Cs₁₀H[Ga₃H₈]₃: A Hydrogenous Zintl phase Containing Propane-Like Polyanions [Ga₃H₈]^3– and Interstitial Hydrogen

The hydrogenous Zintl-phase Cs₁₀H­[Ga₃H₈]₃ containing propane-like polyanions [Ga₃H­(D)₈]^3– was successfully synthesized by direct hydrogenation of a 1:1 Cs/Ga metal mixture and characterized by powder X-ray and neutron diffraction. The charge of the polyanions is balanced by two different species of cations, hydrogen-centered octahedra [H­(D)­Cs₆]⁵⁺ and isolated Cs⁺. The structure crystallizes in the hexagonal space group P6₃/mcm (193) with the cell parameters a = 11.1108(3) Å, c = 18.2149(5) Å, Z = 2.