ChemInform Abstract: Ca₅₄In₁₃B_4‐xH_23+x: A Complex Metal Subhydride Featuring Ionic and Metallic Regions.

Abstract

Regions. -Ca 54In13B4-xH23+x (2.4 < x < 4) is prepared by solid state reactions of Ca, Li, In, B, and CaH 2 in the molar ratio of 10:10:1:1:1, resp., using Ca and Li as a flux (stainless steel container in evacuated silica tube, 1050 C, 2 h; controlled cooling). The compound crystallizes in the cubic space group Im3 (Z = 2, single crystal XRD) and exhibits a complex new structure comprising a body-centered cubic array of Bergman--related clusters that are composed of a central In atom surrounded by an icosahedron of 12 Ca atoms; Hions cap each face forming a pentagonal dodecahedron that is further surrounded by a Ca shell. These In@Ca 12@H20@Ca30 clusters are surrounded by a disordered Ca In hydride network. Indium appears to be not completely reduced by the flux, as the structure features ionic hydride regions and metallic Ca In regions. The compound can therefore be viewed as a "subhydride" akin to the alkali metal suboxides that feature ionic oxide clusters surrounded by metallic regions. -(BLANKENSHIP, T. V.; CHEN, B.; LATTURNER*, S. E.; Chem. Mater. 26 (2014) 10, 3202-3208, http://dx.