In3Ir3B, In3Rh3B and In5Ir9B4, the first indium platinum metal borides

The first indium platinum metal borides have been synthesized and structurally characterized by single crystal X-ray diffraction data. In3Ir3B and In3Rh3B are isotypic. They crystallize with the hexagonal space group P6¯2m and Z=1Z=1. The lattice constants are a=685.78(1)pm, c=287.30(1)pm for In3Ir3B and a=678.47(3)pm, c=288.61(6)pm for In3Rh3B. The structure which is derived from the Fe2P type is characterized by columns of boron centered triangular platinum metal prisms inserted in a three-dimensional indium matrix. The indium atoms are on split positions. In5Ir9B4 (hexagonal, space group P6¯2m, a=559.0(2)pm, c=1032.6(3)pm, Z=1Z=1) crystallizes with a structure derived from the CeCo3B2 type. The structure can be interpreted as a layer as well as a channel structure. In part the indium atoms are arranged at the vertices of a honeycomb net (Schlaefli symbol 63) separating slabs consisting of double layers of triangular Ir6B prisms, and in part they form a linear chain in a hexagonal channel formed by iridium prisms and indium atoms of the honeycomb lattice.

The crystal structure of In5Ir9B4 (thermal ellipsoid representation; black: Ir, dark gray: B) is derived from the CeCo3B2 type and may be interpreted as a layer as well as a channel structure.Figure optionsDownload as PowerPoint slide