Room-Temperature Synthesis of Thiostannates from {[Ni(tren)]₂[Sn₂S₆]}_n

The compound {[Ni­(tren)]₂[Sn₂S₆]}_n (1) (tren = tris­(2-aminoethyl)­amine, C₆H₁₈N₄) was successfully applied as source for the room-temperature synthesis of the new thiostannates [Ni­(tren)­(ma)­(H₂O)]₂[Sn₂S₆]·4H₂O (2) (ma = methylamine, CH₅N) and [Ni­(tren)­(1,2-dap)]₂[Sn₂S₆]·2H₂O (3) (1,2-dap = 1,2-diaminopropane, C₃H₁₀N₂). The Ni–S bonds in the Ni₂S₂N₈ bioctahedron in the structure of 1 are analyzed with density functional theory calculations demonstrating significantly differing Ni–S bond strengths. Because of this asymmetry they are easily broken in the presence of an excess of ma or 1,2-dap immediately followed by Ni–N bond formation to N donor atoms of the amine ligands thus generating [Ni­(tren)­(amine)]²⁺ complexes. The chemical reactions are fast, and compounds 2 and 3 are formed within 1 h. The synthesis concept presented here opens hitherto unknown possibilities for preparation of new thiostannates.