13450-92-5Relevant articles and documents
Polygermane building blocks
Hlina, Johann,Baumgartner, Judith,Marschner, Christoph
, p. 5289 - 5295 (2010)
Tetrakis(trimethylgermyl)germane was prepared by the reaction of chlorotrimethylgermane and tetrabromogermane with lithium at -78 °C. Reaction with potassium tert-butoxide/18-crown-6 gave (Me3Ge) 3GeK·18-crown-6, which displayed typical reactivity with electrophiles. In the reaction of (Me3Ge)3GeSiMe 3 with tert-butoxide/18-crown-6 exclusive attack at the trimethylsilyl group was observed. Attempts to obtain a dimetalated species from (Me3Ge)3GeGe(GeMe3)3 and 2 tert-butoxide/2 18-crown-6 failed due to cleavage of the central Ge-Ge bond. The respective dianion was, however, accessible employing (Me3Si) (Me3Ge)2GeGe(GeMe3)2(SiMe 3) as the precursor.
A calorimetric study of germanium dibromide
Zelenina,Chusova,Stenin,Berezovskii
, p. 1911 - 1914 (2006)
The temperature dependence of the heat capacity of germanium dibromide was studied over the temperature range 8.3-314 K by adiabatic calorimetry. The enthalpy of formation of solid germanium dibromide was determined by solution calorimetry. Scanning calorimetry was used to obtain the thermodynamic characteristics of fusion of GeBr2. The thermodynamic characteristics of the Ge-Br system studied by us earlier were used to consistently calculate the consistent standard enthalpies of formation and absolute entropies of germanium bromides in the solid, liquid, and gaseous states. Nauka/Interperiodica 2006.
Synthesis of Germanium(I) bromide. A first step towards new Gemanium cluster compounds?
Schnepf, Andreas,Koeppe, Ralf
, p. 2914 - 2918 (2002)
Thermodynamic data for gaseous GeBr, derived from quantum chemical (DFT)-calculations show that this monohalide should be formed at 1550°C as a product of the reaction of elemental germanium with HBr at 1X10-2 mbar. Herein the design of an apparatus is described in which GeBr can be synthesized under these conditions and cocondensed with toluene at -196°C. Using this technique 3 g of a dark red X-ray amorphous solid could be prepared over a period of 3 hours and was identified to be GeBr. It is shown to undergo disproportionation at 90°C to give elemental germanium and germanium tetrabromide.
Chemical equilibria in the gas phase of the Ge-Br system
Zelenina,Titov,Chusova
, p. 43 - 46 (2007/10/03)
Thermodynamic function values were refined for two independent chemical reactions in the gas phase of the Ge-Br system.
Microwave-assisted Lewis acid catalysis: Application to the synthesis of alkyl- or arylhalogermanes
Laurent, Régis,Laporterie, André,Dubac, Jacques,Berlan, Jacques
, p. 2493 - 2495 (2008/10/08)
Under microwave irradiation, alkyl- or arylhalogermanes RnGeX4-n (R = Et, Bu, Ph; X = Cl, Br) are obtained by redistribution reactions of R4Ge with GeX4. These experimental conditions permit the synthesis of such compounds in good yield in a few minutes at atmospheric pressure. The direct Friedel-Crafts germylation of benzene and toluene by germanium tetrachloride also has been performed, but yields were low.
Formation of Halide Complexes of Methyl- and Inorganic Germanium(IV) in Aqueous Hydrohalogenic Acid Solutions
Sohrin, Yoshiki
, p. 3363 - 3371 (2007/10/02)
The reaction of methyl- and inorganic germanium(IV) hydroxides ((CH3)nGe(OH)4-n; n = 1, 2, or 3) with halide ions (X = Cl-, Br-, or I-) to form halide complexes ((CH3)nGeX4-n) in aqueous acidic solution has been investigated by liquid-liquid extraction, solid-liquid distribution (ion exchange), and 1H NMR spectrometry.It has been found that methylgermanium moieties are hard Lewis acids similarly to inorganic germanium(IV), because the stability constant of the halide complexes decreases in the order Cl- > Br- > I-.The stability constant for an X- ion increases as the number of methyl groups attached to the germanium atom increases.The species of inorganic-, monomethyl-, and dimethylgermanium are nonionic and have a tetrahedral structure in HX solution, and OJ- ions attached to the germanium atom are stepwise substituted by X- ions with an increase in HX activity.Trimethylgermanium alone forms a cation, when the activity of HX is not sufficiently high.These facts suggest that the transfer of a negative charge from methyl groups to the central germanium atom lowers the stability of the bond between the germanium atom (hard acid) and an OH- ion (hard base).
Chemistry of Germanium Atoms. II. Reactions of Thermally Evaporated Germanium Vapor with Organic Halides
Mochida, Kunio,Tashiro, Kumiko,Yoshida, Yasuhiro,Mizuno, Yasuhisa
, p. 1247 - 1250 (2007/10/02)
Thermally generated germanium atoms were found to react with organic halides by insertion into carbon-halogen bonds.The resulting germylenes abstracted halogens from organic halides to form trihalogermyl derivatives.Tetrahalogermanes were also formed by t
The Reaction of Germanium Atoms with Organic Halides
Mochida, Kunio,Tashiro, Kumiko
, p. 1105 - 1108 (2007/10/02)
Co-condensation of thermally evaporated germanium vapor with organic halides yields a mixture of trihalogermyl derivatives and tetrahalogermanes as major products.The nature of these reactions is discussed.
