C–H⋯X hydrogen-bond-mediated supramolecular frameworks: Syntheses and crystal structures of hydrochlorate hexafluorophosphorate and hydrochlorate tetrafluoroborate of 4′-chloro-2,2′:6′,2″-terpyridine

C–H⋯F and C–H⋯Cl hydrogen bonding interactions play essential roles in forming different supramolecular networks of 4′-chloro-2,2′:6′,2″-terpyridine hydrochlorate hexafluorophosphorate (1) and 4′-chloro-2,2′:6′,2″-terpyridine hydrochlorate tetrafluoroborate (2) in the solid state, where different crystallographic symmetry, molecular structures and packing patterns have been achieved. The former crystallizes in the triclinic P − 1 space group and the terpyridine system is staggered with the dihedral angles of 11.8°, 4.1° and 22.5°, 3.3° between the central ring and the other ones (two sets of molecules in the asymmetric unit). In contrast, the latter packs into the orthorhombic Pnma space group in which only planar molecules and layer stacking are present. This is a remarkable example on how subtle differences in the molecular formulae give a large difference in supramolecular packing.