catena-Poly[[(5,5′-dimethyl-2,2′-bipyridine)nickel(II)]-μ₂-azido-κ² N:N-μ₂-azido-κ² N:N′]: synthesis, crystal structure, Hirshfeld surface analysis and DFT calculations

The title compound, [Ni(N 3 ) 2 (C 12 H 12 N 2 )] n , was synthesized solvothermally and characterized crystallographically. The compound forms a one-dimensional coordination polymer containing alternating spiro-fused four- and eight-membered rings, in which both ring types are centrosymmetric. Adjacent polymer chains are linked into sheets by means of a single C—H...N hydrogen bond. Hirshfeld surface analysis was used to investigate the intermolecular interactions. DFT calculations were used to explore the conformation of the bridging azides and to compare the stability of this compound with those previously reported [Setifi et al. (2022). Acta Cryst . C 78 , 449–454].