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

摘要

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 P (6) over bar 2m and Z = 1. The lattice constants are a = 685.78(l) pm, e = 287.30(l) pm for ln(3)Ir(3)B and a = 678.47(3) pin, 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. In(5)IrqB(4) (hexagonal, space group P (6) over bar 2m, a = 559.0(2) pm, c = 1032.6(3) pm, Z = 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 6(3)) 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. (c) 2006 Elsevier Inc. All rights reserved.