Hydrazine-Assisted Synthesis, Structures, Photoelectricity, and Photocatalysis of Ternary Mercury-Tellurostannate Hybrids with Transition-Metal Complexes

Tellurostannates are traditionally prepared by multistep reactions using the tellurides SnTe, SnTe2, K4SnTe4, or A6SnTe6 (A = K, Rb, or Cs) as precursors, which are usually prepared by the molten reaction of alkali metals Sn and Te under harsh synthetic conditions. Differently, ternary Hg-tellurostannate hybrids [Mn(en)3]HgSnTe3(Te2) (1) (en = ethylenediamine), [Mn(dien)2]HgSnTe3(Te2) (2), and [Fe(dien)2]HgSnTe3(Te2) (3) (dien = diethylenetriamine) were synthesized by one-pot reactions using Sn and Te powders as starting materials in the presence of hydrazine under mild solvothermal conditions. In 1, HgTe3 and SnTe4 units are joined via Te-sharing to form a 1-D polymeric chain [HgSnTe3(Te2)]n2n-, while the [HgSnTe3(Te2)]n2n- chains in 2 and 3 are composed of HgTe4 and SnTe4 units. The common feature of the [HgSnTe3(Te2)2-]n chains in 1-3 is that they are constructed by both the telluride anion Te2- and the polytelluride anion Te22-. 1-3 exhibited strong photocurrent responses with current densities of 5.26, 3.38, and 3.94 μA cm-2, respectively. They showed effective photocatalytic activities for methylene blue degradation with degradation ratios in the range of 85.3-94.6% after light irradiation for 80 min. Investigation of the photocatalytic mechanism showed that •O2- radicals and h+ holes were the main active substances in the photodegradation.

Selective and benign alkylation of sulfido-oxo stannate clusters with propyl, pentyl, or hexyl substituents

Chalcogenido metalate compounds that are based on tetrahedral clusters have been extensively studied in recent years due to their rich structural chemistry and uncommon chemical and physical properties. Recently it was shown that partial butylation of the inorganic cluster core by ionothermal reactions allowed access to tetrahedral sulfido-oxo stannate clusters with reasonable solubility in conventional solvents at the retainment of their opto-electronic features. We have expanded this mild alkylation approach, and herein report success in receiving the first sulfido-oxo stannate clusters that are selectively propylated, pentylated, and hexylated. This was achieved in a unique way by preparing symmetrically 1,3-substituted imidazolium bromides in preparative scale and using them as both the reaction medium and alkylatoin reagent. We discuss the effect of the organic groups attached to the cluster and present in the counterions of the products on the compounds' structural and opto-electronic properties.

Crystalline chalcogenidometalate-based compounds from uncommon reaction media

Chalcogenides are one of the most versatile inorganic materials families, further subdivided into a large variety of specific groups of compounds, ranging from neat binary or multinary solids and nanoparticles of the same formal compositions, both in crystalline or non-crystalline form, to complicated open-framework structures and cluster compounds, also including organ(ometall)ic derivates of the latter. The large variety regarding both the compositions and the structures is associated with an enormous variety of properties, ranging from simple or high-tech pigments through a multitude of opto-electronic devices and electrolytes to materials for ion separation or high-sophisticated catalysts. Naturally, this also goes hand in hand with a corrosponding breadth of synthesis strategies. Traditionally, chalcogenides have been accessed via high-temperature methods, which continuously have been replaced by lower-temperature approaches for economical and ecological reasons. Moreover, more recent methods also showed that new types of chalcogenide materials can be obtained under such milder conditions that are not accessible via traditional routes. To shed light onto one of the numerous families of chalcogenides, this feature article summarizes current achievements in the generation of multinary chalcogenidometallate-based clusters and networks via non-classical routes, using ionic liquids, surfactants, or hydrazine as reaction media at moderately elevated termperature.

Recent Advance in Ionic-Liquid-Based Electrolytes for Rechargeable Metal-Ion Batteries

From basic research to industry process, battery energy storage systems have played a great role in the informatization, mobility, and intellectualization of modern human society. Some potential systems such as Li, Na, K, Mg, Zn, and Al secondary batteries have attracted much attention to maintain social progress and sustainable development. As one of the components in batteries, electrolytes play an important role in the upgrade and breakthrough of battery technology. Since room-temperature ionic liquids (ILs) feature high conductivity, nonflammability, nonvolatility, high thermal stability, and wide electrochemical window, they have been widely applied in various battery systems and show great potential in improving battery stability, kinetics performance, energy density, service life, and safety. Thus, it is a right time to summarize these progresses. In this review, the composition and classification of various ILs and their recent applications as electrolytes in diverse metal-ion batteries (Li, Na, K, Mg, Zn, Al) are outlined to enhance the battery performances.

Two Series of Main-Group Heterometallic Selenides Synthesized in Two Different Types of Ionic Liquids

Imidazolium-based ionic liquids have been widely applied in the synthesis of organic hybrid chalcogenidometalates, while the other types of ionic liquids are rarely tried. Reported here is the first application of a pyridinium-based ionic liquid in the preparation of two main-group heterometallic selenides featuring isomorphic three-dimensional frameworks. Of particular interest is that three gallium-tin selenides possessing another type of three-dimensional framework have been prepared by replacing the pyridinium-based ionic liquid with imidalolium-based ionic liquids under the same reaction conditions.

