Chunying Tang

Heterometallic Clusters [CuSn3S9]5− and [Cu6Sn6S20]10−: Solvothermal Synthesis and Characterization of 4f–3d Thiostannates

Two types of 4f-3d thiostannates with general formula [Hen]₂[Ln(en)₄(CuSn₃S₉)]∙0.5 en (Ln1; Ln=La, 1; Ce, 2) and [Hen]₄[Ln(en)₄]₂[Cu₆Sn₆S₂₀]∙3 en (Ln2; Ln=Nd, 3; Gd, 4; Er, 5) were prepared by reactions of Ln₂O₃, Cu, Sn, and S in ethylenediamine (en) under solvothermal conditions between 160 and 190 °C. However, reactions performed in the range from 120 to 140 °C resulted in crystallization of [Sn₂S₆]⁴⁻) compounds and CuS powder. In 1 and 2, three SnS₄ tetrahedra and one CuS₃ triangle are joined by sharing sulfur atoms to form a novel [CuSn₃S₉]⁵⁻ cluster that coordinates to the Ln(3+) ion of [Ln(en)₄]³⁺ (Ln=La, Ce) as a monodentate ligand. The [CuSn₃S₉]⁵⁻ unit is the first thio-based heterometallic adamantane-like cluster coordinating to a lanthanide center. In 3-5, six SnS₄ tetrahedra and six CuS₃ triangles are connected by sharing common sulfur atoms to form the ternary [Cu₆Sn₆S₂₀ ]¹⁰⁻ cluster, in which a Cu₆ core is enclosed by two Sn₃S₁₀ fragments. The topological structure of the novel Cu₆ core can be regarded as two Cu₄ tetrahedra joined by a common edge. The Ln³⁺ ions in Ln1 and Ln2 are in nine- and eightfold coordination, respectively, which leads to the formation of the [CuSn₃S9]⁵⁻ and [Cu₆Sn₆S₂₀]¹⁰⁻ clusters under identical synthetic conditions. The syntheses of Ln1 and Ln2 show the influence of the lanthanide contraction on the quaternary Ln/Cu/Sn/S system in ethylenediamine. Compounds 1-5 exhibit bandgaps in the range of 2.09-2.48 eV depending on the two different types of clusters in the compounds. Compounds 1, 3, and 4 lost their organic components in the temperature range of 110-350 °C by multistep processes.

Solvothermal syntheses, crystal structures, optical and thermal properties of new selenidogermanate and polyselenidogermanate

AbstractNew selenidogermanate salts [NH 4] 2[H 2N(CH 3) 2] 2Ge 2Se 6 (1) and [Ni(dien) 2] 2Ge 2Se 5(Se 2) (2) (dien = diethylenetriamine), and a selenidogermanate complex [{Ni(tepa)} 2(μ-Ge 2Se 6)] (3) (tepa = tetraethylenepentamine) were prepared by solvothermal reactions. Compounds 1 and 2 consist of discrete [Ge 2Se 6] 4− and [Ge 2Se 7] 4− anions, and NH4+

New μ-SnTe4 and μ-Sn2Te6 ligands to transition metal: Solvothermal syntheses and characterizations of zinc tellurostannates containing polyamine ligands

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Solvothermal Syntheses and Characterizations of Selenidostannate Salts of Transition Metal Complex Cations: Conformational Flexibility of the Lamellar [Sn3Se72–]n Anion†

, [H 2N(CH 3) 2] + and [Ni(dien) 2] 2+ counter cations, respectively. The [Ge 2Se 6] 4− anion is constructed by two tetrahedral GeSe 4 building units via edge-sharing. In 2, two tetrahedral GeSe 4 units are linked by a corner and a Se–Se bond to form a polyselenidogermanate anion [Ge 2Se 7] 4− containing a five-membered ring Ge 2Se 3. The dimeric [Ge 2Se 6] 4− anion acts as a bridging ligand via the trans terminal Se atoms to link two [Ni(tepa)] 2+ cations, resulting in neutral complex 3. The Ni 2+ ion in 2 is coordinated by two tridentate dien ligands, while it is coordinated by a pentadentate tepa ligand and a selenidogermanate anion in 3. The different coordination environments of Ni 2+ ions indicate the influence of the denticity of ethylene polyamines on the formation of selenidogermanates in the presence of transition metal ions. The compounds 1–3 exhibit optical band gaps between 2.06 and 2.35 eV. Graphical AbstractThe syntheses, structural determination,optical and thermal properties of new selenidogermanate salts, [NH4]2[H2N(CH3)2]2Ge2Se6 (1) and [Ni(dien)2]2Ge2Se5(Se2) (2), and a selenidogermanate complex [{Ni(tepa)}2(μ-Ge2Se6)] (3) are reported.