Ba5Cd2Sb4O2—A New Antimonide Oxide with a？Complex Structure

Synthesis and single-crystal X-ray structure determination of the new antimonide oxide, Ba 5Cd 2Sb 4O 2 are reported. Ba 5Cd 2Sb 4O 2 crystallizes in the monoclinic space group C2/m (No. 12) with unit cell parameters: a = 17.247(7) ？, b = 4.9279(18) ？, c = 12.240(5) ？, and β = 132.558(4)°; Z = 2. Its crystal structure can be described as a polyanionic [Cd 2Sb 4] 6– sub-lattice made up of fused CdSb 4 tetrahedra, stacked between puckered slabs of oxo-anions, O 2–, and Ba 2+ cations. This structure can also be described as a “double-salt”, i.e., a structure composed of fragments from the Zintl phase Ba 3Cd 2Sb 4 intercalated by two BaO-like moieties. The topological similarities between the structures of these compounds are discussed.