Macrocyclic amines as structure-directing agents for the synthesis of three-dimensional antimony-sulfide frameworks

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.

A Copper(I)-Thioarsenate(III) Inorganic Framework Directed by [Ni(en)3]2

One novel three-dimensional (3-D) copper(I)-thioarsenate(III) [Ni(en)₃]Cu₄As₄S₉ (1, en = ethylenediamine) has been solvothermally prepared with the utilization of the in situ formation of [Ni(en)₃]²⁺ complex as structure-directing agent (SDA). 1 contains cubane-like [Cu₈S₁₂]^16- clusters and rare tetrameric [As₄S₉]^6- units, which are interconnected to generate the first example of a 3-D anionic framework [Cu₄As₄S₉]_n^2n-, topologically identical to pyrite, and having large channels filled by [Ni(en)₃]²⁺ complex cations. 1 is a potential wide-band-gap semiconductor with an energy gap of 1.91 eV that exhibits selectively photocatalytic degradation of methylene blue under visible-light irradiation. The density functional theory calculation, photocurrent response, and magnetic properties of 1 were also investigated.

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.

Room temperature synthesis, crystal structure and selected properties of the new compound [Mn2(bipy)4SbS4](ClO4)

The new compound [Mn2(bipy)4SbS4](ClO4) was prepared by a new synthetic route for the preparation of thioantimonates(V) that can be used even at room temperature. Mixing aqueous solutions of [Mn(bipy)3](ClO4)2 and Na3SbS4 · 9H2O leads to immediate crystallization of the pure compound. In the structure an SbS4 3– anion acts as a tetradentate bridge connecting two Mn2+ cations of [Mn(bipy)3]2+ complexes (bipy = 2,2′-bipyridine). The compound features a hitherto unknown [Mn2(bipy)4SbS4]+ cation. Bipy ligands of adjacent cations are arranged parallel to each other leading to weak off-center parallel π-π interactions stabilizing the crystals. Magnetic measurements indicate weak antiferromagnetic exchange interactions between the Mn2+ centers.

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.

One-Dimensional Indium Sulfides with Transition Metal Complexes of Polyamines

Three new indium sulfides, [Ni(dien)2]0.5[InS2] (dien = diethylenetriamine) (1), [Ni(dap)3]0.5[InS2] (dap = 1,2-diaminopropane) (2), and [Ni(tepa)]2[In4S7(SH)2].H2O (tepa = tetraethylenepentamine) (3), have been prepared under solvothermal conditions and characterized by single-crystal X-ray diffraction. Compounds 1 and 2 consist of discrete 1-D {[InS2]-} infinity chains with complex cations as charge-compensating ions, while compound 3 consists of a novel 1-D anionic chain constructed from arachno-shaped In4S11 clusters. The sulfide chain of 3 coordinates into the complex cations via the nonterminal S atoms of the polymeric anion, forming a covalently linked organic-inorganic hybrid compound.