A carbazole-based triple bridging ligand (LH) consisting of two imidazole moieties with a diketone unit forms carbazole-bridged zinc(ii) complexes with structures of [(L−)4(Zn2+)n] (n = 2–6), where the strength of aromatic stacking interactions between the carbazole rings increases with an increase in the number of Zn2+ ions bridged.