2,6,6-tetramethylpiperidine molecules by intermolecular C-H...Br and N-H...Br hydrogen bonds, leading to dimers, with the coplanar 1,2,3,4-tetrafluoro-5,6-diiodobenzene molecules filling the space between them. There is a pi-pi interaction between the almost parallel benzene rings [dihedral angle = 10.5 (2) deg] with a centroid-to-centroid distance of 3.838 (3) A and a slippage of 1.468 A. No C-H...pi(ring) interactions are observed. A Hirshfeld surface analysis indicates that the most important contributions for the crystal packing are from H...F/F...H (23.8%), H...H (22.6%), H...Br/Br...H (17.3%), and H...I/I...H (13.8%) interactions. Hydrogen bonding and van der Waals interactions are the dominant interactions in the crystal packing.