Coupling an organic photosensitizer and an inorganic framework into a single-phase material that shows visible-light photocurrent response

A rare hybrid of a 3D Sn–Se type framework and a ruthenium(ii) photosensitizer has been synthesized, and exhibits visible light photocurrent response.

Synthesizing Crystalline Chalcogenidoarsenates in Thiol-Amine Solvent Mixtures

Thiol-amine solvent mixtures have been widely applied in the solution processing of binary chalcogenide thin films due to their excellent ability to dissolve various bulk binary chalcogenides. However, application of this solvent system in preparing new crystalline chalcogenidometalates has not been explored. In this work, by using a thiol-amine solvent mixture of n-butylamine (BA) and 1,2-ethanedithiol (EDT) as the reaction medium and protonated piperazine (pip) cation as the template, we synthesized a series of new chalcogenidoarsenates with structures ranging from discrete clusters to two-dimensional layers, namely, [pipH₂][pipH][AsS₄] (1), [pipH₂][pipH][As(Se_0.4S_0.6)₄] (2), [pipH₂]₂[pipH]₂[In₂As^III₂As^V₂S_13.3(S₂)_0.7] (3), [pipH₂]₂[pipH]₂[In₂As^III₂As^V₂S_10.2Se_3.1(Se₂)_0.7] (4), [pipH₂]_0.5[AsS(S₂)] (5), [pipH₂]_0.5[AsS₂] (6), [pipH]₂[AgAsS₄] (7), [pipH₂]_1.5[GaAs^IIIAs^VS₇] (8), and Cs₂[pipH]₂[InAs₆S₁₂]Cl (9). Particularly, compounds 3, 4, and 8 contain mixed-valent As^III and As^V ions in their discrete clusters and one-dimensional chain. In addition, compound 5 could thermodynamically transform to compound 6 with increasing reaction temperature, which may be attributed to the thermodynamically unstable S-S species in the chains of 5. The BA-EDT solvent mixture was crucial to the synthesis of these compounds, since no title crystals can be prepared by replacing the BA-EDT solvent mixture with other conventional solvents or removing one component of the BA-EDT solvent mixture from the reaction system. Our research demonstrates that thiol-amine solvent systems could be promising reaction media for growing novel crystalline chalcogenidometalates.

Alcohol-solvothermal syntheses, crystal structures and photocatalytic properties of tin selenides with polyselenide ligands

New polyselenidostannates with Se₂²⁻ or Se₄²⁻ polyselenide ligands, [TM(en)₃]Sn₃Se₆(Se₂) (1–3), [Ni(en)₃]Sn₃Se_7.5 (4) and [TM(en)₃][Sn(Se₄)₃] (5–8), were prepared by alcohol-solvothermal methods.

Hydrazine-solvothermal methods to synthesize polymeric thioarsenates from one-dimensional chains to a three-dimensional framework

A series of polymeric Mn(ii)-thioarsenates [Mn(en)₃]_n[(N₂H₄)₂Mn₆(μ₆-S)(μ-N₂H₄)₂(μ₃-AsS₃)₄]_n (1), [N₂H₅]_n[{Mn(μ-N₂H₄)₂(μ-AsS₄)}·0.5en]_n (2), [Mn(μ-trien){Mn(μ-N₂H₄)(μ-AsS₃)}₂]_n (3), [{Mn(N₂H₄)}₂(μ-N₂H₄)₂{Mn(μ-N₂H₄)₂(μ-AsS₃)₂}]_n (4), [Mn₃(μ-N₂H₄)₆(μ₃-AsS₄)(μ₂-AsS₄)]_n (5), and [Mn(NH₃)₆]_n[{Mn(NH₃)(μ-AsS₄)}₂]_n (6) were synthesized using a hydrazine-solvothermal method. The thioarsenate units AsS₃ and AsS₄ coordinate to Mn(ii) ions with variable coordination modes, forming a Mn–As–S ternary cluster (1), chains (2, 4–6), and layers (3), respectively. The hydrazine molecules act as inter-cluster, intra-chain and intra-layer bridging ligands to join the Mn(ii) ions, resulting in hydrazine hybrid 1-D, 2-D, and 3-D Mn(ii)-thioarsenate moieties in 1–5. Compounds 1–6 exhibit tunable semiconducting band gaps varying in the range of 2.19–2.47 eV. Compound 1 displays stronger antiferromagnetic coupling interactions than that of compound 2.

Mn(ii)-thioarsenates [Mn(en)₃]_n[Mn₆S(N₂H₄)₄(AsS₃)₄]_n (1), [N₂H₅]_n[{Mn(N₂H₄)₂(AsS₄)}·0.5en]_n (2), [Mn(trien){Mn(N₂H₄)(AsS₃)}₂]_n (3), [Mn₃(N₂H₄)₆(AsS₃)₂]_n (4), [Mn₃(N₂H₄)₆(AsS₄)₂]_n (5), and [Mn(NH₃)₆]_n[{Mn(NH₃)(AsS₄)}₂]_n (6) were prepared in N₂H₄ by solvothermal methods.