A mixed-anion compound based upon a [Pb4O4] heterocubane unit: synthesis, structure and electronic properties of Pb8O4I6(CN2)

Abstract

The present study reports the synthesis, crystal structure, and electronic properties of the lead–oxide–iodide–carbodiimde Pb₈O₄I₆(CN₂). The n-type semiconducting compound was obtained via ceramic method from PbI₂, PbO and Pb(CN₂), yielding an air stable, dark yellow crystalline material. Single-crystal X-ray diffraction revealed the monoclinic space group C2/c featuring a heterocubane-type [Pb₄O₄] motif interconnected by iodide bridges and (NCN)²⁻ units. The optical properties were characterized by diffuse reflectance UV-Vis spectroscopy, Mott–Schottky analysis, and photoluminescence spectroscopy, providing insights into the electronic structure.