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 image and image. The lattice constants are image, image for In3Ir3B and image, image 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 image, image, image, image) 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.