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

Abstract

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.

New Transition Metal Oxo‐Thiostannate: Synthesis, Characterization, and Investigation of its Photocatalytic Properties

“…The μ 3 ‐O‐Sn bonds are between 2.075(5) and 2.128(5) Å. Similar values have also been reported in literature , , , , . The Sn–OH bond lengths range from 2.066(6) to 2.102(6) Å and are significantly shorter than for bridged OH – anions (2.310 and 2.348 Å) (Figure S2, Supporting Information).…”

“…Four empty sites are occupied by O 2– anions expanding the coordination number of Sn from four to five or six , , . All Sn‐O‐S compounds contain isolated [Sn 10 S 20 O 4 ] 8– anionic clusters with inorganic cations compensating the negative charges like in [Cs 8 (H 2 O) 13 ][Sn 10 S 20 O 4 ] and [Li 8 (H 2 O) 29 ][Sn 10 S 20 O 4 ] · 2H 2 O, and only in {[Ni(1,2‐dach) 2 (ma)] 4 [Sn 10 S 20 O 4 ]} (1,2‐dach = 1,2‐diaminocyclohexane; ma = methylamine) the cluster is expanded via sulfur atoms to Ni 2+ centered complexes.…”

Room Temperature Synthesis of New Thiostannates by Slow Interdiffusion of Different Solvents

“…The Ni1-S bond length is at 2.6444(8) Å which is longer than the sum of ionic radii of 2.53 Å (Ni 2+ CN6 = 0.69 Å; S 2-: 1.84 Å). [36] Comparable Ni-S bonds were observed for {[Ni(cyclam)] 2 [Sn 2 S 6 ]} n •2nH 2 O, [5] [Ni(pda) 2 ][Cu 4 Sb 2 S 6 ] (pda = 1,2-propanediamine), [37] [Ni(tren)][Sb 2 S 4 ], [38] [39] [5] We note that the second terminal S 2of the anion is 3.14 Å apart from the Ni 2+ cation in the square-pyramidal environment of L 1 . But this distance is too long for significant bonding interactions.…”

Transition Metal Complexes with Linkage to the Thiostannate Units Forced by Suitable Amine Molecules

“…The charge compensation in these compounds can be achieved in different ways: (a) inorganic cations, (b) inorganic‐organic hybrid compounds with protonated amine molecules as counterions, (c) compounds with integrated transition metal ions (TM) in the thiostannate unit and protonated amines as counterions, and finally (d) compounds containing [TM(amine) n ] m + or [ Ln (amine) n ] m + complexes for charge compensation as summarized in several review articles , , . In the latter group mainly the [Sn 2 S 6 ] 4– unit is observed, whereas the [SnS 4 ] 4– anion is less common , , , . Other thiostannate ions like for example [Sn 3 S 7 ] 2– , [Sn 4 S 9 ] 2– ,, [Sn 5 S 12 ] 4– , [Sn 3 S 9 ] 6– , or [Sn 4 S 10 ] 4– are only found in pure inorganic or inorganic‐organic hybrid compounds so far.…”

“…The remaining cations mentioned above exhibit an obviously higher affinity towards N, and bond formation to S atom(s) has to be enforced by synthetic tricks, e.g. using amines like tetraethylenepentamine (tepa) in {[Ni(tepa)] 2 [Sn 2 S 6 ]}, or tris(2‐aminoethyl)amine (tren) in {[Ni(tren)] 2 [Sn 2 S 6 ]} n , which cannot saturate the coordination sphere of the central metal atom. Aromatic or cyclic amines with rigid positions of the amine groups like 1,10‐phenanthroline (phen) in {[TM(phen) 2 ] 2 [Sn 2 S 6 ]} · (TM = Fe, Co), and {[Ni(phen) 2 ] 2 [Sn 2 S 6 ]} · amine (amine = 2,2′‐bipyridine (2,2′‐bipy), 4,4′‐bipyridine (4,4′‐bipy)) and 1,2‐diaminocyclohexane (1,2‐dach) in the related class of thioantimonates in {[Fe(1,2‐dach) 2 ][Sb 6 S 10 ]} seem to be exceptions: in principal these amine ligands could satisfy the coordination requirements of the central TM 2+ atoms, but interestingly TM–S bonds have been observed, even with Fe 2+ and Co 2+ which normally prefer bonds to N donor ligands.…”