Three New Thioantimonates(V): Solvothermal Syntheses and Crystal Structures of [M(chxn)3]3(SbS4)2·4H2O (M = Ni, Co) and [Co(dien)2][Co(tren)SbS4]2·4H2O

Synthesis and crystal structure of poly[[di-μ3-tetrathioantimonato-tris[(cyclam)cobalt(II)]] acetonitrile disolvate dihydrate] (cyclam = 1,4,8,11-tetraazacyclotetradecane)

In the crystal structure of the title compound, the [SbS₄]³⁻ anions are linked by the Co(cyclam) complex cations into rings, which are further connected into layers that are linked by inter­molecular hydrogen bonding via the water solvate mol­ecules and are arranged in such a way that cavities are formed, in which the disordered aceto­nitrile solvate mol­ecules are located.

Reaction of Co(ClO₄)₂·6H₂O with cyclam (cyclam = 1,4,8,11-tetra­aza­cyclo­tetra­deca­ne) and Na₃SbS₄·9H₂O (Schlippesches salt) in a mixture of aceto­nitrile and water leads to the formation of crystals of the title compound with the composition {[Co₃(SbS₄)₂(C₁₀H₂₄N₄)₃]·2CH₃CN·2H₂O}_n or {[(Co-cyclam)₃(SbS₄)₂]·2(aceto­nitrile)·2H₂O}_n. The crystal structure of the title compound consists of three crystallographically independent [Co-cyclam]²⁺ cations, which are located on centers of inversion, one [SbS₄]³⁻ anion, one water and one aceto­nitrile mol­ecule that occupy general positions. The aceto­nitrile mol­ecule is disordered over two orientations and was refined using a split model. The Co^II cations are coordinated by four N atoms of the cyclam ligand and two trans-S atoms of the tetra­thio­anti­monate anion within slightly distorted octa­hedra. The unique [SbS₄]³⁻ anion is coordinated to all three crystallographically independent Co^II cations and this unit, with its symmetry-related counterparts, forms rings composed of six Co-cyclam cations and six tetra­thio­anti­monate anions that are further condensed into layers. These layers are perfectly stacked onto each other so that channels are formed in which acetontrile solvate mol­ecules that are hydrogen bonded to the anions are embedded. The water solvate mol­ecules are located between the layers and are connected to the cyclam ligands and the [SbS₄]³⁻ anions via inter­molecular N—H⋯O and O—H⋯S hydrogen bonding.

The cation and anion bonding modes make a difference: an unprecedented layered structure and a tri(hetero)nuclear moiety in thioantimonates(V)

Mixing solutions of M²⁺ (M = Cu²⁺ or Zn²⁺) salts containing cyclam (cyclam = 1,4,8,11-tetraazacyclotetradecane) as the ligand and an aqueous solution of Na₃SbS₄·9H₂O at room temperature led to the crystallization of two new compounds within minutes: {[Cu(cyclam)]₃[SbS₄]₂}_n·20nH₂O (I) and {[Zn(cyclam)]₃[SbS₄]₂}·8H₂O (II). In the structure of I [SbS₄]^3- anions acting as a tridentate ligand join CuN₄S₂ octahedra generating twelve-membered rings by corner-sharing of SbS₄ and CuN₄S₂ units. The rings are condensed into layers, which are stacked onto each other in a 6R polytype manner. The layers contain large pores with the water molecules located between the layers above and below the pores. In contrast, the structure of II comprises a discrete molecular tri(hetero)nuclear moiety with a bidentate [SbS₄]^3- anion connecting two rectangular pyramidal ZnN₄S polyhedra. The crystal water molecules of I and II can be thermally removed, and I and II are recovered by treatment under a humid atmosphere. The EPR spectrum of I indicates the presence of Cu²⁺ cations, which is unusual in the environment of S^2- anions. The different bonding situations and the preferences for the coordination geometries of Cu²⁺ and Zn²⁺ cations are rationalized by DFT based calculations, demonstrating that Cu²⁺ prefers an octahedral environment while Zn²⁺ adopts the square-pyramidal coordination. The pronounced differences in the vibrational spectra are also analyzed with DFT, showing how the different modes are influenced by the differing bond strengths.

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.

Utilization of mixtures of aromatic N-donor ligands of different coordination ability for the solvothermal synthesis of thiostannate containing molecules

Utilization of mixtures of differently coordinating aromatic N-donor ligands leads to the formation of the two new compounds {[Ni(phen)2]2Sn2S6}·4,4'-bipy·½H2O I and {[Ni(phen)2]2Sn2S6}·2,2'-bipy II that could be prepared under solvothermal conditions (4,4'-bipy = 4,4'-bipyridine, C10H8N2; phen = 1,10-phenanthroline, C12H8N2; 2,2'-bipy = 2,2'-bipyridine, C10H8N2). In the structures of both compounds Ni-S bond formation is observed which is highly unusual when only bidentate N-donor ligands are applied in the reaction mixture. The detailed analysis of the crystal structure indicates that the presence of 4,4'-bipy and 2,2'-bipy molecules are essential for the stabilization of the arrangement of the constituents. The main structural motif {[Ni(phen)2]2Sn2S6} is arranged generating off center parallel stacking of the phen ligands. The empty spaces between the {[Ni(phen)2]2Sn2S6} moieties are occupied by either 2,2'-bipy (I) or 4,4'-bipy (II) molecules which are oriented towards the phen ligands to form intermolecular π-π interactions.

Interplay of ligand chirality and metal configuration in mononuclear complexes and in a coordination polymer of Cr(iii)

Chiral information may be transferred from a ligand to the coordinated chromium cation. The resulting complex can be crosslinked with a Ag(i) salt to a mixed-metal polymer with well-defined configuration at the Cr(iii).

Two manganese–amine complexes incorporating thioantimonates and exhibiting diversiform roles of amine ligands

Two manganese–amine complexes incorporating thioantimonates with diversiform structure-directing actions of the amine ligands have been synthesized and characterized.