Albrecht R, Ruck M. Chalcogenides by Reduction of their Dioxides in Ultra-Alkaline Media.
Angew Chem Int Ed Engl 2021;
60:22570-22577. [PMID:
34375499 PMCID:
PMC8518872 DOI:
10.1002/anie.202107642]
[Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2021] [Indexed: 11/21/2022]
Abstract
The reaction of chalcogen dioxides ChO2 (Ch=Se, Te) with As2 O3 in a 30 molar KOH hydroflux at about 200 °C yielded crystals of potassium trichalcogenides K2 Ch3 with dimensions up to 2 cm. Arsenic trioxide acts as electron donor and is oxidized to arsenate(V). The new heterochalcogenide anion (TeSe2 )2- formed when starting from SeO2 and TeO2 simultaneously. The compound K2 TeSe2 crystallizes isostructural to K2 S3 and K2 Se3 . The unexpected redox reaction as well as the precipitation of hygroscopic compounds from an aqueous solution are attributed to a strongly reduced activity of water. The reactions were studied by Raman and UV/Vis spectroscopy. Depending on the concentration of As2 O3 , colorless monochalcogenide Ch2- or orange Se2 2- and purple Te2 2- anions are dominating the solutions.
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