Darstellung und Kristallstruktur der ternären Boride SrNi₁₂B₆ und BaNi₁₂B₆

Abstract

Abstract The crystal structures of the newly prepared ternary borides SrNi 12 B 6 and BaNi 12 B 6 have been determined by single-crystal X-ray methods and refined to R -values of 0.031 and 0.052 respectively. Both compounds crystallize in space group R[unk]m–D 5 3d with lattice constants a = 959.0 pm, c = 745.5 pm, Z = 3 for SrNi 12 B 6 and a = 968.9 pm, c = 747.0 pm, Z = 3 for BaNi 12 B 6 . The structure contains isolated boron atoms, surrounded by distorted trigonal prisms of Ni atoms with one additional Ni upon one of the faces. The prisms are arranged in connected layers consisting of six- and three-membered rings. Of the compounds SrNi 2 B 2 , BaNi 2 B 2 , and Ba 2 Ni 9 B 6 lattice constants are reported.