Selenidostannates and a Silver Selenidostannate Synthesized in Deep Eutectic Solvents: Crystal Structures and Thermochromic Study

Abstract

Deep eutectic solvents (DESs) have been adopted as reaction media for solvothermal synthesis of crystal materials. In the present work, we extended the scope of DESs in chalcogenidometalate preparation by including dimethylamine, ethylamine, and trimethylamine hydrochlorides and synthesized a series of novel Sn-Se and Ag-Sn-Se compounds: i.e., [NH2(CH3)2]2Sn3Se7·0.5NH­(CH3)2 (1), [NH4]2Sn4Se9 (2), [NH3C2H5]2Sn3Se7 (3), and [NH4]3AgSn3Se8 (4). Compounds 1 and 3 possess honeycomb lamellar [Sn3Se7] n 2n– structures featuring large hexagonal windows, while compound 2 features a rare [Sn4Se9] n 2n– anionic layer consisting of tetrameric {Sn4Se10} clusters as secondary building units (SBUs). Compound 4 comprises infinite [AgSn3Se8] n 3n– chains built by {Sn3Se8} units with Ag+ linkers, and it represents the first heterometallic chalcogenide synthesized in DESs. The organic ammonium cations of halide salts or in situ formed ammonium cations from the decomposition of urea act as templating agents for the formation of the inorganic frameworks. Compound 4 exhibits a marked thermochromic performance in the visible light range owing to the negative temperature dependence of its band gap (E g = 2.305–2.119 eV in the range of 100–450 K). The gold−dark red−gold color change is highly reversible in five rounds of heating and cooling, without any phase transition of the material, shedding light on the consequent device innovations.

pH‐Controlled Switch over Coadsorption and Separation for Mixed Cs+ and Sr2+ by an Acid‐Resistant Potassium Thioantimonate

“…[ 51,52 ] Besides, the hydrolysis of urea during the reaction offers ammonium cations as both templating and charge‐balancing agents to construct the anionic ribbon‐stacking lattice of SbS‐1 with appropriate channels responsible for the ion transfer and fixation. [ 53,54 ] Two parameters need to be finely tuned for synthetic optimization. 1) The synthesis for SbS‐1 requires a temperature above 180 °C, as lower temperatures lead to obviously reduced yield (Figures S2 and S3, Supporting Information).…”

Ionic liquids and deep eutectics as a transformative platform for the synthesis of nanomaterials

“…272 273 Various nanoporous (silver) selenidostannates were prepared by Wang et al from eutectic mixtures of alkylamine hydrochlorides, with interesting tuneable properties such as reversible thermochromism. 274 It has been shown that the choice of DES strongly dictates the growth process. 275 Even sheet and flower-like nanostructured hierarchical intermetallic nitro-sulfide compounds have been synthesised: Here, mixed-metallic DESs containing FeCl 3 .6H 2 O, CoCl 2 .6H 2 O and NiCl 2 .6H 2 O were directly annealed at 350 °C for 12 hours.…”

Conversion of Organically Directed Selenidostannate into Porous SnO2 Exhibiting Effective Electrochemical Reduction of CO2 to C1 Products

“…27,28 This contributes to a more efficient and faster synthesis for selenidostannate within hours compared to those conducted in neutral, volatile organic solvents (e.g., ethanol and dimethylformamide, DMF). 29,30 Besides, the choline component of DES acts as significant templates and counter cations that account for the construction of honeycomb-like [Sn 3 Se 7 ] n 2n− layers, whose parallel stacking gives the final hybrid of Ch-Sn 3 Se 7 (Figure 2). In the crystal lattice, all of the choline templates exhibit the same activation energy for release/decomposition in response to external thermal stimuli, implying that they can be precisely removed upon heating to a certain temperature.…”