The antimonides Ce2Ir3Sb4, La2Ir3Sb4, and Ce2Rh3Sb4 were synthesized by solid state reaction from the elements. The crystal structures of these compounds were determined from single crystal X-ray diffraction data. Ce2Ir3Sb4 crystallises in a new structure type in the space group Pnma (no. 62) with a = 16.1510(8) Å, b = 4.5600(3) Å, c = 10.9463(5) Å. La2Ir3Sb4 and Ce2Rh3Sb4 crystallise in the Ce2Ir3Sb4 structure type as well with a = 16.2659(10) Å, b = 4.5896(3) Å, c = 10.9996(7) Å) and a = 16.2293(8) Å, b = 4.5604(2) Å, c = 10.9804(5) Å, respectively. The four- and five-bonded transition metal atoms and three- and four-bounded Sb atoms form a 3D-network with the rare-earth metal embedded in its cavities, resembling the topology of Ca in the CaBe2Ge2 or Th in ThCr2Si2 type. Magnetic susceptibility and X-ray absorption near edge spectroscopy data indicate a stable trivalent state for Ce in the Ce2Ir3Sb4 compound.
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