High-Pressure Synthesis of Ultra-Incompressible Beryllium Tungsten Nitride Pernitride BeW10N14(N2).

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.