Thiosilicate

In chemistry and materials science, thiosilicate refers to materials containing anions of the formula [SiS_2+n]²ⁿ⁻. Derivatives where some sulfide is replaced by oxide are also called thiosilicates, examples being materials derived from the oxohexathiodisilicate [Si₂OS₆]⁶⁻. Silicon is tetrahedral in all thiosilicates and sulfur is bridging or terminal. Formally such materials are derived from silicon disulfide in analogy to the relationship between silicon dioxide and silicates. Thiosilicates are typically encountered as colorless solids. They are characteristically sensitive to hydrolysis. They are from the class of chalcogenidotetrelates.

Structure of Fe₂(SiS₄). Fe is octahedral coordination, Si is tetrahedral. sulfides are bridging.^[1] Color code: S = yellow, Fe = blue, Si = orange.

Materials science

The LISICON (LIthium Super Ionic CONductor) include thiosilicates, which are fast ion conductors.^[2] Thiosilicates and related thiogermanates are also of interest for infrared optics, since they only absorb low frequency IR modes.^[3]

References

^ Vincent, H.; Bertaut, E. F.; Baur, W. H.; Shannon, R. D. (1976). "Polyhedral deformations in olivine-type compounds and the crystal structure of Fe₂SiS₄ and Fe₂GeS₄". Acta Crystallographica Section B Structural Crystallography and Crystal Chemistry. 32 (6): 1749–1755. Bibcode:1976AcCrB..32.1749V. doi:10.1107/S056774087600633X.
^ Morimoto, Hideyuki; Yamashita, Hideki; Tatsumisago, Masahiro; Minami, Tsutomu (1999). "Mechanochemical synthesis of new amorphous materials of 60Li2S·40SiS2 with high lithium ion conductivity". Journal of the American Ceramic Society. 82 (5): 1352–1354. doi:10.1111/j.1151-2916.1999.tb01923.x.
^ Yin, Wenlong; Feng, Kai; He, Ran; Mei, Dajiang; Lin, Zheshuai; Yao, Jiyong; Wu, Yicheng (2012). "BaGa₂MQ₆ (M = Si, Ge; Q = S, Se): A New Series of Promising IR Nonlinear Optical Materials". Dalton Transactions. 41 (18): 5653–5661. doi:10.1039/c2dt12493a. PMID 22434416.

[1] Vincent, H.; Bertaut, E. F.; Baur, W. H.; Shannon, R. D. (1976). "Polyhedral deformations in olivine-type compounds and the crystal structure of Fe₂SiS₄ and Fe₂GeS₄". Acta Crystallographica Section B Structural Crystallography and Crystal Chemistry. 32 (6): 1749–1755. Bibcode:1976AcCrB..32.1749V. doi:10.1107/S056774087600633X.

[2] Morimoto, Hideyuki; Yamashita, Hideki; Tatsumisago, Masahiro; Minami, Tsutomu (1999). "Mechanochemical synthesis of new amorphous materials of 60Li2S·40SiS2 with high lithium ion conductivity". Journal of the American Ceramic Society. 82 (5): 1352–1354. doi:10.1111/j.1151-2916.1999.tb01923.x.

[3] Yin, Wenlong; Feng, Kai; He, Ran; Mei, Dajiang; Lin, Zheshuai; Yao, Jiyong; Wu, Yicheng (2012). "BaGa₂MQ₆ (M = Si, Ge; Q = S, Se): A New Series of Promising IR Nonlinear Optical Materials". Dalton Transactions. 41 (18): 5653–5661. doi:10.1039/c2dt12493a. PMID 22434416.

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