Darstellung und Kristallstrukturen von Li4−2xSr2+xB10S19 (x ≈ 0,27) und Na6B10S18. Zwei neue Thioborate mit hochpolymeren Makrotetraeder-Netzwerken |
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Authors: | A. Hammerschmidt P. Zum Hebel F. Hiltmann B. Krebs |
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Abstract: | Synthesis and Crystal Structures of Li4?2xSr2+xB10S19 (x ≈ 0.27) and Na6B10S18. Two Novel Thioborates with Highly Polymeric Macro-tetrahedral Networks Li4?2xSr2+xB10S19 (x ≈ 0.27) and Na6B10S18 were prepared from the reaction of strontium sulfide and lithium sulfide (sodium sulfide) with boron and sulfur at 700°C in graphitized silica tubes. Li4?2xSr2+xB10S19 (x ≈ 0.27) crystallizes in the monoclinic space group P21/c with a = 10.919(2) Å, b = 13.590(3) Å, c = 16.423(4) Å, and β = 90.48(2)°, Na6B10S18 in the tetragonal space group I41/acd with a = 14.415(3) Å, c = 26.137(4) Å. Both structures contain supertetrahedral B10S20 units which are linked through tetrahedral corners to form a three-dimensional polymeric network in the case of Na6B10S18 and one-dimensional chains in the case of Li4?2xSr2+xB10S19 (x ≈ 0.27). All boron atoms are in tetrahedral BS4 coordination (B? S bond lengths vary from 1.879(5) to 1.951(5) Å (1.875(10) to 1.987(9) Å)). The strontium and lithium (sodium) cations are located within large channels formed by the anions. |
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Keywords: | Thioborates synthesis crystal structures |
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