High‐Pressure Synthesis of Ultra‐Incompressible Beryllium Tungsten Nitride Pernitride BeW ₁₀ N ₁₄ (N ₂ )

For the activation of nitrogen and its reduction to ammonia, transition metals are crucial in biological as well as industrial processes. So far, only a few binary transition metal compounds with nitrogen dimer anions are known, whereas a ternary compound has remained undiscovered as yet. Here, we report on the synthesis and properties of the first ternary transition metal compound, namely, BeW₁₀N₁₄(N₂), which exhibits dinitrogen anions. It was synthesized in a high-temperature high-pressure approach from W₂Be₄N₅. The crystal structure, elucidated with synchrotron radiation, unites WN₇ capped trigonal prisms with intriguing BeN₆ octahedra and (N₂)-anions. Elastic and electronic properties of the title compound were corroborated by DFT calculations, revealing simultaneous ultra-incompressible and metallic behavior. The synthesis and investigation of the first ternary transition metal nitride with dinitrogen units opens the door to a new field of research on nitride and pernitride chemistry.