Solid‐State Preparation and Luminescence Investigation of Rare Earth Iodide Carbodiimide Nitrides RE2I(CN2)N (RE = La, Gd) and LaI(CN2)

New rare earth iodide carbodiimide nitride compounds with the composition RE2I(CN2)N (RE = La, Gd) were successfully synthesized by multilateral solid‐state metathesis reaction from RE triiodides, LiN and Li2(CN2). The crystal structures of RE2I(CN2)N were refined from X‐ray powder diffraction data with the space group Cmmm. LaI(CN2) was prepared from a mixture of LaI3 and Li2(CN2). The crystal structure was determined by X‐ray single‐crystal diffraction on a colorless crystal with the orthorhombic space group Cmcm. The luminescence investigation of Ce3+‐doped LaI(CN2) was carried out by excitation at 390 nm and reveals a broad emission band in the blue range of the visible spectrum. New rare earth iodide carbodiimides La2I(CN2)N, Gd2I(CN2)N, and LaI(CN2), synthesized by solid‐state metathesis reactions are reported with their crystal structures. The emission spectrum of LaI(CN2):Ce shows an intensive broad emission of Ce3+ under excitation at 390 nm.