ChemInform Abstract: Mg_4.85Rh₆Si₁₃, a Magnesium Rhodium Silicide with Silicon Clusters Si₄ and Si₁₈.

Abstract

Mg 4.85Rh6Si13, a Magnesium Rhodium Silicide with Silicon Clusters Si4 and Si18. -Mg 4.85Rh6Si13 is obtained from a melt of the elements in the molar ratio Mg:Rh:Si = 1:1:3 (alumina crucible in Ta ampoule, 1. 790 C, 8 h, 2. 950 C, 12 h). The compound crystallizes in the space group P63/mmc (Z = 4, single crystal XRD) and displays a three-dimensional [Rh 6Si 13] framework which contains Si4 tetrahedra and Mg 2@Si18 polyhedra consisting of 2 Mg-centered truncated tetrahedra connected by a hexagonal face. The compound is a Pauli-paramagnetic "bad metal" with a high electrical resistivity of 46-60 m.