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.