4′-substituted 2,2′:6′,2′′-terpyridine AIM Atoms Atoms in Molecules Bader's theory Bonding character Columnar arrays Crystal atomic structure Crystal structure Hydrogen bonds Ions Molecules Non-covalent interaction Supramolecular structure Terpyridines Title compounds atoms-in-molecules attractive H..H interaction attractive H⋯H interaction crystal structure theoretical characterization