2,2':4,4'':4',4'''-Quaterpyridine: synthesis, crystal-structure description, and Hirshfeld surface analysis.

The title compound, 2,2':4,4'':4',4'''-quaterpyridine (Qtpy), C 20 H 14 N 4 , crystallizes in the triclinic P space group and has half of the mol-ecule in the asymmetric unit, corresponding to 4,4'-bi-pyridine (4,4'-bpy) that serves as the building block for the mol-ecule. C 4,4'-bpy -N-C 4,4'-bpy and/or N-C 4,4'-bpy -C 4,4'-bpy bond-angle parameters show that the 4,4'-bpy ligands are highly rigid, displaying values lower than the linear bond angle of 180°. In the crystal, the 4,4'-bpy units are seen to be facing each other in relatively close proximity. The most important inter-actions on the Hirshfeld Surface of the compound are C-H⋯N/H⋯N-C inter-actions (constituting 10.6% and 7.6% of the total surface).