A New Series of Chalcohalide Semiconductors with Composite CdBr2/Sb2Se3 Lattices: Synthesis and Characterization of CdSb2Se3Br2 and Indium Derivatives InSb2S4X (X = Cl and Br) and InM2Se4Br (M = Sb and Bi)

A new series of mixed-framework compounds in the chalcohalide family has been synthesized using the conventional solid-state reactions. These include CdSb2Se3Br2 1 and its isoelectronic indium derivatives InSb2S4X (X = Cl 2 and Br 3) and InM2Se4Br (M = Sb 4 and Bi 5). Single crystals were grown from direct interaction of stoichiometric mixtures of respective elemental and binary compounds. The parent compound cadmium antimony selenobromide, CdSb2Se3Br2, was synthesized by heating the stoichiometric mixture of CdBr2 and Sb and Se at 450 °C followed by slow cooling. Single-crystal structure analysis was carried out by employing X-ray diffraction methods, showing that this compound crystallizes in the monoclinic crystal system (C2/m, No. 12) with a = 20.998(4) A, b = 4.0260(8) A, c = 12.149(2) A, β = 119.00(3)°, and V = 898.3(3) A3. The framework exhibits mixed CdBr2 and Sb2Se3 sublattices, respectively, adopting the (110) and (100) NaCl-type structures. The former consists of dual octahedral chains of Cd-ce...