Crystalline Ammonium Peroxogermanate as a Waste-Free, Fully Recyclable Versatile Precursor for Germanium Compounds

Abstract

High, nearly 100%, yield synthesis of ammonium peroxogermanate (APG), (NH 4 ) 6 [Ge 6 (μ-OO) 6 (μ-O) 6 -(OH) 6 ]•6H 2 O, is presented, and its crystal structure is determined by single crystal X-ray study. It comprises centrosymmetric hexanuclear peroxogermanate anions [Ge 6 -(μ-OO) 6 (μ-O) 6 (OH) 6 ] 6− with six μ-oxoand six μ-peroxo groups forming negatively charged layers. The space between these layers is filled by ammonium cations and water molecules, forming a highly stable structure due to hydrogen bonding. Highly soluble macroporous amorphous germanium oxide (HSGO) is then synthesized by mild treatment of APG. The compound forms highly oversaturated metastable germanium oxide solution with a solubility of 100 g/L, over 20 times higher than the solubility of amorphous germanium oxide. HSGO solution is a versatile reagent that can react with basic and acidic reagents to give a diverse range of salts including, e.g., germanium sulfide, germanium hydrophosphate, and potassium germanate. In the absence of acid or base, the aqueous HSGO solution yields hexagonal germanium oxide under ambient conditions.

Triphenyllead Hydroperoxide: A 1D Coordination Peroxo Polymer, Single-Crystal-to-Single-Crystal Disproportionation to a Superoxo/Hydroxo Complex, and Application in Catalysis

“…Adding an excess of 98 wt % H 2 O 2 obtained from serine perhydrate ([H 2 O 2 ]/[Pb] = 5:1) leads to a complete disappearance of this peak and the emergence of a broad resonance at δ −139.6 (Figure b), which reflects the replacement of the hydroxo by the hydroperoxo group in the coordination environment of lead­(IV) atoms. A similar high-field shift was previously reported for hydroperoxo/hydroxo substitution in the coordination environment of Sn­(IV). , The observed line broadening of the signal at −139.6 is attributed to the chemical exchange owing to reversible oligomerization of the triphenyl hydroperoxo lead­(IV) complex, which is also typical for other p-block elements in hydrogen peroxide-containing systems, as previously demonstrated for boron, germanium, , tin­(IV), ,, and tellurium­(VI) complexes . Oligomeric (Ph 3 Pbμ-OOH) n species can be considered as intermediates leading to the crystallization of the one-dimensional (1D) coordination polymer 1 .…”

Sodium and Potassium tert-Butyl Peroxide Hydrates: Crystal Structure and Properties

“…According to TGA, the weight loss of the samples on heating to 350°C under argon is 71.4 and 61.4% for the powders of I and II, respectively. Heating of the samples is accompanied by melting followed by evaporation of water in the range of 60-100°C, which was observed previously for the hydrates of peroxy complexes of germanium [18,19] and tellurium [20]. According to DSC data, several exothermic effects, indicating decomposition of peroxy groups with oxygen evolution and, possibly, subsequent reactions with participation of oxygen, are recorded in the 100-130°C range.…”

Identification of Barium Hydroxo-Hydroperoxostannate Precursor for Low-Temperature Formation of Perovskite Barium Stannate

“…The identification of the peroxoprecursor, BHHPS reveals that the route for low temperature barium stannate formation resembles another sol–gel approach based on tin alkoxide single-source precursor Ba 2 Sn 2 (thd) 4 (O i Pr) 8 , and the formation of other Sn­(IV) compounds from hydroperoxo and peroxobridged precursors. ,− We have also reported the analogous formation of germanate, antimonate, − tellurate , and even zinc oxide films and nanostructured materials from their respective peroxide and hydroperoxide precursors. In all these cases, peroxo bridged and hydroperoxo precursors such as peroxogermanates, , peroxostannates, , peroxoantimonates, peroxotellurates are first formed in aqueous hydrogen peroxide solutions, which are precipitated as films or nanostructured materials by a delicate regulation of the pH, or by the addition of hydrogen peroxide, ammonia or antisolvent.…”

“…14,24−28 We have also reported the analogous formation of germanate, 29 antimonate, 30−32 tellurate 33,34 and even zinc oxide films 35 and nanostructured materials from their respective peroxide and hydroperoxide precursors. In all these cases, peroxo bridged and hydroperoxo precursors such as peroxogermanates, 36,37 peroxostannates, 4,14 peroxoantimonates, 38 peroxotellurates 39 are first formed in aqueous hydrogen peroxide solutions, which are precipitated as films or nanostructured materials by a delicate regulation of the pH, or by the addition of hydrogen peroxide, ammonia or antisolvent.…”