Bridgman crystal growth of Yb 2Ru 3Ge 4—A ternary germanide with a three-dimensional network of condensed distorted RuGe 5 and RuGe 6 units

Abstract

The germanide Yb 2Ru 3Ge 4 was synthesized from the elements using the Bridgman crystal growth technique. The monoclinic Hf 2Ru 3Si 4 type structure was investigated by X-ray powder and single crystal diffraction: C2/ c, Z=8, a=1993.0(3) pm, b=550.69(8) pm, c=1388.0(2) pm, β=128.383(9)°, w R 2=0.0569, 2047 F 2 values, and 84 variables. Yb 2Ru 3Ge 4 contains two crystallographically independent ytterbium sites with coordination numbers of 18 and 17 for Yb1 and Yb2, respectively. Each ytterbium atom has three ytterbium neighbors at Yb–Yb distances ranging from 345 to 368 pm. The shortest interatomic distances occur for the Ru–Ge contacts. The three crystallographically independent ruthenium sites have between five and six germanium neighbors in distorted trigonal bipyramidal (Ru1Ge 5) or octahedral (Ru2Ge 6 and Ru3Ge 6) coordination at Ru–Ge distances ranging from 245 to 279 pm. The Ru2 atoms form zig-zag chains running parallel to the b-axis at Ru2–Ru2 of 284 pm. The RuGe 5 and RuGe 6 units are condensed via common edges and faces leading to a complex three-dimensional [Ru 3Ge 4] network.