Cationic Pb2 Dumbbells Stabilized in the Highly Covalent Lead Nitridosilicate Pb2Si5N8

Due to the weak oxidative force of N₂, nitrides are only typically formed with the less electronegative metals. Meeting this challenge, we here present Pb₂Si₅N₈, the first nitridosilicate containing highly electron‐affine cations of a metal from the right side of the Zintl border. By using advanced synchrotron X‐ray diffraction, the crystal structure was determined from a tiny single crystal of 1×3×3 μm³ in size, revealing a significantly different bonding situation compared to all other nitridosilicates known so far. Indeed, DFT calculations confirm distinct amounts of covalency not only between Pb and N but also between formal Pb²⁺ cations. Thus, unprecedented cationic Pb₂ dumbbells with a stretching vibration at 117 cm^?1 were found in Pb₂Si₅N₈, the first representative of a crystallographically elucidated lead nitride, stabilized by high amounts of covalency.