Exploring Tellurides: Synthesis and Characterization of New Binary, Ternary, and Quaternary Compounds

A fast-growing interest in solid state telluride chemistry has taken place during the past several years. Our research in this area has been primarily on the development and applications of several synthetic techniques that can be applied to the synthesis of the tellurides over a wide temperature range (100-1200°C). These techniques include chemical vapor transport, molten-salt, and hydro(solvo)thermal methods. In this article, we report five binary, ternary, and quaternary metal tellurides, BaTe₂, TaCu₃Te₄, RbTaCu₂Te₄, K₂BaSnTe₄, and K₂Ag₂SnTe₄, synthesized by the molten-salt (alkali-metal polytelluride flux) reactions at intermediate temperatures (400-550°C). The crystal structures of these compounds have been determined by single crystal X-ray diffraction techniques. Crystal data: BaTe₂, space group I4/mcm (No. 140), a = 7.181(1), c = 8.898(2) Å, Z = 4, R1 = 1.55%, wR2 = 3.46%; RbTaCu₂Te₄, space group P2₁cn (No. 33), a = 5.982(2), b = 20.316(3), c = 8.192(2) Å, Z = 4, R1 = 7.13%, wR2 = 4.95%; TaCu₃Te₄, space group P-43m (No. 215), a = 5.930(2) Å,Z = 1, R1 = 2.40%, wR2 = 6.48%; K₂BaSnTe₄, space group I-43m (No. 217), a = 8.393(1) Å, Z = 2, R1 = 2.52%, wR2 = 3.56%; K₂Ag₂SnTe₄, space group I -42m (No. 121), a = 8.732(5), c = 7.425(3) Å, Z = 2, R1 = 3.06%, wR2 = 7.25%.