RbLi(NH2)2, a Rubidium Amido Lithiate Investigated by X‐Ray and Neutron Diffraction

RbLi(NH₂)₂ and the fully deuterated compound are obtained in autoclaves by the reaction of RbNH₂/RbND₂ and Li metal in supercritical NH₃/ND₃ (470 K, 220 Mpa, 41 d). X‐ray single crystal and neutron powder diffraction led to a new type of crystal structure closely related to the ThCr₂Si₂type. It is an orthorhombic distorted variant with an ordered half occupation by lithium on tetrahedral sites of puckered 4⁴ nets of amide ions to{Li(NH₂)_1/1(NH₂)_3/3]} units and fully filled up sites of CN = 8 by Rb. The compound crystallizes in the space group Pnma with Z = 4 and a = 7.772 (2)Å, b = 3.843 (1)Å, c = 11.583 (2)Å. It contains an unexpected hydrogen bridge bonding system between crystallographic different amide ions.