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

Alexander G Medvedev; Alexey A Mikhaylov; Andrei V Churakov; Mikhail V Vener; Tatiana A Tripol'skaya; Shmuel Cohen; Ovadia Lev; Petr V Prikhodchenko

doi:10.1021/acs.inorgchem.5b01293

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

Inorg Chem. 2015 Aug 17;54(16):8058-65. doi: 10.1021/acs.inorgchem.5b01293. Epub 2015 Aug 4.

Authors

Alexander G Medvedev^{1

2}, Alexey A Mikhaylov^{1

2}, Andrei V Churakov¹, Mikhail V Vener¹, Tatiana A Tripol'skaya¹, Shmuel Cohen², Ovadia Lev², Petr V Prikhodchenko¹

Affiliations

¹ †Kurnakov Institute of General and Inorganic Chemistry, Russian Academy of Sciences, Leninskii prosp. 31, Moscow 119991, Russia.
² ‡The Casali Center of Applied Chemistry, The Institute of Chemistry, The Hebrew University of Jerusalem, Jerusalem 91904, Israel.

PMID: 26241061
DOI: 10.1021/acs.inorgchem.5b01293

Abstract

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.