Potassium, Cesium, and Ammonium Peroxogermanates with Inorganic Hexanuclear Peroxo Bridged Germanium Anion Isolated from Aqueous Solution

• Published in: Inorganic chemistry Vol. 54; no. 16; pp. 8058 - 8065
• Main Authors: Medvedev, Alexander G, Mikhaylov, Alexey A, Churakov, Andrei V, Vener, Mikhail V, Tripol’skaya, Tatiana A, Cohen, Shmuel, Lev, Ovadia, Prikhodchenko, Petr V
• Format: Journal Article
• Language: English
• Published: United States American Chemical Society 17-08-2015
• ISSN: 0020-1669; 1520-510X
• DOI: 10.1021/acs.inorgchem.5b01293

Potassium (K6[Ge6(μ-OO)6(μ-O)6(OH)6]·14H2O, 1), cesium ammonium (Cs4.2(NH4)1.8[Ge6(μ-OO)6(μ-O)6(OH)6]·8H2O, 2), and potassium ammonium (K2.4(NH4)3.6[Ge6(μ-OO)6(μ-O)6(OH)6]·6H2O, 3) peroxogermanates were isolated from 3% hydrogen peroxide aqueous solutions of the corresponding hydroxogermanates and characterized by single crystal and powder X-ray diffraction studies and by Raman spectroscopy and thermal analysis. The crystal structure of all three compounds consists of cations of potassium and/or ammonium and cesium, water molecules, and centrosymmetric hexanuclear peroxogermanate anion [Ge6(μ-OO)6(μ-O)6(OH)6]6– with six μ-oxo- and six μ-peroxo groups. Peroxogermanates demonstrate relatively high thermal stability: the peroxide remains in the structure even after water release after heating to 100–120 °C. DFT calculations of the peroxogermanate [Ge6(μ-OO)6(μ-O)6(OH)6]6– anion confirm its higher thermodynamic stability compared to the hydroperoxo- and oxogermanate analogues.