RESUMEN
Selective in situ methylation of terminal chalcogenide ligands of molecular chalcogenido metalate anions in ionothermal reactions with alkylimidazolium-based ionic liquids yields a series of organo-functionalized chalcogenido metalate compounds. We present the syntheses and crystal structures of (C4C1C1Im)4+x [Sn10S16O4(SMe)4][An] x (1a-1f), (dmmpH)6[Mn4Sn4Se13(SeMe)4] (2), and (C n C1Im)6[Hg6Te10(TeMe)2] (3a, 3b). The methylation was confirmed by Raman spectroscopy, and the optical absorption properties of the methylated compounds were determined and compared to purely inorganic analogs.
RESUMEN
In order to explore if and how salts comprising polycations and salts comprising polyanions might interact, the [AlBr4 ]- salt of the [Pt@Bi10 ]4+ cluster cation was added to the reaction mixture for the synthesis of the supersphere cluster anion [Ge24 Sn36 Se132 ]24- from Cs4 [Ge4 Se10 ]â H2 O and SnCl4 â 5 H2 O under ionothermal conditions at 120 °C. Indeed, the reaction yields two new compounds, depending on the cation of the used ionic liquid. Apparently, the polycation is not retained under the given conditions, but it acts as a reductant affording SnII . In a (C4 C1 C1 im)+ -based ionic liquid mixture, a unique supertetrahedral anion is obtained that embeds a Cs+ cation, 0D-{[Cs@SnII4 (GeIV4 Se10 )4 ]7- }, while (C4 C1 im)+ cations stabilize an unprecedented ternary layered anion, 2D-{[SnII (GeIV4 Se10 )]2- }. Test reactions with common sources of SnII did not afford the new compounds, indicating the necessity of an in situ reduction, for which the polycation seems appropriate.
RESUMEN
The role of borate anions in ionothermal syntheses of crystalline chalcogenidometalates was shown by the directed ionothermal synthesis of seven new selenidostannates in ionic liquids with either [BF4 ]- or [B(CN)4 ]- anions. Single crystal structures are presented of four compounds, (C4 C1 C1 Im)5 [Sn9 Se20 ][BF4 ] (1, Im=imidazolium), (DMMPH)4 [Sn2 Se6 ] (2, DMMP=2,6-dimethylmorpholine), (C2 C1 Im)2 (DMMPH)2 [Sn6 Se14 ] (3), and K2 [Sn3 Se7 ] (4), and how the chosen ionic liquid anion, and the reaction temperature, influences the product spectrum is discussed: Notably, 1 contains an entire formula unit of the ionic liquid, (C4 C1 C1 Im)[BF4 ], while 4 contains neither the cation nor the anion of the ionic liquid-both observations being very uncommon for ionothermal syntheses. Three further compounds were obtained that exhibit strong disorder in the crystal structures (I-III), for which only their anionic substructures are discussed herein. Compound 4 and I-III are based on the same layered selenidostannate substructure, 2D-{[Sn3 Se7 ]2- }, yet with different inter-layer distances, which is clearly reflected in the crystal colors and quantitative optical absorption properties.
RESUMEN
The synthesis of anionic chalcogenidometalate superspheres can be achieved from [Ge4 Se10 ]4- salts and SnCl4 in ionic liquids with 1-alkyl-(2,)3-(di)methylimidazolium cations, denoted as (Cn (C1 )C1 Im)+ (alkyl = butyl for n=4, hexyl for n=6, octyl for n=8). Their formation is apparently independent from the lengths of the Cn chain, and the presence or absence of a second methyl group at the ionic liquid cation (that are exchanged for alkali metal cations in precursor compounds during the reactions), although this may appear counterintuitive. In contrast, and equally counterintuitive, the ionic liquid anion was found to play a crucial role for both the general observability as well as the crystal yield and quality of the products, although they are not part of the product: a minimum content of chloride is needed, while ionic liquids with [BF4 ]- anions alone do not support the product formation/crystallization. The observation suggests a subtle equilibrium of SnCl4 with according halidostannate anions that decreases the reactivity of the tin source. The finding is of particular interest, as chloride anions were shown to have been major impurities of former "chloride-free" ionic liquid charges, which potentially led to irreproducible synthesis protocols in the literature.
RESUMEN
Crystalline chalcogenides belong to the most promising class of materials. In addition to dense solid-state structures, they may form molecular cluster arrangements and networks with high porosity, as in the so-called "zeotype" chalcogenidometalates. The high structural diversity comes along with interesting physical properties such as semi-/photoconductivity, ion transport capability, molecular trapping potential, as well as chemical and catalytic activity. The great interest in the development of new and tailored chalcogenides has provoked a continuous search for new and better synthesis strategies over the years. The trend has clearly been towards lower temperatures for both economic and ecological reasons as well as for better reaction control. This led to the application of ionic liquids as a designer-like medium for materials synthesis. In this Review, we summarize recent developments and present a survey of different chalcogenide families along with their properties.
RESUMEN
Investigations on the transformation of selenidostannates in ionic liquids were extended by using ternary P1-type cluster precursors [M4Sn4Se17](10-) [M = Mn (1), Zn (2), Cd (3)], which were synthesized for the first time as their Cs(+) salts. Treatment of 1 with 1,2-diaminoethane (en) in [BMIm][BF4] yielded two-dimensional-layered [Mn(en)2.5(en-Me)0.5][Sn3Se7] (4; en-Me = H2NC2H4NHCH3). 1-4 were characterized by single-crystal X-ray diffraction and UV/visible spectroscopy.
RESUMEN
Four new polymeric telluridoindates [K(18-crown-6)][InTe2]·2en (1) (18-crown-6 = 1,4,7,10,13,16-hexaoxacyclooctadecane), [K([2.2.2]crypt)]2[In2Te6]·0.5en (2) ([2.2.2]crypt = 4,7,13,16,21,24-Hexaoxa-1,10-diazabicyclo[8.8.8]hexacosane), [HTMDP]2[In4Te8] (3) (TMDP = 4,4'-trimethylenedipiperidine), and [HDAP]8[In12Te23] (4) (DAP = 1,3-diaminopropane) were prepared from KInTe2 as a starting material. With [InTe4] tetrahedra as the primary building unit in all four compounds, there is a significant increase in complexity in going from the simple chain-like anionic structures in 1 and 2 to an intricate band-type anion in 3 and finally an anionic framework with lig-topology in 4.