Cadmium(II) iodide and thiocyanate complexes adopted by polycyclic 1,4-bis(pyridazin-4-yl)benzene: interplay of coordination and π-π stacking interactions

New complexes containing the 1,4‐bis(pyridazin‐4‐yl)benzene ligand, namely diaquatetrakis[1,4‐bis(pyridazin‐4‐yl)benzene‐κN2]cadmium(II) hexaiodidodicadmate(II), [Cd(C14H10N4)4(H2O)2][Cd2I6], (I), and poly[[μ‐1,4‐bis(pyridazin‐4‐yl)benzene‐κ2N2:N2′]bis(μ‐thiocyanato‐κ2N:S)cadmium(II)], [Cd(NCS)2(C14H10N4)]n, (II), demonstrate the adaptability of the coordination geometries towards the demands of slipped π–π stacking interactions between the extended organic ligands. In (I), the discrete cationic [Cd—N = 2.408 (3) and 2.413 (3) Å] and anionic [Cd—I = 2.709 (2)–3.1201 (14) Å] entities are situated across centres of inversion. The cations associate via complementary O—H...N2′ hydrogen bonding [O...N = 2.748 (4) and 2.765 (4) Å] and extensive triple π–π stacking interactions between pairs of pyridazine and phenylene rings [centroid–centroid distances (CCD) = 3.782 (4)–4.286 (3) Å] to yield two‐dimensional square nets. The [Cd2I6]2− anions reside in channels generated by packing of successive nets. In (II), the CdII cation lies on a centre of inversion and the ligand is situated across a centre of inversion. A two‐dimensional coordination array is formed by crosslinking of linear [Cd(μ‐NCS)2]n chains [Cd—N = 2.3004 (14) Å and Cd—S = 2.7804 (5) Å] with N2:N2′‐bidentate organic bridges [Cd—N = 2.3893 (12) Å], which generate π–π stacks by double‐slipped interactions between phenylene and pyridazine rings [CCD = 3.721 (2) Å].