High‐Pressure Synthesis and Characterization of the Alkali Diazenide Li2N2

Diazenide surprise: The synthesis of an alkali diazenide, Li2N2, is presented. Lithium diazenide adopts an unprecedented structure type for compounds with A2B2 composition (see picture). Spectroscopic analysis shows a significant feature at 1328 cm−1 which is assigned to the stretching vibration of the [N2]2− ion. Electronic structure calculations underline the metallic character and confirm the 50 % occupation of the antibonding π states in [N2]2−.