Efficient Synthesis and Properties of Single‐Crystalline [SnTe4]4− Salts

Single‐crystalline K⁺, Rb⁺, and Cs⁺ salts of the ortho‐tellurostannate anion have been prepared by a very efficient fusing/extraction/evaporation method. The resulting compounds with the general composition A₄(H₂O)_n]SnTe₄] can be transferred into mixed H₂O/en solvates by solving the hydrates in 1,2‐diaminoethane (en) and ensuing layering by toluene. A mixed Rb⁺/Ba²⁺ salt results from a partial cation exchange of the Rb⁺ hydrate phase in solution. All hydrates react to polytellurides when exposed to air and represent useful starting materials for the synthesis of transition metal complexes with SnTe₄]^4? groups as binary main group elemental ligands. K₄(H₂O)_0.5]SnTe₄] ( 1 ), Rb₄(H₂O)₂]SnTe₄] ( 2 ), Cs₄(H₂O)₂]SnTe₄] ( 3 ), K₄(H₂O)(en)]SnTe₄] ( 4 ), Rb₄(H₂O)_0.67(en)_0.33]SnTe₄] ( 5 ), Cs₄(H₂O)_0.5(en)_0.5]SnTe₄] ( 6 ), and Rb₂Ba(H₂O)₁₁]SnTe₄] ( 7 ) were characterized by means of X‐ray diffractometry and optical absorption spectroscopy.