Synthesis and Characterization of Ammonium Potassium Tellurium Polyoxomolybdate: (NH₄)₂K₂TeMo₆O₂₂·2H₂O with One-Dimensional Anionic Polymeric Chain [TeMo₆O₂₂]⁴⁻

• Main Authors: Lei Geng, Yunjian Wang
• Format: Article
• Language: English
• Published: MDPI AG 2021-04-01
• Series: Crystals
• Subjects: tellurium polyoxomolybdate; [TeMo₆O₂₂]⁴⁻ hexamolybdotellurate chain; crystal structure; hydrothermal synthesis
• Online Access: https://www.mdpi.com/2073-4352/11/4/375
• ISSN: 2073-4352

A new tellurium polyoxomolybdate hydrate (NH₄)₂K₂TeMo₆O₂₂·2H₂O was synthesized via the hydrothermal reaction method at 190 °C. The compound crystallizes in a one-dimensional tellurium polymolybdate [TeMo₆O₂₂]⁴⁻ chain structure. The anionic polymeric chain is composed of Mo₆O₂₂ hexamers bridged together through sharing four corner oxygen atoms on the electron lone-paired TeO₄ group. The Mo₆O₂₂ hexamer cluster is assembled from six distorted MoO₆ octahedra in an edge-sharing manner. The ammonium and potassium cations distribute around the [TeMo₆O₂₂]⁴⁻ chains and separate them from each other and maintain the charge balance. The thermal stability and optical properties of the compound were also investigated. The optical absorption data reveal that the compound is a wide band semiconductor with an optical band gap of 3.4 eV.