[(H2en)7(C2O4)2]n(Pb4I18)n.4nH2O, a new type of perovskite co-templated by both organic cations and anions.

A novel inorganic-organic hybrid [(H2en)7(C2O4)2]n(Pb4I18)n.4nH2O has been synthesized by employing an organic anionic-cationic co-template. It shows a new type of perovskite structure, featuring an unprecedented staircase-like inorganic network. The title compound exhibits an intriguing semiconducting property with Eg = 2.47 eV and strong photoluminescence arising from band-edge transitions.